factors influencing fine and gross motor development among
TRANSCRIPT
University of Calgary
PRISM: University of Calgary's Digital Repository
Graduate Studies The Vault: Electronic Theses and Dissertations
2017
Factors Influencing Fine and Gross Motor
Development among Children 24 Months of Age:
Results from the All Our Families Study
Dodd, Shawn X.
Dodd, S. X. (2017). Factors Influencing Fine and Gross Motor Development among Children 24
Months of Age: Results from the All Our Families Study (Unpublished master's thesis). University
of Calgary, Calgary, AB. doi:10.11575/PRISM/26147
http://hdl.handle.net/11023/3808
master thesis
University of Calgary graduate students retain copyright ownership and moral rights for their
thesis. You may use this material in any way that is permitted by the Copyright Act or through
licensing that has been assigned to the document. For uses that are not allowable under
copyright legislation or licensing, you are required to seek permission.
Downloaded from PRISM: https://prism.ucalgary.ca
UNIVERSITY OF CALGARY
Factors Influencing Fine and Gross Motor Development among Children 24 Months of Age:
Results from the All Our Families Study
by
Shawn Xavier Dodd
A THESIS
SUBMITTED TO THE FACULTY OF GRADUATE STUDIES
IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE
DEGREE OF MASTER OF SCIENCE
GRADUATE PROGRAM IN BIOLOGICAL SCIENCES
CALGARY, ALBERTA
APRIL, 2017
© Shawn Xavier Dodd 2017
ii
Abstract
Objective: The objective of this study was to identify factors influencing fine and gross motor
development of Albertan children at 24 months of age.
Methods: This is a secondary analysis of data from the All Our Families study, a prospective
pregnancy cohort. Multivariable logistic regression was performed to identify factors influencing
motor development.
Results: Early developmental delays, maternal abuse and maternal postpartum drug use were
associated with an increased odds of suboptimal gross motor development at 24 months of age.
Pregnancy complications were associated with a reduction in risk for gross motor delays. Early
developmental delays, NICU admission and maternal postpartum alcohol consumption were
associated with an increased risk for delays in fine motor development at 24 months of age.
Conclusion: Delayed motor development at 24 months of age may be mitigated through
detection and intervention of early cognitive, social and motor developmental delays.
iii
Acknowledgements
I would like to extend my sincere gratitude to my supervisors, Dr. Suzanne Tough and
Dr. Brent Hagel, for their support throughout my graduate studies. Suzanne, thank you for all the
effort you have dedicated to supervising me throughout my time with the All Our Families study.
Your patience and positive disposition has been tremendously encouraging. Brent, thank you for
your optimism and guidance. I am truly grateful for the mentorship you have both provided me
with during the past two years.
I would also like to recognize Dr. Alberto Nettel-Aguirre and Dr. Jason Cabaj for the
direction, support and expertise you both have brought to this project. I am honoured to have had
such a diverse and accomplished supervising committee.
To the All Our Families team, especially Mary Canning, Muci Wu and Nikki Stephenson,
thank you for all of your help throughout my time with the team. I appreciate your patience and
support, especially during the times I had a whirlwind of questions. Thank you for making me
feel part of the team!
A very special thank you to my family and friends who continue to support me in all my
endeavours. Your ongoing support and encouragement is appreciated beyond words.
Finally, I would like to acknowledge the participants of the All Our Families study, and
the Canadian Institutes of Health Research (CIHR) for their financial support throughout my
graduate studies.
iv
Table of Contents
Abstract ........................................................................................................................................... ii
Acknowledgements ........................................................................................................................ iii
Table of Contents ........................................................................................................................... iv
List of Tables ................................................................................................................................ vii
List of Figure and Illustrations ..................................................................................................... viii
List of Abbreviations and Nomenclature ....................................................................................... ix
CHAPTER ONE: INTRODUCTION ............................................................................................. 1
1.1 Problem Statement ................................................................................................................ 1
1.2 Background ........................................................................................................................... 2
1.2.1 Child Development ........................................................................................................ 2
1.2.2 Modern Theories of Motor Development ...................................................................... 4
1.2.3 An Overview of Motor Development ............................................................................ 9
1.2.3.1 Gross motor development ..................................................................................... 13
1.2.3.2 Fine motor development ....................................................................................... 14
1.2.4 Developmental Assessment Tools ............................................................................... 16
1.2.5 Population-wide developmental screening and the importance of at-risk profiles for
developmental delays ............................................................................................................ 21
1.3 Research Objectives ............................................................................................................ 23
1.4 Research Significance ......................................................................................................... 24
1.5 Knowledge Translation ....................................................................................................... 25
1.6 Summary of Thesis Format ................................................................................................. 26
CHAPTER TWO: REVIEW OF THE LITERATURE INVESTIGATING FACTORS
ASSOCIATED WITH GENERAL, FINE AND GROSS MOTOR DEVELOPMENT .............. 27
2.1 Methods............................................................................................................................... 27
2.1.1 Data Sources and Search Strategy ............................................................................... 27
2.1.2 Inclusion Criteria ......................................................................................................... 27
2.1.3 Exclusion Criteria ........................................................................................................ 28
2.1.4 Data Extraction and Synthesis ..................................................................................... 28
2.2 Results ................................................................................................................................. 29
2.2.1 Risk Factors for Delayed General Motor Development .............................................. 30
2.2.1.1 Sociodemographic factors ..................................................................................... 71
2.2.1.2 Maternal health factors ......................................................................................... 73
2.2.1.3 Pregnancy and birth outcome factors .................................................................... 76
2.2.1.4 Child health factors ............................................................................................... 78
v
2.2.1.5 Environmental factors ........................................................................................... 79
2.2.2 Risk Factors for Delayed Fine or Gross Motor Development ..................................... 81
2.2.2.1 Sociodemographic factors ................................................................................... 110
2.2.2.2 Maternal health factors ....................................................................................... 111
2.2.2.3 Pregnancy and birth outcome factors .................................................................. 113
2.2.2.4 Child health factors ............................................................................................. 114
2.2.2.5 Environmental factors ......................................................................................... 115
2.3 Discussion ......................................................................................................................... 116
2.2.1 Critical Appraisal of the Current Body of Knowledge .............................................. 116
CHAPTER 3: METHODS .......................................................................................................... 120
3.1 Study Design ..................................................................................................................... 120
3.2 The All Our Families Study .............................................................................................. 120
3.3 Data Collection ................................................................................................................. 122
3.4 Outcome Measures............................................................................................................ 125
3.5 Exposure Variables ........................................................................................................... 126
3.5.1 Sociodemographic Factors ......................................................................................... 126
3.5.2 Maternal Health Factors ............................................................................................. 126
3.5.3 Pregnancy and Birth Outcome Factors ...................................................................... 127
3.5.4 Child Health Factors .................................................................................................. 127
3.5.5 Environmental Factors ............................................................................................... 127
3.6 Statistical Methods ............................................................................................................ 135
3.6.1 Descriptive Statistics .................................................................................................. 135
3.6.2 Bivariate Analysis ...................................................................................................... 135
3.6.3 Multivariable Logistic Regression ............................................................................. 135
3.7 Ethics................................................................................................................................. 137
CHAPTER FOUR: FACTORS RELATED TO DELAYED FINE AND GROSS MOTOR
DEVELOPMENT AMONG ALBERTAN CHILDREN AT 24 MONTHS OF AGE ............... 138
4.1 Background ....................................................................................................................... 138
4.2 Methods............................................................................................................................. 140
4.2.1 The All Our Families Study ....................................................................................... 140
4.2.3 Assessment of Fine and Gross Motor Development.................................................. 141
4.2.4 Exposure Variables .................................................................................................... 142
4.2.5 Data Analysis ............................................................................................................. 146
4.3 Results ............................................................................................................................... 147
4.3.1 Participant Characteristics ......................................................................................... 147
4.3.2 Factors Associated with Delayed Gross Motor Development ................................... 157
vi
4.3.3 Factors Associated with Delayed Fine Motor Development ..................................... 159
4.4 Discussion: ........................................................................................................................ 160
CHAPTER FIVE: CONCLUSIONS .......................................................................................... 166
5.1 Summary of Findings ........................................................................................................ 166
5.2 Limitations ........................................................................................................................ 166
5.3 Strengths ........................................................................................................................... 168
5.4 Implications of Study Results ........................................................................................... 169
5.5 Recommendations for Future Research ............................................................................ 171
REFERENCES: .......................................................................................................................... 173
APPENDIX A: DESCRIPTIVE STATISTICS FOR THE POTENTIAL
SOCIODEMOGRAPHIC, MATERNAL HEALTH, BIRTH OUTCOME, CHILD HEALTH,
AND ENVIRONMENTAL FACTORS ..................................................................................... 207
vii
List of Tables
Table 1: Mean age for the attainment of six gross motor milestones ……………...…………... 13
Table 2: Summary of articles examining factors associated with general motor development in
children 1-66 months of age ………………….……………………………....…......... 31
Table 3: Summary of articles examining factors associated with fine and/or gross motor
development in children 1-66 months of age …………………………………...…….. 82
Table 4: Comparison of AOF participants to MES participants ……………………………… 121
Table 5: Candidate variables ………………………………………………………...………... 129
Table 6: Categorization of candidate variables ………………………………………...……... 131
Table 7: Participant characteristics……………………………………………………………. 148
Table 8: Descriptive statistics for the potential sociodemographic, maternal health, birth
outcome, child health, and environmental factors ………………………………….. 151
Table 9: Final multivariable logistic regression model of factors influencing gross motor
development at 24 months of age ..…………………………………………..……… 158
Table 10: Final multivariable logistic regression model of factors influencing fine motor
development at 24 months of age ………………………………….....……………. 160
viii
List of Figure and Illustrations
Figure 1: Overview of included and excluded articles ………………………………………... 29
Figure 2: AOF Participant Recruitment Timeline ………………………………………......... 123
Figure 3: AOF Response Rates ………………………………….…………………………..... 124
ix
List of Abbreviations and Nomenclature
Symbol Definition
AOF All Our Families Study
aOR Adjusted Odds Ratio
ASQ-3 Ages and Stages Questionnaire, Third Edition
BMI Body Mass Index
CI Confidence Interval
CPS Canadian Paediatric Society
HSQ Home Screening Questionnaire
IDEAL Study Infant Development, Environment, and Lifestyle Study
IQ Intelligence Quotient
IPV Intimate Partner Violence
MES Maternity Experiences Survey
NICU Neonatal Intensive Care Unit
OR Odds Ratio
PPD Parental Psychological Distress
SD Standard Deviation
SES Socioeconomic Status
WHO World Health Organization
1
CHAPTER ONE: INTRODUCTION
1.1 Problem Statement
Up to 15% of children1,2 between 3-17 years of age are reported as experiencing either
physical, intellectual or other developmental delays, making developmental delays the most
common childhood disability2. To identify children at risk of delay, screening tools compare a
child’s development to age-adjusted standards3. Though effective, lack of systematic use of these
screening tools has resulted in less than 30% of children with developmental delays being
identified prior to kindergarten3,4. This lag in identification hinders early, effective
interventions4.
Delayed motor development is among the earliest recognizable indicators of global
developmental complications5. Current theories suggest an interplay between sensorimotor
maturation and the acquisition of cognitive and linguistic skills6,7. New challenges and sensory
information encountered through active exploration are believed to shape a child’s social and
cognitive abilities. Moreover, the development of skills that enable a child to interact with their
environment increases the breadth of experiences available to them to refine their movement and
coordination. Given the dependence of cognitive and linguistic skills on sensorimotor
development, it is imperative to understand risk factors that predispose children to motor
development delays to ensure appropriate support and interventions are available to them5.
Discerning critical risk factors will aid both health care providers and caregivers of young
children in identifying those at increased risk of delayed motor development. Motor
developmental complications may be a marker of global developmental disabilities5;
consequently, the identification of children with increased risk of motor delays may enable
2
earlier and more effective interventions4, ultimately optimizing outcomes for children and
families.
1.2 Background
1.2.1 Child Development
The evolution from a dependant infant to an autonomous adult requires the maturation of
four domains: 1) gross and fine motor skills, 2) speech and language, 3) social, personal and
activities of daily life, and 4) performance and cognition8. The course of neurodevelopmental
and physical growth is orderly, cumulative, and directional9,10. Development is described as
orderly as its progression follows a logical sequence where the attainment of one milestone
provides the foundation for the development of another9. Cumulative development suggests that
any given stage of development includes all the previous changes including newly developed
skills. Lastly, directional development indicates that child development continually progresses
towards increasing complexity10.
Together, the orderly, cumulative, and directional process of development formed the
basis of Piaget’s theory of cognitive development10. In his theory, Piaget asserted that children
develop through the progression of four universal stages: 1) sensorimotor stage, 2) pre-
operational stage, 3) concrete operational stage and 4) formal operational stage. Piaget’s theory
posits that progression through these stages is sequential, where stages could not be skipped, but
it is possible for a child to never reach a stage of development10. Together, as a child progresses
through these stages, cognitive processes are enhanced and refined.
The sensorimotor stage of development lasts from birth until 24 months of age and
includes the child’s progression from innate reflex actions to intentional movement and
3
behaviour10,11. During this stage, there is an interplay between sensorimotor maturation and the
acquisition of cognitive and linguistic skills, whereby the development of motor skills enables a
child to increasingly interact with their environment6,7,10. The new challenges and sensory
information encountered through active exploration are believed to shape a child’s social and
cognitive abilities, such as object permanence: the understanding that an object continues to exist
even when out of sight10,11. Moreover, the development of skills enabling a child to interact with
their environment increases the breadth of experiences available to them to hone both fine and
gross motor skills. As a result of the interplay between motor and cognitive development, it has
been suggested that motor development may serve as a prerequisite for later cognitive
development involved in the preoperational stage of child development12.
From 2-7 years of age, a child progresses through the preoperational age of
development10,11. During this stage, a child begins to understand the representation of objects
through symbols, such as words. Though the use of symbols represents a marked increase in
social ability compared to the sensorimotor stage, the preschool-age children exhibit difficulty in
understanding or visualizing their environment from another’s perspective. Furthermore,
children’s cognitive abilities remain limited due to centration: the narrow focus on one aspect of
a situation while neglecting other relevant aspects10,11.
The preoperational stage leads to the concrete operational stage from 7-11 years of
age10,11. The concrete operational age reflects the beginning of logical thought, where a child can
begin to solve problems by applying rules such as conservation. Though children exhibit logic,
most children’s ability to think abstractly remains limited until 11 years of age when they enter
the formal operational stage. The formal operational stage continues into adulthood where an
individual can think hypothetically and reason deductively.
4
Piaget’s theory posits that as a child progresses through these stages, cognitive processes
are enhanced and refined10. Moreover, progression through these stages is sequential, where
stages cannot be skipped, but it is possible for a child to never reach a stage of development10.
Based on this theory, early stages of development provide the foundation for future development.
This perspective is supported by the work of Bushnell and Boudreau and their suggestion that
motor development may serve as a control parameter for later development12. In 1993, they
described that motor development is a prerequisite for the development of haptic perception and
depth perception. Moreover, in their investigation of postural control and cognitive development,
Wijnroks and Van Veldhoven found that poor postural control at 6 months was also associated
with difficulties in problem solving later in development6,13.
Given the importance of early motor development on later cognitive development6,7, it is
imperative to understand the processes underlying motor control to effectively protect and
promote optimal long-term cognitive function.
1.2.2 Modern Theories of Motor Development
Since Aristotle’s view that a child’s development is a product of their experiences, and
Plato’s view that a child is born with a developmental fate, theories of early infant development
have argued the influence of heredity and environment14. Here, the transition from the early
maturationist perspective, that saw heredity as the sole influence on motor development, to the
modern dynamic systems approach, that proposes a complex interaction between the body and
the environment11, will be described.
The maturationist approach posits that the process of motor development is governed by
heredity with little influence from the environment11. The description of infant motor
5
development through the maturational approach was first describe by Arnold Gesell, a
psychologist credited with being among the first to systematically investigate early infant
development11,15. Through his investigation, Gesell described the orderly progression of
development beginning in the fetal stage and progressing throughout the child’s early life.
Noting the distinguishable sequence of movement patterns exhibited by developing children,
Gesell created the Developmental Schedules that later became the United States’ first
developmental scales11.
Gesell’s commitment to the observation of child development led to his theory that motor
development could be explained by seven guiding principles11. Through these principles, Gesell
described the cephalocaudal and proximodistal progression of development and the asymmetric,
non-linear pattern of development. Though it has since been refined, the directionality and
pattern of development described by Gesell continues to be accepted11,15.
Influenced by the work of his predecessor’s, Gesell’s principles also maintained that
motor development is a morphogenetic process, whereby changes involved in development are
autonomous and not influenced by the surrounding environment11,15,16. As such, Gesell believed
that the sequence and rate of development was determined by the child’s genetic composition.
Though Gesell later noted that the child’s surrounding environment must be supportive and align
with the child’s skill set15, he believed that the environment had no influence on motor
development, but may be important in the development of personality11.
Shortly after Gesell began investigating child development, Myrtle McGraw also started
describing the sequence of motor development16. Considered by some as a maturationist,
McGraw believed that motor development was governed by cortical maturity rather than
genetics16,17. At birth, McGraw believed that the neonatal cerebrum lacked the maturity to illicit
6
motor control. As the infant developed, however, cortical centers matured, gaining increased
control of the lower brain and spinal cord, thereby enabling the development of motor skills11.
Through the maturation of the cerebrum, McGraw believed that the increased cortical control
prevented primary reflexes from being exhibited, a process she termed cortical inhibition. The
process of cortical inhibition, however, has since been refuted11,16,17.
McGraw’s perspective that motor development was governed by cortical maturity led to a
popular series of experiments aimed at investigating whether early motor skills could be
trained17. Of note was McGraw’s investigation of a set of twins named Jimmy and Johnny;
Johnny experienced transient hypoxia following birth, whereas Jimmy did not experience any
complications16,17. In her experiment, McGraw led Johnny through intensive training in both
universal and culturally-specific skills16. Upon comparing their long-term development, McGraw
reported that there was no significant mental or motor difference between the twins. These
results were suggested by some to support the maturationist perspective surrounding child
development17. Given that Johnny did not exhibit enhanced motor development following his
exposure to an intense training environment suggested that the surrounding environment could
not alter development. Moreover, some argue that McGraw’s experiments supported the belief
that the development of the structure, or the maturation of the infant’s cortex, led to motor
development16. Others, however, credit McGraw with developing the original foundation for the
bidirectional theory between brain structure and function17,18.
Following Gesell and McGraw, the maturationist approach to motor development lost
traction. Little work was conducted as many believed the experimental questions of that time
were sufficiently supported by the results from both psychologists16,17. Though the maturationist
7
perspective of motor development is no longer widely supported, the contribution of
developmental schedules remains a prominent tool in research19.
During the period of Gesell and McGraw, Nikolai Bernstein, a Russian psychologist, also
began writing his theories on motor development and control11,19. Though only translated into
English in 1967 and largely unrecognized until recently, Bernstein’s inquiries were directed to
understanding the control mechanisms driving motor movement19. By approaching movements
as dynamic systems, Bernstein described four fundamental problems with the maturationist
approach to motor development: 1) degrees of freedom, 2) redundancy, 3) contextual variations
and 4) change11. The degrees of freedom problem suggested that the numerous muscles and
joints in the body provide too many potential movements to each be under pre-programmed
control by the motor cortex. Rather, Bernstein hypothesized that movements were composed of
multiple subsystems. These subsystems were controlled by several central impulses throughout
the central nervous system that could be combined to produce movement, thereby reducing the
degrees of freedom11.
Bernstein’s redundancy problem highlights the innumerable possible ways of completing
similar tasks11. For example, each muscle is composed of numerous motor units, and each motor
unit is composed of a section of muscle fibres innervated by a single motor neuron. For a muscle
to exert a predetermined force on an object, there are countless possible combinations of motor
units that can be stimulated to exert the force. Furthermore, the possible combinations of
stimulated motor units increase exponentially when considering each movement involves
multiple muscles. As such, two approaches have been postulated for approaching the problem of
redundancy: 1) the central controller finds a unique solution to the motor task upon each
8
exposure; and 2) the central controller facilitates solutions that are equally acceptable, and
recycles these combinations.
Lastly, Bernstein’s contextual variations problem and his change problem describe how
movements must be adaptive to different environments and circumstances11. For example, if
each movement were a result of a specific set of stored neural commands, then a unique
command would be required for each variation in the context involved in the movement. As
such, different commands would be required for walking uphill, downhill and for each variation
involved in the surface, such as bumps and grooves. Moreover, given that the morphology of the
body changes substantially from the fetal-stage to a fully developed adult, a new set of
commands would be required for movements to be properly executed at each stage of life.
Together, these problems challenge the traditional maturational and information
processing perspectives of motor development. They argue that the cortex has a finite processing
ability that would be unable to sustain the variation and complexity of movements if each
movement is pre-programmed11.
Bernstein’s perspective of motor development was unique during this period as it
transcended the historical debate between nature versus nurture11,19. Rather, in his dynamic
systems approach, Bernstein recognized the importance that both the body and the environment
play in eliciting appropriate motor tasks. Unfortunately, Bernstein’s work was not appreciated
until the 1970’s, when the dynamical systems approach was expanded by Esther Thelen, to
describe our modern understanding of motor development11,19.
Similar to Gesell’s view of motor development, the dynamic systems approach to motor
development has foundational principles. These principles require that organisms be composed
of multiple self-organizing subsystems11. These subsystems, such as the musculoskeletal or
9
nervous systems, operate together to generate the most efficient movement for a given task21.
Under this principle, the emergence of new behaviours is the result of multiple subsystems
individually maturing. As proposed by Gesell, this maturation process is non-linear, where each
subsystem experiences periods of stability and instability, which may or may not coincide with
the maturity of other subsystems11. Moreover, dynamic systems theory proposes that changes in
one subsystem will impact other subsystems, and subsequently the system in its entirety21,22. As
such, new motor skills are exhibited during periods where the underlying subsystems have each
developed the maturity to support and illicit the new behaviour11.
The dynamic systems approach provides a holistic perspective to understanding motor
development11,19. As described by Bernstein’s contextual variations problem, a movement is a
response to a variety of biological and environmental variables. Together, the interaction
between these variables and the underlying subsystem dictates how the child responds and
generates appropriate movements. Given the support for the dynamic systems approach to motor
development, continued efforts are required to further understand the biological and
environmental factors that may influence motor development as well as identifying key
parameters that explain the behaviour of the system.
1.2.3 An Overview of Motor Development
Motor development is initiated during the embryonic stage of pregnancy and continues
well into adolescence11. Prenatal motor development begins at 5-6 weeks gestation as striated
muscles differentiate from the mesoderm23. As muscles differentiate, they react to direct
stimulation and produce movements known as myogenic movement11,24. Myogenic movement
begins with extension-like movements of the upper spine. At 8-9 weeks gestation, myogenic
10
movements include extensions of the arms and legs23. These jerky, uncoordinated fetal
movements, however, are only detectable through ultrasonography.
The fetal stage of pregnancy begins at 10 weeks gestation and is marked by the
completion of organ differentiation11. During the fetal stage, the fetus increases in size and by 13
weeks gestation, fetal movements are strong enough to be recognized by the mother25. Fetal
activity has been shown to increase in frequency through the first half of pregnancy, culminating
at 20 weeks gestation23. Following 20 weeks gestation, motor activity is reduced due to space
restrictions and fetal movements evolve from myogenic to neurogenic movements; movements
generated by the central nervous system11,23. The variation in fetal movement associated with the
latter half of pregnancy has also been shown to vary according to biological and environmental
factors. For example, motor activity during the third trimester has been shown to vary between
sexes, with males exhibiting increased movement compared with females23. Moreover,
extrauterine stimuli, such as sudden noises may also elicit fetal movement. Maternal smoking
has also been shown to reduce fetal movement; however, normal movement patterns are restored
during non-smoking periods23. Though the frequency of fetal activity decreases later in
pregnancy, the vigour of the movements increases.
Towards the end of the second trimester, neuromotor development is sufficient to begin
supporting primitive reflexes26. Primitive reflexes are complex, brainstem-mediated, automatic
movement patterns that are present at birth and initiated by specific stimuli27,28. The development
of these reflexes support the survival of newborns by enabling feeding or avoiding harm11,25,28.
For example, the rooting reflex is initiated by stimulating the baby’s cheek. Following
stimulation, the baby will respond by rotating their head in the direction of the stimulus. This
reflex supports the baby in locating the nipple during feeding28. The rooting reflex is
11
complemented by the sucking reflex that is initiated once an object enters the baby’s mouth.
Though some primitive reflexes exhibit clear survival origins, the purpose of other reflexes, such
as the Moro reflex, remains unclear and may be artifacts of our evolutionary past28.
As the central nervous system matures, voluntary movement is initiated and most
primitive reflexes become increasingly hard to elicit27. After 12 months postpartum, most
primitive reflexes are non-existent and will not be exhibited by neurologically intact children or
adults. The persistence or reappearance of these reflexes may be indicative of immaturity of the
nervous system or neurologic disorders23. As such, testing for these reflexes is integral to clinical
neurologic assessments throughout the life course.
Beginning at 2-3 months of age, infants develop the ability to maintain their posture
following environmental changes through the acquisition of postural reflexes11. Postural reflexes
are automatic movements that include righting reflexes, reflexes that enable the body to return to
its normal position following a movement, and equilibrium reactions, movements that restore the
centre of gravity following movement. These reflexes are distinct from primitive reflexes as they
involve multiple input modalities and require cortical integrity29. Moreover, though postural
reflexes support the development of later voluntary movement, they remain neurologically and
developmentally distinct from voluntary control11.
The final group of reflexes that exist prior to voluntary movement are locomotor reflexes
that are exhibited beginning at birth through 3-5 months of age11. Though locomotor reflexes are
insufficient to support locomotion, they resemble movements such as crawling, swimming and
stepping. Each of the reflexes are elicited in response to a specific stimulus, such as the stepping
reflex that occurs if the baby’s foot is placed on a flat surface with their body weight forward11.
12
Voluntary movements begin during the first 6-months of development and typically
conform to three general principles: 1) cephalocaudal development, 2) proximodistal
development, and 3) differentiation28. Cephalocaudal development refers to the progression of
development from the head towards the coccyx. Through the first 6-months of development,
coordination and movement are refined beginning with the head and neck, and later the arms and
hands. The subsequent 6 months includes the development of the trunk, arms and legs. The
cephalocaudal principle of development is complemented by the proximodistal principle of
development. The proximodistal principle suggests that motor development is refined beginning
at the centre of the body and progresses towards the extremities. As such, increased coordination
begins with the upper arm, followed by the forearm, hands and then fingers. Similarly,
coordination of the upper leg precedes coordination of the lower leg, feet and toes. Together, the
cephalocaudal and proximodistal principles describe the general patterns of motor
development28. The emergence of mathematical models involved in the dynamic systems
approach to motor development suggest, however, that some deviation from these patterns may
exist30.
The principle of differentiation suggests that motor development progress from general
movements to increasingly specific movements28. Early in development, responsive reactions
may elicit movements involving the entire body. Through development, however, these reactions
will become less generalized and movement of the extremities will become more purposeful.
Together, these principles provide an overview of the progression of motor development.
Motor development typically begins with gross motor movements of the head and trunk. As
gross motor movement extends to the extremities, fine motor movements are subsequently
refined.
13
1.2.3.1 Gross motor development
Gross motor skills are defined by the American Psychological Association Dictionary of
Clinical Psychology as activities or skills that use large muscles to move the trunk or limbs and
control posture to maintain balance31. The development of these skills begins with postural
control and the ability to control the head and neck11. Given the proportions of the head relative
to the body, infants cannot fully control the movement of their head until three months of age.
Conforming to the cephalocaudal principle of development, gross motor development
continues down the trunk as the infant develops the postural control to sit unsupported32,33. In
their study investigating the age of attainment of six gross motor skills across Ghana, India,
Norway, Oman and the United States, the World Health Organization (WHO) Multicentre
Growth Reference Study Group found that children began sitting without support at 6 months
(SD: 1.1 months; Table 1)32,33. Following sitting without support, postural control of the legs was
recorded to begin at 7.6 months of age (SD: 1.4 months) with the infant’s ability to stand with
assistance.
Table 1: Mean age for the attainment of six gross motor milestones (table adapted from
WHO Multicentre Growth Reference Study Group: WHO Motor Development Study32,33)
Gross Motor Milestone Mean age in monthsa (SD)
Sitting without support 6.0 (1.1)
Standing with assistance 7.6 (1.4)
Hands-&-knees crawling 8.5 (1.7)
Walking with assistance 9.2 (1.5)
Standing alone 11.0 (1.9)
Walking alone 12.1 (0.8) a The calculation in months involves the division of the estimate in days by 30.4375
14
The onset of locomotion begins with creeping, a rudimentary form of crawling where the
infant pushes themselves around while remaining on their stomach11. As the baby’s strength and
coordination improves, they begin to exhibit hands-and-knees crawling at 8.5 months of age
(SD: 1.7 months; Table 1)32,33. As described by the WHO Multicentre Growth Reference Study
Group, upright locomotion is typically not observed until 9.2 months of age (SD: 1.5 months),
when the child begins to walk with assistance. Walking with assistance, or cruising, begins with
the infant supporting themselves using both arms and legs11. This assisted movement refines the
infant’s postural skills eventually leading to unassisted walking by 1-year of age (mean: 12.1
months; SD: 0.8 months)32,33. The early steps in walking are supported by a wide stance and
uncoordinated, flat-footed steps11. With practice, the child’s stance narrows, increasing the
length of strides and allowing walking speeds to vary. The increase in stride length is supported
by the movement of arms, where opposite arm and legs move forward together25.
Children’s ability to walk and run is continuously refined until 5-6 years of age. At two
years of age, toddlers begin to exhibit a rudimentary running style that is characterized by stiff
legs and a lack of airborne time between each step25. By school-age, however, most children can
run, vary their speed and quickly change directions.
1.2.3.2 Fine motor development
Fine motor skills are defined by the American Psychological Association Dictionary of
Clinical Psychology as activities or skills that require coordination of small muscles to control
small, precise movements, particularly in the face and hands34. Fine motor development in the
face includes the refinement of visual-motor control. Beginning as early as 36 weeks gestation
eye movements are detectable35 and by 2 months of age, infants develop the ability to visually
15
track objects. Closely interconnected with visual function and attention, infants’ ability to track
objects assists the development of later fine motor movements, such as reaching and grasping.
Moreover, the synchronization of the hands and feet with the eyes assists infants in coordinating
movements with their dynamic surrounding environment11.
As the child ages, fine motor development progresses in a similar cephalocaudal and
proximodistal pattern as gross motor development. By 4 months of age, infants develop the gross
motor skills required to begin reaching for objects11,25. Early reaching, however, is characterized
by a series of jerky, uncoordinated movements25. The progression of fine motor development,
along with improved proprioception, supports reaching behaviours in becoming smoother and
more coordinated movements.
In addition to reaching, the child also must develop the skills necessary to grasp an
object11,25. Infants are born with a palmar grasping reflex where the fingers will curl around and
grasp an object that has stimulated their palm28. This reflexive grasp is strong enough to support
the infants weight, however, remains under involuntary control. As such, the reflexive grasp only
releases upon muscle fatigue. The transition between reflexive grasping to voluntary grasping
begins between 4-8 months of development25. During this transition, the infants will begin to
include their thumb when grasping and orient their hand in a direction to best grasp the object of
interest.
Together, the fine motor skills involved in reaching and grasping require many years to
become highly coordinated. Between 4-6 months of age, a child develops the ability to
manipulate each arm and hand individually25. By two years of age, the child is able to discern if
an object will require one or two hands to be manipulated, and elicit the appropriate action.
Moreover, between 2-3 years of age, the child begins to elicit coordinated actions involved in
16
dressing themselves, such as putting on clothes and using zippers. Intricate fine motor skills such
as fastening buttons or tying shoes, however, only emerges between 5-6 years of age25.
In sum, motor development is initiated during pregnancy and development is continuous
throughout childhood11,23,25,28. The emergence of fine and gross motor skills typically progress in
a cephalocaudal and proximodistal pattern11,25,28. Though the pattern and sequence of
development have been described, motor development is marked by considerable variability
between individuals.
1.2.4 Developmental Assessment Tools
As described above, the course of neurodevelopment is orderly, cumulative, and
directional8,9; however, developmental delays are common1,2. A recent American cross-sectional
study reported that 15%, or nearly 10 million children aged 3-17 years had a developmental
disability in 2006-200836. The identification of children experiencing developmental delays is
imperative as delays in early childhood development may be indicative of underlying neurologic
conditions or chronic developmental disabilities37. Moreover, evidence suggests that early
intervention strategies are effective at mitigating potential long-term repercussion of transient
developmental delays, thereby optimizing the outcomes of children38. As such, systematically
assessing child development has been proposed as an approach for identifying developmental
delays in childhood. To assess child development, two forms of testing exist: screening tests or
diagnostic tests. Screening tests aim to detect early disease or risk factors for a disease in an
asymptomatic individual38. The results of the test provide an estimate of the level of risk an
individual has for a disease and are used to determine if a diagnostic test is warranted. To avoid
missing any potential diseases, screening tools include cut-off scores for differentiating between
17
diseased and non-diseased individuals that are selected towards high sensitivity. As screening
tools are designed to assess the development of many individuals, they are generally affordable
and non-invasive. Contrarily, diagnostic tests aim to determine whether a symptomatic or
asymptomatic individual with a positive screening test result truly has a disease38. As diagnostic
tests are intended to limit the number of false positive diagnoses, diagnostic criteria are selected
towards high specificity.
In this section, the characteristics of developmental screening tools will be discussed. To
accurately measure development throughout childhood, assessment tools have been developed
that vary according to the reference used to evaluate a child’s development, the developmental
domains that are examined, and who assesses the child.
To evaluate a child’s progression through development, their attainment must be
compared with a reference point to determine if the child is progressing typically or if they are
experiencing possible delays11. To do so, two reference scales are commonly used in assessment
tools: 1) criterion-referenced tools, and 2) norm-referenced tools11,40. Criterion referenced tools
compare a child’s proficiency in a skill with an external criterion that may or may not be
standardized to a reference group. This comparison format provides a clear indication of what a
child can and cannot perform. As the external criterion may not be standardized, criterion-
referenced assessment tools are scored using absolute standards, where perfect scores are
desired40. Given this scoring structure, criterion-referenced assessment tools are particularly
useful in assessing child development longitudinally or following an intervention as scores are
reflective of the child’s ability, rather than the child’s ability compared with a reference
population. Though few developmental assessment tools are exclusively criterion-referenced
18
based, the Brigance Screens tool provides both criterion-referenced and norm-referenced
developmental scores40,41.
Norm-referenced assessment tools compare a child’s ability with a representative group40.
This style of comparison is more common among developmental assessment tools as scores can
be compared with age-adjusted means and standard deviations to assess if a child is progressing
typically or exhibiting possible delays. Though commonly used, norm-referenced tools have
been criticized. The comparison of child development relative to a reference group fails to
account for the variability in rate and sequence of development exhibited by children11. As such,
assessment tools are not applicable for establishing a diagnosis for a child. Rather, assessment
tools inform professionals whether the child is in need of more in-depth monitoring39,42.
An additional criticism of norm-referenced tools is generalizability11. Given the influence
of biological and environmental factors on development, norm-referenced tools are only
applicable to children whose characteristics are represented in the reference population. For
example, the Ages and Stages Questionnaire, 2nd edition was standardized based on a group that
varied educationally, economically and ethnically41. This population, however, was not
nationally representative of the United States of America and therefore appropriate caution must
be taken when utilizing this scale to ensure the standard sample reflects the participants
appropriately.
Developmental assessment tools also vary according to developmental domains they
assess. Many of the developmental assessment tools used in research assess multiple
developmental domains. For example, the Bayley Scales of Infant Development, 3rd edition
measures two composite scores, language and motor, using six subscales: 1) cognitive, 2)
receptive communication, 3) expressive communication, 4) gross motor, 5) fine motor, and 6)
19
social-emotional41. Other developmental assessment tools, however, only measure a single
domain. These include tools such as the Alberta Infant Motor Scale, that exclusively assesses
motor development from birth to 18 months of age43.
Further to variations in comparison groups and developmental domains assessed,
assessment tools also vary according to the type of assessor required to complete the tool. Tools
such as the Ages and Stages Questionnaire have been designed such that the primary caregiver of
the child can sufficiently complete the assessment41. The Bayley Scales of Infant Development,
however, must be completed by trained professionals. Traditionally, it was believed that parents
of children with disabilities tended to overestimate their child’s abilities and, therefore, scales
completed by professionals were preferred44. A study by Harris, however, described that
compared with standardized tests, parents were adept at identifying developmental delays
(sensitivity: 80.0%; specificity: 90.9%)44. Moreover, Bodnarchuk and Eaton also reported that
parental assessment of gross motor milestone attainment had strong agreement with the results
reported by trained professionals45.
In addition to the variability of the structure of developmental assessment tools, the
quality of each tool also varies. To measure the quality of an assessment tool, their estimated
reliability and validity are measured11. The reliability of assessment tools is a measure of how
well a tool can produce consistent results when repeated. For assessment tools, reliability is
generally measured through two tests: 1) intrarater reliability and 2) interrater reliability11.
Intrarater reliability measures the consistency of the results following a single assessor
administering the assessment repeatedly to an individual under constant conditions. Interrater
reliability, however, measures the agreement or correlation between the results obtained when
20
two different assessors administer the assessment to the same individual. For a developmental
assessment tool to be useful, there must be a high degree of intrarater and interrater reliability.
Validity of a developmental assessment tool measures the tool’s ability to accurately
measure the developmental domain of interest11. For infant developmental assessment tools,
validity is measured according to context, construct and criterion-related validity. A tool is said
to have high context validity if it appropriately measures the developmental domain of interest.
For example, if a developmental tool is used to investigate fine motor development, it would
have high context validity if the assessment included fine motor skills relevant to the age group
under investigation.
Construct validity of an assessment tool measures if the tool appropriately evaluates the
performance of the task of interest11. Through this measure, a tool is said to have high construct
validity if it can differentiate between two groups with known differences in capabilities.
Finally, criterion-related validity measures how well the tool works in comparison with
the gold-standard tool currently in practice11. To measure criterion-related validity, both
concurrent and predictive validity are measured. Concurrent validity measures the assessment
tool’s ability to predict a child’s development relative to the optimal tool currently in practice.
Predictive validity, however, measures the tools ability to accurately predict a long-term
outcome. For example, whether an assessment tool for motor development administered at two
years of age can accurately predict a child’s school grade in physical education at five years of
age.
21
1.2.5 Population-wide developmental screening and the importance of at-risk profiles
for developmental delays
The use of assessment tools to screen for disease is a practice that aims to reduce the
morbidity of disease through early identification and intervention45. To support the identification
of a myriad of diseases, countless types of screening tools have been developed and validated. In
practice, however, screening for all disease is inefficient as the cost of screening and potential
risk of over-referring patients may tax the available healthcare system with no significant benefit
to the population or individuals. As such, in 1968 the World Health Organization put forward ten
guiding principles for early disease detection: 1) the condition sought should be an important
health problem; 2) there should be an accepted treatment for patients with recognized disease; 3)
facilities for diagnosis and treatment should be available; 4) there should be a recognizable latent
or early symptomatic stage; 5) there should be a suitable test or examination; 6) the test should
be acceptable to the population; 7) the natural history of the condition, including development
from latent to declared disease, should be adequately understood; 8) there should be an agreed
policy on whom to treat as patients; 9) the cost of case-finding (including diagnosis and
treatment of patients diagnosed) should be economically balanced in relation to possible
expenditure on medical care as a whole; and 10) case-finding should be a continuing process and
not a "once and for all" project45. Together these principles aim to support the healthcare
community in identifying disease whose morbidity may be reduced through screening.
When applying the WHO’s principles for early disease detection, there is support for
screening children with developmental delays. For example, as one of the most common
childhood disabilities, developmental disabilities are an important health problem2. To identify
delays, reliable and valid screening tools that can be administered in the home or at well-baby
22
physician visits have been designed to screen child development11,41. Moreover, given the long-
term implications associated with developmental delays, such as learning and behavioural
difficulties or later functional impairment, untreated developmental delays have the potential to
significantly tax the healthcare system46. What currently lacks to support a population-based
screening strategy for developmental delays is evidence supporting acceptable treatments for
those with delays. Consequently, in 2016 the Canadian Task Force on Preventive Health Care
was called to assess the evidence for effectiveness of population-based screening in primary care
settings for children aged 1-4 years46. The goal of this review was to address if the health
outcomes of children who would go unidentified through standard clinical practice could be
improved through population-based screening. To do so, the evidence of the benefits and harms
of developmental screening and treatment were reviewed.
The results of their systematic review informed their recommendation against screening
for developmental delay using standardized tools in children aged one to four years with no
apparent signs of delay, and whose parents or clinicians have no concerns about development46.
This recommendation, however, does not apply to children who present with signs or symptoms
that could indicate developmental problems, or whose development is being closely monitored
because of identified risk factors.
Given the Canadian Task Force on Preventative Health Care’s recommendation,
identification of children with developmental delays remains the responsibility of primary
caregivers and health care providers. To successfully identify children with developmental
delays, a strong relationship between primary caregivers and health care providers is required38.
Studies have reported that when questioned systematically about their child’s development,
primary caregivers provide accurate information and can identify delays38. Additionally, primary
23
care providers may also play an instrumental role in the identification of children with delays
given their longitudinal relationship with their patients. Through this longitudinal relationship,
primary care providers may recognize biological, sociodemographic or environmental factors
influencing a child’s development. If care is infrequent or discontinuous, however, factors
influencing development may go unrecognized and developmental delays unnoticed. As such, to
support Canadian primary caregivers and health care providers in assessing potential risk factors
for delayed development, it is imperative to inform a contemporary at-risk profile for
developmental delays15. An at-risk profile for Canadian children will ensure questions posed to
caregivers concerning a child’s development are relevant and evidenced-based. Furthermore, an
at-risk profile will inform health care providers of risk factors for developmental delays that
require assessment during healthcare visits.
Ultimately, by developing a contemporary at-risk profile for developmental delays,
diagnosis may be made early in development, maximizing the outcomes of therapy and
minimizing families’ stress5,38.
1.3 Research Objectives
1. To determine factors associated with delayed fine motor development at 24 months of
age.
2. To determine factors associated with delayed gross motor development at 24 months of
age.
24
1.4 Research Significance
Motor development may be among the first symptoms of global development delay or
delays in cognitive development5,37. By discerning critical risk factors, our study aims to inform
the development of a contemporary at-risk profile for both delayed fine and gross motor
development. The development of these at-risk profiles will support clinicians and caregivers of
young children in identifying children at increased risk of delayed motor development. As
complications in motor development may be indicative of global developmental disabilities5, the
identification of children at risk of delays may enable earlier access to instructed physical
activity sessions such as well-resourced play environments supported by teachers or trained staff.
Earlier access to these interventions may increase their effectiveness4 and ultimately optimize
outcomes for children and families.
Additionally, this study will contribute to the few Canadian studies currently existing in
the literature. As children of different countries are exposed to different factors such as cultural
expectations of motor skills, poverty, poor healthcare accessibility and different physical
environments47, research targeting Canadian children is essential to support the development of a
relevant at-risk profile of motor development delays. Using data from the All Our Families
(AOF) cohort, a longitudinal pregnancy cohort with detailed information about maternal and
infant demographics, lifestyle, mental health, family life and development during the perinatal
and early childhood period, this study will elucidate risk factors for motor development delays
among Albertan children48.
25
1.5 Knowledge Translation
To support the identification of children with delayed motor development, the results
from this study will be disseminated to community partners, health care providers and
educational institutions.
Community partners, such as the First 2000 Days Network, Alberta Health Services
Parenting Support, the Alex Centre and Parent Link Centre have a goal of informing the pregnant
and parenting population of healthy parenting practices and child development. As such, it is
important to advise these organizations of the novel findings, especially as they relate to
Canadian children. To ensure these organizations are informed, the results will be presented at
the organizations’ meetings and included in the All Our Babies/Families annual reports.
Furthermore, efforts will be made to investigate if local organization are interested in publishing
these results in their own resources, such as their website or newsletter. Knowledge translation
initiatives targeting the general populace will include disseminating results via the All Our
Families Study website and social media accounts. Parent participants will be notified of results
via All Our Families study newsletters.
To inform policymakers and primary health care providers of the implications of this
study, these results will be disseminated via peer-reviewed publications and presented at
scientific meetings related to maternal and child health. Networking efforts will be made to
ensure professors and staff at education institutions such as the Bachelor of Child Studies
program at Mount Royal University are aware of these results. By informing professors and staff
of our results, the risk and protective factors associated with delayed motor development at 24
months of age may be discussed with future child care providers and child health experts.
26
By informing stakeholders involved in early child development, children with increased
risk of motor delays may receive earlier and more effective interventions, ultimately optimizing
their developmental outcomes.
1.6 Summary of Thesis Format
This thesis is composed of five chapters. This chapter provided an overview of the
background related to child development and tools used to assess development. Chapter two
summarizes a systematic review of the literature investigating risk and protective factors related
to motor development. Chapter three provides a detailed account of the methodology used to
identify and test factors related to both fine and gross motor development. Chapter four presents
the results from the analysis of risk and protective factors influencing motor development in
children two-years of age. Chapter five provides a summary of the results, their practical
implications and suggestions for future research.
27
CHAPTER TWO: REVIEW OF THE LITERATURE INVESTIGATING FACTORS
ASSOCIATED WITH GENERAL, FINE AND GROSS MOTOR DEVELOPMENT
2.1 Methods
2.1.1 Data Sources and Search Strategy
A literature search was performed using CINAHL (1982-June 2, 2016), EMBASE (1980
– June 2, 2016), HealthSTAR (1975 – June 2, 2016), MEDLINE (1946 – June 2, 2016) and
PsycINFO (1803-June 2, 2016). Databases were search using the following keywords: “risk
factor”, “protective factor”, “marker”, “predict*”, “determinant*”, “correlate*”, “associate*”,
“motor development”, “delayed motor development” and “motor skill”. The following search
queries were performed:
1) “Risk Factor” or “Protective factor” or “Marker” or “Predict*” or “Determinant*”
or “Correlate*” or “Associat*”
2) “Motor Development” or “Delayed Motor Development” or “Motor skill”
3) “Search query #1” and “search query #2”
The literature identified using the aforementioned search strategy underwent a title and
abstract review for relevant articles. Each article then underwent a full-text review, where those
that failed to meet the inclusion or met the exclusion criteria were excluded. Bibliographies of
select articles were also reviewed to identify other relevant publications. The results of the
screening process are summarized in (Figure 1).
2.1.2 Inclusion Criteria
Inclusion criteria are as follows: 1) English articles; 2) articles published in a peer-
reviewed journal; 3) studies that assessed gross or fine motor development using validated
28
scales; and 4) human participants between 1-66 months of age (if age not reported, standard
regional age range for a given school grade was used to determine eligibility – e.g. Kindergarten
in Alberta = 5 years of age). The age range of 1-66 months was selected as validated
developmental scales (e.g. Ages and Stages Questionnaire, Bayley Scales of Infant Development
and Peabody Developmental Motor Scales) typically assess development up to a maximum of 66
months of age41. By including studies within this age range, a comprehensive list of risk factors
could be identified and their potential influence on motor development at 24-months of age can
be explored.
2.1.3 Exclusion Criteria
Exclusion criteria are as follows: 1) non-analytic designs; 2) studies with less than 30
participants; and 3) studies conducted in middle and low income countries. Studies with sample
sizes less than 30 participants were excluded as these studies may not contain sufficient power to
reject false null hypotheses. Studies conducted in middle income and developing countries were
not included due to potential differences in children’s exposure to risk factors such as cultural
expectations of motor skills, poverty, malnutrition, poor health, and different physical
environments47.
2.1.4 Data Extraction and Synthesis
The study design, study population, the screening tool used to assess motor development
and the results from relevant articles were extracted. Data are summarized in Table 2 and 3, to
highlight the risk factors for either general, fine or gross motor development.
29
2.2 Results
Of the 6358 original articles identified, 142 articles were selected for full-text review
(Figure 1). Twenty-six articles were excluded following full-text review as they were either
conducted in middle income or developing countries, children were assessed at ages beyond the
scope of this review or the articles did not segregate motor development in their investigation of
neurodevelopment.
Figure 1: Overview of included and excluded articles
30
Given the multitude of screening tools available, motor development has been assessed
using three classifications: 1) general motor development, 2) fine motor development and 3)
gross motor development. Here, the socio-demographic, maternal health, pregnancy and birth
outcome, child health, and child environmental risk factors identified from the literature will be
described for each definition of motor development.
2.2.1 Risk Factors for Delayed General Motor Development
A summary of the included articles assessing general motor development are presented in
Table 2.
31
Table 2. Summary of articles examining factors associated with general motor development in children 1-66 months of age
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Abbott et
al., 200049
Prospective
cohort study
Convenience sample of
43 English-speaking
mother-baby dyads.
Infants were aged 6
weeks-5 months.
Intended care for the
infant was in the home
for their first 8 months
(at least 4 days a week).
- Alberta Infant
Motor Scale (AIMS)
at 8 months of age.
- Assessed general
motor development
- HOME Inventory Scale
- Parental expectations (Maternal
version of AIMS scale: MAIMS)
- Infant general health and mood
- Any health conditions
- How infant practiced new
activities
- equipment used by infant
- if infants enjoyed playing on the
floor
- No significant correlations between
HOME Inventory and motor
development
- No significant relationships found
between parental expectations of
development at 5 months and actual
motor development at 8 months
Abbott &
Bartlett,
200050
Prospective
cohort study
Convenience sample of
43 English-speaking
mother-baby dyads.
Infants were aged 6
weeks-5 months.
Intended care for the
infant was in the home
for their first 8 months
(at least 4 days a week).
- Alberta Infant
Motor Scale (AIMS)
at 8 months of age.
- Assessed general
motor development
- Equipment used by infant during
play
- Significant correlations were found
between total equipment use and
motor development
- Significant correlations between use
of exersaucer, highchair and infant
seat and motor development
- No correlations found for jolly
jumper, walker, playpen, infant swing
and the other category
Aiello &
Lancaster,
200751
Prospective
cohort study
Sample of 71 adolescent
mother-infant dyads
recruited antenatally in
southeastern
Melbourne, Australia.
Infants were 41male
and 30 females.
Mothers were first-time
mothers, proficient in
English, absent of
intellectual disabilities,
- Bayley Scales of
Infant Development,
2nd edition at 2 years
of age.
- Assessed general
motor development
- Adolescent’s Separation-
individuation Process Inventory
- Adolescent’s Maternal Postnatal
Attachment Scale
- Adolescent’s Maternal
Separation Anxiety Scale
Adolescent’s Parental Bonding
Instrument
- Demographics (age, ethnicity,
relationships, living arrangements,
pregnancy history)
- Significant correlations with motor
development: living arrangements
(living with parent/s in early
postpartum correlated with poor
motor performance), infant age at
assessment,
- No correlations found with: infant
gestational age or sex, mother care,
mother overprotection, separation-
individuation, maternal-infant
attachment or maternal separation
anxiety.
- The proportion of variance in motor
32
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
development was not significantly
predicted by any of the factors
Arendt et
al., 199852
Prospective
cohort study
A sample of 167 12-
month olds and their
mother were recruited
and assessed. Mothers
were over 17 years of
age and did not have
any of the following:
psychiatric problems,
low intellectual status,
HIV positive, positive
drug test for PCP,
amphetamines,
barbiturates or heroin.
Infants weighed more
than 1500 grams at
birth.
- Bayley Scales of
Infant Development,
2nd edition at 12
months of age
(assessed general
motor development)
- Movement
Assessment of Infants
- Test of Sensory
Functions in Infants
- Infant Behavior
Record of the Bayley
Scales of Infant
Development
- Maternal and infant demographic
and medical characteristics
(maternal age, race, gravidity,
number of prenatal visits, type of
medical insurance, APGAR score,
gestational age, gender, head
circumference birth weight and
length
- Maternal Postpartum Drug
Interview
- When gestational age was covaried,
cocaine exposure displayed a trend
for lower psychomotor scores
- No confounders correlated with the
Bayley Scales of Infant Development
- Maternal age was correlated with
Movement Assessment of Infants
scores
- Primitive reflex scores were
correlated with number of cigarettes
and number of drinks per week
- Automatic reactions were correlated
with maternal age and number of
prenatal visits
- Regression results for Test of
Sensory Functions in Infants:
Adaptive Motor predicted by number
of prenatal visits; Tactile
Responsivity and Visual-Tactile
Coordination predicted by severity of
cigarette use;
- Regression results for Movement
Assessment of Infants: Primitive
reflexes predicted by severity of
cigarette use
- Regression results for Infant
Behavior Record of the Bayley
Scales of Infant Development:
Activity predicted by maternal age,
number of prenatal visits, parity
Astley et
al., 199053
Prospective
cohort study
A sample of 136
mother-child were
enrolled. 68 infants
were exposed to
marijuana via lactation
- Bayley Scales of
Infant Development,
1st edition at 1 year of
age
- Alcohol, tobacco and other drugs
use, demographic characteristics,
obstetric characteristics, lactation
status, use of supplemental
formula during lactation
- Infants exposed to marijuana for the
first month of lactation had
significantly lower mean
psychomotor scores than infants with
no marijuana exposure
33
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
and 68 were unexposed. - Assessed general
motor development
- Covariates: maternal age, height,
race, income level, education,
marital status, pregnancy history,
weight gain, tobacco, coffee,
alcohol and psychoactive drug use
during pregnancy and lactation,
marijuana use during pregnancy,
paternal alcohol and tobacco use
during conception and during
postpartum period, gestational age
and sex
- Exposure to cocaine via breastmilk
or alcohol during gestation also had a
significant adverse effect on
psychomotor development
Aylward et
al., 199254
Prospective
cohort study
A sample of 45
seronegative HIV
infants, 12 seropositive
HIV infants and 39
seroreverter HIV infants
between the ages of 5.5-
24 months of age were
enrolled. Infants were
excluded if they
weighed less than 1500
grams at birth, were less
than 34 weeks’
gestation or were
admitted to the neonatal
intensive care unit for
longer than 24 hours.
- Bayley Scales of
Infant Development,
1st edition at 6-, 12-,
18-, 24-months of age
- Assessed general
motor development
- Substance abuse in utero - Seropositive infants score
significantly lower on psychomotor
development than non-infected
infants
- No significant difference in
psychomotor scores among infants
exposed to substance abuse in utero
and non-exposed infants
Bedford et
al., 201655
Cross-
sectional
study
A sample of 715 UK-
based parents of 6- to
36-month-old children
were enrolled.
- Milestones adapted
from standardized
assessment tools.
- Demographic information
(child’s age, sex, maternal
education)
- Touchscreen usage (number of
devices in home, child’s number
of devices, frequency of use, age
at first use)
- Controlled variables: early
developmental milestones, maternal
education and, infant age and sex.
- No significant associations found
between gross motor (walking) and
language (combining two words)
milestones and touchscreen use
- Significant association between fine
motor milestone attainment (staking
blocks) and touchscreen use
34
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
- Age of first use and age of devices
was associated with staking blocks
Belfort et
al., 201156
Prospective
cohort study
A sample of 613 infants
born <33-weeks’
gestation from the DHA
for Improvement of
Neurodevelopmental
Outcome trial.
- Bayley Scales of
Infant Development,
2nd edition at 18
months of age
- Assessed general
motor development
- Infant Anthropometry: infant
weight and length, head
circumference,
- Demographic and clinical
information (gestational age,
breastfeeding, NICU diagnoses,
postnatal steroids exposure,
maternal smoking during
pregnancy, parental education)
- Home Screening Questionnaire
- Greater weight gain from first week
postpartum to gestation age 40 weeks
was associated with higher Bayley
Scales of Infant Development scores
- From term to 4 months of age,
greater weight gain and linear growth
were associated with higher
psychomotor development scores (no
associations found with BMI or head
growth)
Bendersky
& Lewis,
199457
Prospective
cohort study
A sample of 175
families were recruited.
Eligibility require the
infant weight 2000
gram or less at birth and
were treated in the
neonatal intensive care
unit.
- Bayley Scales of
Infant Development,
1st edition between
18-24 months of age
> Assessed general
motor development
- Sequenced
Inventory of
Communication
Development
- Perinatal and demographic
variables collected from maternal
obstetrical and infant neonatal
medical records
- Medical complications score
(number of common
complications of prematurity)
- Environmental Risk Variables
(parental education and
occupation, minority status,
number of children under 18 years
of age living in house, parents
living together, positive stressful
life events, negative stressful life
events, HOME Interview, social
support, quality of mother-child
interaction)
- None of the environmental risk
variables made significant
independent contributions to the
psychomotor score (3.9% of
explanatory power of the variance)
- Intraventricular hemorrhage and
medical complications scores were
significantly related to psychomotor
scores.
- Mental developmental index was
predicted by both environmental and
biological risk variables.
- Receptive communication was
explained more by environmental risk
variables than early medical
conditions
- Variance in expressive language
was minimally explained by
environmental and biological risk
variables
Black &
Nitz,
199658
Cross-
sectional
study
A sample of 79
adolescent mothers and
their child were
recruited. Among the
infants, 37 were
- Bayley Scales of
Infant Development,
1st edition (mean age
of children = 12.4
months, SD = 5.7
- Grandmother co-residence
- Perceived Stress
- Perceived family support
- Maternal perception of children’s
temperament
- Maternal education, parity and
mealtime competence was associated
with motor development
- Within the failure to thrive group,
grandmother co-residence was
35
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
categorized at failure to
thrive and 42 had
adequate growth.
months) - Parental warmth and children’s
competence during mealtime
associated with poorer motor
development
- Within the adequate growth group,
grandmother co-residence was
associated with increased motor
development
Brown et
al., 201059
Prospective
cohort study
A sample of 10700
children were recruited
in the Early Childhood
Longitudinal Studies –
Birth Cohort.
- Bayley Short Form
– Research Edition at
9 and 48 months
(assessed general
motor development)
- Age at assessment, poverty,
race/ethnicity
- Maternal alcohol consumption
per week during pregnancy
- Nursing Child Assessment
Teaching Scale
- Behavior Rating Scale
- Infant/Toddler Symptoms
Checklist
- Age and ethnicity (Black or Pacific
Islander) associated with increased
motor subscale scores
Casper et
al., 201160
Prospective
cohort study
A sample of 55 infants
from mothers who took
selective serotonin
reuptake inhibitors
major depressive
disorder in pregnancy.
Thirty-eight mothers
were recruited before or
early in pregnancy and
17 directly postpartum.
- Bayley Scales of
Infant Development,
2nd edition between
12-40 months of age
- Assessed general
motor development
- Confirmation of major
depressive disorder, Beck
Depression inventory, Hamilton
Depression Scale and Centre for
Epidemiological Studies –
Depression Scale
- Sociodemographic information, a
medical, family, and psychiatric
history and information about the
index pregnancy
- Neonatal and obstetrical records
- Antidepressant use (dosage and
type)
- Use of alcohol and smoking
- Increased length of antidepressant
exposure significantly increased the
odds of low Apgar scores
- Activity/muscle tone subscale of
Apgar score significantly reduced by
longer antidepressant exposure
- Psychomotor Developmental Index
and Behaviour Rating Scale scores
were negatively correlated with
increased duration of antidepressant
exposure
- Infants with early exposure were
rated significantly higher on
psychomotor development than
infants with continuous exposure
- Apgar scores did not significantly
predict psychomotor development or
behaviour rating scale
- Psychomotor development was
positively correlated with Behaviour
rating scale scores
36
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Cohen et
al., 201161
Prospective
cohort study
A sample of 229
children were recruited
into the
Neurodevelopmental
Effect of Antiepileptic
Drugs study. Pregnant
women with epilepsy
were on monotherapies,
and had IQs above 70,
no history of syphilis,
HIV progressive
cerebral disease or other
major diseases. Mothers
also were compliant
with prescription and
were not taking any
other known teratogen.
- Bayley Scales of
Infant Development,
2nd edition between
36-45 months of age
- Assessed general
motor development
Potential confounders: age,
education, employment,
race/ethnicity, seizure/epilepsy
types and frequency, antiepileptic
drug dosage, compliance and SES,
USA vs UK, preconception folate
use, use of alcohol, tobacco or
other drugs during pregnancy,
gestational age, birth weight,
breastfeeding, childhood medical
disease
- Maternal IQ: Test of Nonverbal
Intelligence-3rd edition, Wechsler
Abbreviated Scale of Intelligence,
National Adult Reading Test
- Antiepileptic Drugs:
carbamazepine, lamotrigine,
phenytoin, valproate
- Maternal IQ, standardized drug
dosage, gestational age at delivery
and site location were all
significantly related to psychomotor
scores.
- Higher doses of valproate and
carbamazepine were associated with
lower psychomotor scores and lower
adaptive performance ratings
- Adaptive performance ratings were
significantly higher in infants from
mothers receiving education beyond
high school
- Adjusted mean performance on the
BASC scales did not differ between
drug groups
- higher doses of valproate during
pregnancy reported with increased
problems with child’s social sills
- Valproate had significantly greater
percentage of children at risk for
ADHD than the national Centre for
Disease Control estimates
Daniels et
al., 200262
Prospective
cohort study
A sample of 1207
infants were randomly
selected from the
Collaborative Perinatal
Project. Children were
eligible if they were a
liveborn singleton, had
3-mL of maternal third
trimester serum, and
completed the Bayley
Scales of Infant
Development.
- Bayley Scales of
Infant Development,
1st edition at 8 months
of age
- Assessed general
motor development
- Exposure to Polychlorinated
Bisphenyls
- Covariates: maternal race,
education, socioeconomic index,
intelligence quotient, marital
status, prenatal smoking, pre-
pregnancy BMI, third trimester
serum triglycerides, total
cholesterol, and
dichlorodiphenyldichloroethylene
level, birth order, gestational age,
breastfeeding,
- No association between maternal
serum Polychlorinated Bisphenyls
and psychomotor development or
mental development
- Relationship between maternal
serum Polychlorinated Bisphenyls
not affected by individual or center-
level characteristics, maternal age,
BMI, SES or smoking status
Datar &
Jacknowitz,
Prospective
cohort study
A subset of 6750
singleton births, 625
- Bayley Short Form
– Research Edition at
- Twin type (monozygotic or
dizygotic)
- In total sample, very-low-birth
weight and moderately-low-birth
37
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
200963 twin pairs and 50 twins
and high-order births
were included from the
Early Childhood
Longitudinal Study –
Birth Cohort.
9 months and 2 years
of age
- Assessed general
motor development
- Birth weight and small-for-
gestational age
- Child height, weight, sex,
race/ethnicity, first birth, twin or
higher-order, gestational age,
- Maternal height, age, education,
marital status, household income,
US region, urbanicity, smoking or
alcohol use during pregnancy, at-
risk pregnancy, labour/delivery
complications,
- Prenatal Care Utilization Index
weight were significant
disadvantages to mental and motor
development at 9-months of age. The
effects persist for mental
development, but not motor
development at 2 years of age
- Within-twin analysis (control for
maternal and environmental factors)
show that very-low-birth weight is
associated with poor mental and
motor development at 9 months but
not 2 years. Moderately-low-birth
weight is associated with poor mental
development at 9 months also
- Within-identical twin analysis
(control maternal, environmental and
genetic factors) show birth weight is
not associated with mental or motor
development at 9 months or 2 years
- small-for-gestational age associated
with poorer mental and motor scores
across sample, however, no
association is found in within-twin
analyses
Dubek-
Shriber &
Zelazny,
200764
Cross-
sectional
study
A convenience sample
of 125 4-month old
infants were recruited.
Infants were born full-
term from
uncomplicated
pregnancies, had a birth
weight of at least 2.268
kg, had no chronic or
acute medical
conditions and between
4 months and zero day
to 4 months and 29 days
- The Alberta Infant
Motor Scale at 4
months of age
- Assessed general
motor development
- Position log: amount of time per
day on belly, back, seated, held or
other positions in hour increments
- Parent questionnaire: infant date
of birth, birth weight, race, gender,
current weight, length, number of
weeks of the pregnancy, general
information of the infant’s health
- None of the demographic factors
were predictive of infant’s ability to
achieve motor milestones. Prone
awake time, however, was predictive
of achieving 7 of 21 prone, 3 of 9
supine and 3 of 12 sitting milestones.
- With increasing difficulty of
milestone, greater percentage of
infants achieving the milestone had
increased prone awake time
38
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
old.
Espel et al.,
201465
Prospective
cohort study
A sample of 232
mother-baby dyads
were enrolled. Infants
were full-term,
singleton births.
Women were eligible if
they were less than 16
weeks pregnant, English
speaking, non-smokers,
over 18 years of age,
not taking steroidal
medication with no
evidence of alcohol or
drug use during
pregnancy
- Bayley Scales of
Infant Development,
2nd edition at 3, 6 and
12 months
postpartum
- Assessed general
motor development
- Birth outcomes: gestational age
at birth, parity, birth weight, Apgar
scores, past maternal health and
pregnancy related or birth
complications
- Potential confounders:
Race/ethnicity, cohabitation status,
maternal education, household
income, obstetrical risk, birth
order, birth weight and infant sex
- Gestational length
- Term status (early term=37-38
weeks, term=39-40 weeks, later
term=41 weeks, post-
term=41+weeks)
- Among infants born full-term (39-
40 weeks’ gestation) longer gestation
associated with higher mental and
motor development at 3, 6 and 12
months postpartum
- term infants score lower than late
term infants on mental development
at 3 months and motor development
at 12 months
- Early term infants scored lower than
term and late term on mental
development at 3 month, on both
mental and motor development at 6
months and on motor development at
12 months
Fanaroff et
al., 200666
Prospective
cohort study
A sample of 156 infants
with extremely low
birth weight (<1000
grams) were enrolled).
Bayley Scales of
Infant Development,
1st edition at 2 years
of age
- Assessed general
motor development
- Hypotension status
- Cerebral palsy diagnosis
- audiologic testing
- Symptomatic hypotension was
associated with lower psychomotor
development score, but not mental
development scores
- Adjusted models described an
association between delayed motor
development and hearing loss
Fetters &
Huang,
200767
Prospective
cohort study
A sample of 30 preterm
infants born very-low-
birth weight with white
- Alberta Infant
Motor Scales at 1, 5
and 9 months of age
- White matter disease:
periventricular white matter
lesions or severe hemorrhage
- Sleeping prone, even if not
exclusively, was positively associated
with motor development at 1, 5 and 9
39
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
matter disease, 21
preterm infants born
very-low-birth weight
without white matter
disease, and 17 term
infants. Preterm infants
were eligible if they
were born between 24-
31 weeks’ gestation.
- Assessed general
motor development
- Sex, race, gestational age
- Term status
- Sleeping, feeding and playing
position
months
- Prone sleeping preterm infants had
high motor scores only at 9 months
compared to the preterm infants with
white matter disease
- At one month, only prone sleeping
was associated with motor
development. At 5 months, sleeping
prone, playing prone and group
membership were associated with
motor development. At 9 months,
sitting for play and group
membership were associated with
motor development. Sitting for play
was negatively associated with motor
development.
Gilbert et
al., 201368
Cross-
sectional
study
A sample of 16595
children from the Child
Health Improvement
through Computer
Automation (CHICA)
system.
- Adapted questions
from the Denver
Developmental
Screening Test II
prior to 72 months of
age.
- Intimate partner violence
- Parental psychological distress:
adapted from the Patient Health
Questionnaire-2 and the
Edinburgh Postnatal Depression
Scale
- Child abuse concern
- Sociodemographic
characteristics: gender,
race/ethnicity, clinic, insurance
type, preferred language
- Parental report of both intimate
partner violence and parental
psychological distress was associated
with failure of at least one milestone
question in language, personal-social
and gross motor
- Intimate partner violence was
associated with poor language,
personal-social and fine motor
development
- Parental psychological distress was
associated with poor language,
personal-social, gross and fine motor
development
Hediger et
al., 200269
Cross-
sectional
study
A sample of 4621 US-
born singleton infants
between the ages of 2-
47 months were
enrolled.
- Derived from
Bayley Scales of
Infants Development,
the Gesell scale and
the Denver
Developmental
Screening Test
- Birth weight and gestation age
- Infant race/ethnicity, sex,
maternal parity, plurality, birth
order
- Muscularity: mid-upper arm
circumference, triceps skinfold
thickness,
- Univariate analysis suggested
significantly lower scores among the
following: Mexican-Americans and
“other race/ethnicity” compared to
non-Hispanic white, less than 11
years’ education, maternal age of 35
years or greater, child is male, child
40
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
between 2-47 months
- Assessed general
motor development
(motor and social
development
variable)
- Sociodemographic: type of
residency (metropolitan vs. non-
metropolitan), region of residence,
maternal age, maternal smoking,
education
was not first born, low birth weight
(<2500 grams) and less than 36
weeks’ gestation
- Multiple regression models: Lower
scores associated with higher birth
order, less than 11 years’ education,
maternal age of 35 years or greater,
preterm low birth weight and term
low birther weight. Higher scores
were associated with non-Hispanic
black and maternal age less than 19
years. Analysis stratified by sex.
- Age trends by sex: males reported
higher scores at age 2-3 months, but
scores were similar through the
remainder of the first year. Females
exhibited higher scores after the first
year.
Hinkle et
al., 201270
Prospective
cohort study
A sample of 6850
infants were selected
from the Early
Childhood Longitudinal
Study – Birth Cohort.
Analysis was limited to
singleton infants,
without major structural
or genetic congenital
anomalies.
- Bayley Scales of
Infant Development,
2nd edition at 20-38
months of age
- Assessed general
motor development
- Maternal pre-pregnancy BMI
- Additional variables: maternal
age, race/ethnicity, parity, marital
status, education, smoking during
last trimester of pregnancy,
diabetes before or during
pregnancy, chronic or gestational
hypertension, child’s sex,
gestational age, birth weight,
household income, number of
residents in household, gestational
weight gain, breastfeeding,
- Mental development scores were
lower among children of pre-pregnant
obese class II and III mothers,
compared to children of pre-pregnant
normal BMI mothers
- The risk of delayed mental
development was increased among
children born to underweight or
severely obese mothers than among
those born to normal weight mothers
- Psychomotor development did not
vary according to pre-pregnancy BMI
status of mothers
- Significant differences were
observed in mean mental and motor
scores for the following: maternal
ethnicity, maternal marital status
(lower if unmarried), maternal
education, maternal parity (lower if
41
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
multiparous), maternal prenatal
smoking (lower if smoking),
household poverty and child’s sex
(lower if male)
- Mental development scores were
significantly different among
maternal age, and maternal
prepregnancy BMI
Huizink et
al., 200371
Prospective
cohort study
A sample of 170
nulliparous women
were recruited through
pregnancy. Pregnancies
were singleton,
uncomplicated, good
baby health. Women
spoke fluent Dutch, did
not use drugs or
medication.
- Bayley Scales of
Infant Development,
1st edition at 3 and 8
months of age
- Assessed general
motor development
- Everyday Problem List
- Pregnancy Related Anxieties
Questionnaire-Revised
- Salivary cortisol
- Edinburgh Postnatal Depression
Scale
- Confounders: education,
professional level of women and
partner, tobacco and alcohol use,
biomedical risk factors during
pregnancy (cumulative score)
- Perinatal covariates: birth
weight, gestational age, delivery
complications (cumulative score)
- Postnatal covariate:
breastfeeding, psychological well-
being, perceived stress
- Mental development at 3 and 8
months significantly correlated.
Motor development at 3 and 8
months also significantly correlated
- A high amount of daily hassles
early in pregnancy, or a strong fear of
giving birth in late pregnancy was
associated with lower mental
development scores at 8 months
- A strong fear of giving birth mid-
pregnancy was associated with low
mental and motor development at 8
months
- High cortisol levels during late
pregnancy was related to low mental
development scores at 3 months and
low motor scores at both 3 and 8
months
Jacobson et
al., 199372
Prospective
cohort study
A sample of 382 Black
13-month-old infants
were recruited. Infants
had birth weight above
>1500 grams,
gestational age greater
than 32 weeks, no major
chromosomal anomalies
or neural tube defects or
multiple births.
- Bayley Scales of
Infant Development,
2nd edition at 6, 12
and 24 months of age
- Assessed general
motor development
- Alcohol and drug use (cocaine,
marijuana, opiates, depressants,
stimulants) during pregnancy
- Peabody Picture Vocabulary Test
- Home Observation for
Measurement of the Environment
(HOME Inventory)
- Beck Depression Inventory
- Control variables: maternal age,
education, marital status, welfare
status, parity, infant sex, smoking
- Maternal alcohol consumption
during pregnancy was associated with
lower mental development and
McCall index scores.
- Motor development was reduced
when maternal alcohol consumption
was reported at highest levels
(2oz/day during pregnancy; 4oz/day
at conception)
- Infants whose mother drank
0.5oz/day of alcohol were twice as
42
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
during pregnancy, number of
prenatal visits, quality of prenatal
visits
likely to score in the bottom 10th
percentile of mental development
scores
- Infants whose mother drank
2.0oz/day of alcohol were five times
as likely to score in the bottom 10th
percentile of motor development
scores
Janssen et
al., 201173
Prospective
cohort study
A sample of 348 infants
with gestational age <32
weeks were recruited.
- Bayley Scales of
Infant Development,
1st edition at 13
months of age
- Assessed general
motor development
- Gross Motor
Function
Classification System
(identify subgroup
with cerebral palsy)
- Infant factors: sex, gestational
age, birth weight, neonatal
convulsion, retinopathy of
prematurity, necrotizing
enterocolitis, interventricular
hemorrhage, periventricular
leukomalacia, chronic lung disease
- Growth variables: height, weight,
head circumference
- Parent factors: maternal
education
- Motor develop of preterm infants
from 6-24 months was unstable
- Motor development was influenced
by male sex, height, intraventricular
hemorrhage and motor quality
- The influence of maternal education
varied at different time points
43
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Johnson et
al., 201274
Prospective
cohort study
A sample of 309
mother-infant dyads
were recruited. Mothers
were exposed to either
antidepressants or
antipsychotics, but not
antiepileptics. Mothers
also had no history of
substance abuse prior to
6 months of conception.
- Infant Neurological
International Battery
at 4-18 months of age
- Assessed general
motor development
- Habituation paradigm: infants’
fixation time on stimulus decrease
by 50% compared to previous
trials
- Structured clinical interview:
determine current and lifetime
psychiatric diagnoses
- Beck Depression Inventory
- Non-associated variables:
neurological test: gestational age,
delivery complications, birth
weight, sex, maternal education,
number of children at home,
bipolar/anxiety disorder, number
of mood episodes, number of
psychotic symptoms, duration of
disorder, number of
hospitalizations, leave of absence
due to mental illness, current
treatment status, previous therapy,
concomitant prenatal exposure to
anxiolytic and hypnotics
- Covariates significantly related to
Infant Neurological International
Battery score: infant age, maternal
age, marital status, lifetime history of
at least 1 depressive episode or
dysthymia, lifetime diagnosis of
psychotic disorder, severity index
- Maternal age was positively
associated with habituation, whereas
breastfeeding was associated with
habituation in fewer trial. Number of
months depressed during pregnancy
was also associated with longer
habituation times.
- Postnatal exposure via lactation to
antipsychotics associated with lower
neurological test scores.
Antidepressant exposure failed to
predict scores.
- Infants with antipsychotic exposure
had significantly lower neurological
score than antidepressant exposed or
unexposed infants. Unexposed infants
did not differ from antidepressant
exposed infants.
- No significant effects of prenatal
medication exposure on habituation
tasks were revealed
44
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Julvez et
al., 200975
Prospective
cohort study
A subset of 420 children
from the Menorca
cohort study were
assessed.
- McCarthy Scales of
Children’s Ability
adapted in Spanish at
4 years of age
- Assessed general
motor development
- Current use of prescribed or
over-the-counter medications or
supplements (including folate,
vitamins, calcium, iron
supplements)
- California Preschool Social
Competence Scale
- Attention-deficit hyperactivity
disorder criteria from DSM-IV (by
two neuropsychologists)
- Additional covariates: parental
education, SES, marital status,
maternal health, obstetric history
(pregnancy complications, type of
delivery) parity, alcohol and
tobacco use during
pregnancy/child exposure to
smoke, paternal smoking
- Infant variables: Gestational age
and birth anthropometric
measurements
- Semi-quantitative food frequency
instrument: dietary intake during
pregnancy
- Folic acid supplementation was
associated with verbal, motor and
verbal executive functions, social
competence and inattention
symptoms when adjusting for SES,
education, parity, marital status,
smoking during pregnancy, calcium
and iron supplementation, sex,
duration of breastfeeding, child’s age,
season of neurological assessment
and area of residency
- Maternal iron and calcium
supplement use at the end of the first
trimester of pregnancy was not
associated with any
neurodevelopmental outcomes
- Social class, education, location,
parity, smoking during pregnancy
and duration of breastfeeding were
associated with folic acid
supplementation
Kanazawa
et al.,
201476
Prospective
cohort study
A sample of 37 preterm
infants were recruited.
Infants had gestational
ages of no later than 36
weeks and had no
congenital
malformations,
chromosomal
anomalies,
periventricular
hemorrhage, severe
respiratory failure, or
- Pediatric Evaluation
of Disability
Inventory at 18
months of age.
- Alberta Infant
Motor Scale at 18
months of age.
- Both assessed
general motor
development
- Muscle and subcutaneous
thickness: measured using real-
time ultrasound imaging
- Significant correlations between
Pediatric Evaluation of Disability
Inventory and subcutaneous fat
thickness. No correlation with
muscles thickness found.
- Motor delay group had significantly
lower subcutaneous fat thickness
values at 3 and 18 months of age, and
lower weight at 3 and 6 months of
age, and lower BMI at 3 months of
age.
- Using logistic regression only
45
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
necrotizing
enterocolitis.
subcutaneous fat thickness was a
significant predictor of motor delays
Kaplan-
Estrin et
al., 199977
Prospective
cohort study
A sample of 92
economically
disadvantaged, African
American, 26-month
old toddlers were
recruited.
- Bayley Scales of
Infant Development,
1st edition at 13 and
26 months at age
- Assessed general
motor development
- Alcohol and drug use protocol:
interviews at each prenatal visit
begin at 13 weeks’ gestation and at
13 months postpartum. Data
collected for opiates (heroin,
methadone, codeine), cocaine,
marijuana, depressants and
stimulants. Urine screen at 1st
prenatal visit.
- Three language development
measures: 1) Communication
Development Inventory – Words:
Short form, 2) the Noncanonical
Commands test, and 3) the Early
Language Milestone Scale
- Control variables: maternal age,
education, marital status, welfare
status, gravidity, parity, sex,
smoking during pregnancy, illicit
drug use, number of prenatal
visits, indicator of quality of
prenatal care
- Peabody Picture Vocabulary
Test-Revised
- HOME Inventory
- Beck Depression Inventory
- Current Maternal Drinking
- At 13 and 26 months of age,
maternal drinking associated with
lower mental and motor development
scores. At 13 months, maternal
drinking at conception was associated
with mental and motor development,
whereas drinking during pregnancy
was only associated with mental
development.
- Drinking during pregnancy was not
associated with language scores.
Drinking postpartum, however, was
related to language intelligibility
46
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Kato et al.,
201678
Retrospective
cohort study
A sample of 104 very-
low-birth weight infants
were recruited.
- Kyoto Scale of
Psychological
Development at 3
years of age
- Assessed general
motor development
(postural-motor)
- Gestational age: <28 weeks or
>28 weeks
- Infant growth: appropriate-for-
gestational age, small-for-
gestational age, severely small-for-
gestational age
- Transfontanellar ultrasound
examinations for first 5 days
postpartum
- Brain magnetic resonance
imaging at discharge from NICU
- Electroencephalography (EEG)
- Other variables: Maternal
smoking and drinking, neonatal
diseases (respiratory distress
syndrome, infections, retinopathy
of prematurity, chronic lung
disease, intracranial hemorrhage,
periventricular leukomalacia,
necrotizing enterocolitis,
meconium disease
- Among infants >28 weeks’
gestation, no differences were
reported in developmental quotient
between severely small-for-
gestational age and appropriate-for-
gestational age. However, among
extremely premature infants,
differences in postural-motor
development were reported severely
small-for-gestational age and
appropriate-for-gestational age
- Gestation age, birth weight, birth
length and birth head circumference
were all significantly lower in infants
with delays in postural motor
development. Longer duration of
mechanical ventilation was also
associated with postural-motor delays
47
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Larroque et
al., 199579
Prospective
cohort study
A sample of 155
mother-child dyads
were recruited. Mothers
were from the Roubaix,
France region and had
singleton pregnancies.
- McCarthy Scales of
Children’s Abilities at
4.5 years of age
- Assessed general
motor development
- Alcohol consumption: prior to
pregnancy and first trimester
- Home Observation for the
Measurement of the Environment
Scale
- Covariates measured: child’s
health, sleep or feeding disorders,
problems at school, life events,
sociodemographic characteristics,
tobacco consumption during
pregnancy, birth weight
- Covariates included in the
model: birth order, maternal
education, maternal employment,
family status, score of family
stimulation, gender, age, and
examiner
- Crude analysis showed a significant
relationship between alcohol
consumption during pregnancy and
general cognitive index, verbal,
performance and quantitative scale
scores
- Scores on the memory or motor
scales were not related to alcohol
consumption during pregnancy
- Poor general cognitive index was
associated with decreased education,
no maternal occupation, single
family, higher birth order, low family
stimulation, and cigarette
consumption during pregnancy
- After controlling for confounders,
mean general cognitive index was
lower among children of heavy
drinking mothers compared to light
drinking mothers
Little et al.,
200280
Prospective
cohort study
A subset of 915 toddlers
were assessed from the
Avon Longitudinal
Study of Parents and
Children.
- Griffiths Scale of
Mental Development
at 18 months of age
- Assessed general
motor development
- Alcohol use during pregnancy
- Breastfeeding practices
- Alcohol exposure via breastmilk
- Potential confounders:
postpartum smoking, marijuana
exposure, caffeine exposure, 32-
week food frequency, parity,
employment at 32 weeks’
gestation, housing situation,
marital status
- Locomotor development scores
were higher among white infants than
infants of other ethnicities
- No significant effect of alcohol
exposure via breastmilk on locomotor
development
48
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Mazer et
al., 201081
Prospective
cohort study
A sample of 117
children with congenital
anomalies were
enrolled.
- Bayley Scales of
Infant Development,
1st edition in Dutch at
6, 12 and 24 months
of age
> Assessed general
motor development
- Movement
Assessment Battery
for Children at age 5
years
> Assesse general
motor development
- Demographic and medical
information: ethnicity, SES, type
of congenital anomalies, total
number of major and minor
anomalies, total days spent in
hospital in their first 6 months,
number of medical appliances at
discharge, number of surgical
interventions and number of
additional medical problems in the
first 24 months
- Revised Amsterdam Children’s
Intelligence Test- short version
- Predictors of IQ at 5 years:
- 6 months: Protective: High SES,
mental development on Bayley//Risk:
Non-Dutch, number of congenital
anomalies
- 12 months: Protective: High
SES, mental development on
Bayley//Risk: Non-Dutch, number of
congenital anomalies
- 24 months: Protective: mental
development on Bayley//Risk:
number of congenital anomalies
- Predictors of motor development at
5 years:
- 6 months: Protective:
psychomotor development on
Bayley//Risk: Non-Dutch
- 9 months: Protective:
psychomotor development on Bayley
- 12 months: psychomotor
development on Bayley//Risk:
medium SES
Messinger
et al.,
200482
Prospective
cohort study
A subset of 1227
mother-children dyads
were assessed from the
Maternal Lifestyle
Study. Mothers were 18
years or older, without
psychiatric
disorders/developmental
delays or language
barriers. Infants were
inborn, likely to
survive, singleton,
gestational age <43
weeks.
- Bayley Scales of
Infant Development,
2nd edition at 12, 24,
36 months of age.
- Assessed general
motor development
- Maternal Interview of Substance
Use/Meconium metabolite
benzoylecgonine
>Main exposure=cocaine and
opiates
> Alcohol, tobacco and
marijuana included as covariates
- Additional covariates: maternal
education, SES (Hollingshead
Index of Social Position Score),
poverty status, maternal care vs
other care
- Home Observation for
Measurement of the Environment
- Significant differences between
infants exposed to cocaine and not
exposed to cocaine were reported for
mental development at 1 and 3 years
of age and overall mental
development. No differences were
observed for motor development.
- Significant differences between
infants exposed to opiates and not
exposed to opiates were reported for
mental development at 1 year, motor
development at 2 and 3 years, overall
motor development, and behavioral
ratings at 2 years of age.
49
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
(HOME) Inventory
- Peabody Picture Vocabulary
Test-Revised
- Brief Symptom Inventory from
the Global Severity Index of
psychological symptoms
-Behavioral Rating Scale
- After controlling for covariates,
neither cocaine nor opiates were
associated with mental development
scores
- After controlling for covariates,
neither cocaine nor opiates were
associated with psychomotor
development scores
- After controlling for covariates,
neither cocaine nor opiates were
associated with behavioral rating
scores
- Low birth weight was associated
with low mental, motor and
behaviour scores
- Higher quality of caregiving was
associated with higher mental and
motor development scores
- Higher HOME scores were
associated with higher psychomotor
and behavior scores
- Consistent presence of the mother in
the household was associated with
higher mental and psychomotor
scores
Mellins et
al., 199483
Cross-
sectional
study
A sample of 77 infants
were recruited. Among
those recruited, 24
infants were HIV-
positive, 30
seroreverters, and 23
non-infected infants
born to mothers without
HIV.
- Bayley Scales of
Infant Development,
1st edition at 4-30
months of age
- Assessed general
motor development
- HIV-status
- Prenatal drug exposure
- Infants exposed to HIV and prenatal
drugs had an increased risk of poor
mental and motor development
compared to infants with either HIV
infections or prenatal drug exposure
- Drug exposure and neurological
dysfunction were risk factors for
mental development using multiple
regression
- Neurological dysfunction was a
significant predictor of psychomotor
development
50
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
- No significant effect on mental or
motor development and sex or
ethnicity
Mendez et
al., 200884
Prospective
birth cohort
A sample of 392 full-
term children and their
mothers were enrolled.
- McCarthy Scales of
Children’s Abilities
test at 4 years of age.
- Assessed general
motor development
- Seafood consumption: semi-
quantitative, interviewer-
administered questionnaire.
>interested in DHA content
- Covariates: maternal education,
parity, sex, birth weight, weeks’
gestation, breast-feeding duration,
child age at testing, examiner
- Among children breastfed for <6
months, maternal fish intakes of >2-3
times/week remained associated with
significantly higher mean scores
across all subscales
- Maternal intakes of other types of
seafood during pregnancy were
associated with lower general
cognitive, perceptual-performance,
verbal and numeric scores at 4 years
of age
- Child intake of fish and other types
of seafood was not associated with
test scores
Miller-
Loncar et
al., 200485
Prospective
cohort study
A subset of 392 cocaine
exposed and 776
unexposed infants from
the Maternal Lifestyle
Study were assessed.
- NICU Network
Neurobehavioral
Scale (NNNS) at 1
month of age
> Assessed general
motor development
(combined composite
score)
- Posture and Fine
Motor Assessment of
Infants (PFMAI) at 4
months of age
> Assessed
postural and fine
motor development
(combined into
composite score)
- Bayley Scales of
- Maternal Inventory of Substance
Abuse (timing and amount of
cocaine, alcohol, nicotine, and
marijuana used during pregnancy
- Hollingshead Index of Social
Position
- Covariates: SES, birth weight,
race, study site
- Prenatal cocaine exposure was
significantly associated with poorer
motor skills.
- Prenatal cocaine exposure interacted
with age, where infants exposed to
cocaine displayed a faster rate of
increase in motor skills than the
comparison group
- Study site, birth weight and heavy
tobacco use was also associated with
motor development
- Heavy prenatal exposure to cocaine
was associated with poorer motor
scores compared to unexposed
infants. There was not a significant
difference based on level of exposure
for change over time, however.
51
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Infant Development,
2nd edition at 12
months of age
> Assessed general
motor development
- Peabody
Developmental Motor
Scales at 18 months
of age
> Assessed general
motor development
(combined into
composite score)
Minguez-
Milio et al.,
201186
Prospective
cohort study
A sample of 138
extremely-low-birth
weight infants were
recruited. Of those
recruited, 73 were born
via C-section and 65
were born vaginally.
- McCarthy Scales of
Children’s Abilities at
61.18 months of age
- Assessed general
motor development
- Clinical records: maternal age,
parity, previous miscarriages,
previous history of preterm
delivery, gestational age,
- Pregnancy features: the presence
of threatened abortion, urine
infections, maternal anemia, pre-
eclampsia, intrauterine growth
restrictions, hydramnios,
oligoamnios, premature rupture of
membranes, cervical
incompetence
- Delivery: presentation, route of
delivery
- Newborns: birth weight, Apgar
scores, gestational age, sex,
umbilical cord blood gases, type of
reanimation used
- Neonatal morbidity: respiratory
distress syndrome, periventricular
hemorrhage, bronchopulmonary
dysplasia, periventricular
- 29.1% of children exhibited
developmental delays. Among those
children 27% exhibited motor delays.
- Route of delivery and sex were not
found to be associated with
development scores
52
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
leukomalacia, retinopathy of
prematurity, sepsis, seizures,
necrotizing enterocolitis,
pneumothorax, pneumonia, patent
ductus arteriosus, apnea,
meningitis, transitory RDS,
hemodynamic shock
- Procedures carried out on
newborn
Mulligan et
al., 199887
Prospective
cohort study
A sample of 48 full-
term infants were
recruited from an
ongoing longitudinal
study. Infants were free
of chronic disease that
may interfere with
growth.
- Bayley Scales of
Infant Development,
1st edition at 6, 9 and
12 months of age
- Assessed general
motor development
- Children’s Activity Rating Scale
- Centre Activity Evaluation:
caregiver ratio, whether infants
spent time in gross motor room,
level that the infants were
encouraged to interact with
caregivers and environment, use of
infant equipment, number of
square feet per infant
- Percent body fat: dual energy x-
ray absorptiometry (DXA)
- Child’s weight
- At 6 months of age, psychomotor
development was not associated with
any center characteristics
- At 9 months of age, psychomotor
development was lower among
infants in centers with
infant:caregiver ratios of 5:1
compared to ratios of 3:1 or 4:1
- At 12 months of age, the use of
infant equipment was not associated
with motor development
Nakajima
et al.,
200688
Prospective
cohort study
A sample of 134
mother-child dyads
were recruited into the
Hokkaido Study on
Environment and
Children’s Health). All
subjects were native
Japanese and residents
of Sapporo and
surrounding areas.
- Bayley Scales of
Infants Development,
2nd edition at 6
months of age
- Assessed general
motor development
- Blood sample during second
trimester
- Questionnaire of home
environment
- Polychlorinated dibenzo-p-dioxin
(PCDD) isomer 1,2,3,4,6,7,8-
HpCDD, total PCDDs and total
PCDDs/PCDFs (polychlorinated
dibenzofurans) were negatively
associated with mental development
- PCDD isomers 1,2,3,7,8,9-HxCDD,
1,2,3,4,6,7,8-HpCDD, 2,3,7,8-TCDF,
1,2,3,7,8-PeCDF, and PCDF isomer
1,2,3,6,7,8-HxCDF were all
negatively associated with
psychomotor development
***NOTE: This is an analysis of
polychlorinated biphenyls (PCBs)
and dioxins, persistent environmental
pollutants***
53
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Nash et al.,
201189
Retrospective
cohort study
A sample of 289 very-
low-brithweight preterm
infants were recruited.
Infants were excluded if
they had a serious
congenital anomaly or
depression at birth, were
small-for-gestational
age, or died during
initial hospitalization.
- Bayley Scales of
Infant Development,
3rd edition at 18-24
months of age
- Assessed general
motor development
(composite score)
- Infant characteristics: gestational
age, sex, multiple birth status,
inborn/outborn status, necrotizing
enterocolitis, patent ductus
arteriosus, nosocomial infection,
intraventricular hemorrhage,
chronic lung disease,
dexamethasone use
- Growth assessment: weight,
length, head circumference
- Males and females had similar
cognitive and motor composite
scores, however, males had lower
language scores than females
- Using WHO growth standards,
children with a decelerated pattern of
weight gain had lower cognitive,
language and motor scores compared
to infants with sustained weight gain
- No association was found using
CDC reference growth charts
Nelson et
al., 200490
Prospective
cohort study
A sample of 143 2-year
old and 274 4-year old
children were enrolled.
- Bayley Scales of
Infant Development,
1st edition at 2 years
of age
>Assessed general
motor development
- Peabody
Developmental Motor
Scales at 4 years of
age
> Assessed fine
and gross motor
- Cocaine, marijuana, tobacco,
alcohol exposure
- Peabody Picture Vocabulary
Test-Revised
- Brief Symptom Inventory/Global
severity Index
- Maternal characteristics: race,
age, SES, gravida, parity, number
of prenatal care visits
- Infant Measures: birth outcomes,
Apgar scores, Hobel Neonatal
Risk Index
- Hematologic assessment:
hemoglobin, mean corpuscular
volume, transferrin saturation,
serum ferritin, lead, iron status
- Environmental measures: Home
Observation of the Environment
(HOME) Inventory
Neurodevelopment: Wechsler
Preschool and Primary Scales of
Intelligence
- Correlations with motor
development:
- 2-year psychomotor: ethnicity,
parity, maternal education, sex
- 4-year gross motor: parity,
maternal IQ (PPVT-R), birth weight,
head circumference, Hobel risk score,
gestational age
- 4-year fine motor: parity,
maternal education, sex, nonmaternal
care
- Full Scale IQ was predicted by iron
deficiency anemia and lead levels
- Verbal IQ was predicted by HOME
scores
- Performance IQ was predicted by
maternal IQ, cocaine exposure and
lead
Ohman et
al., 200991
Prospective
cohort study
A sample of 82 infants
with congenital
muscular torticollis and
40 healthy control
- Alberta Infant
Motor Scales (AIMS)
at 2, 6 or 10 months
of age
- Physiotherapist treatment
- Infants gestation age, weight and
length at birth
- Sleep and awake position
- At 2 and 6 months of infants with
congenital muscular torticollis scores
significantly lower on motor scores
than the healthy control infants
54
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
infants were enrolled.
Infants were aged either
2, 6 or 10 months of
age, were born >37
weeks’ gestation and
had no suspected
syndromes or medical
conditions.
- Assessed general
motor development
- Infants who spent at least 3 three
times daily prone when awake had
significantly higher AIMS scores
then those who spent less time in
prone at 2, 6 and 10 months of age
- Gestational age, sex, birth weight,
birth length, and plagiocephaly had
no significant effect on AIMS scores
Polanska et
al., 201592
Prospective
cohort study
A subset of 538 mother-
child dyads from the
Polish Mother and
Child Cohort Study
were assessed.
Pregnancies were
singleton, unassisted
conception,
uncomplicated and
mother had no chronic
diseases.
- Bayley Scales of
Infant and Toddler
Development at 12
and 24 months of age
- Assessed general
motor development
- Smoking history via interview
and salivary cotinine levels
- Alcohol consumption via
questionnaire
- Leisure-time physical activity at
three point during pregnancy and
metabolic equivalent value was
assigned to each activity
- Pre-pregnancy BMI
- Folic acid supplementation
before and during pregnancy
- Confounding variables: sex,
parental age, education, SES,
marital status, major pregnancy
complications
(diabetes/hypertension/intrahepatic
cholestasis), type of delivery,
gestational age, biometric
indicators of birth, breastfeeding,
number of siblings, day care
attendance
- Cotinine levels were negatively
associated with motor and cognitive
development at 24 months of age in
adjusted models
- Children of underweight women
had lower language and cognitive
scores at 1 year of age and lower
motor scores at 2 years of age
compared to children of normal
weight women
- Recommended leisure activity in
the first, second and third trimesters
was associated with higher language
development at 2 years
- Prenatal exposure to tobacco was
associated with low motor
development at 1 and 2 years of age,
underweight pre-pregnancy was
associated with language abilities at 1
year of age and recommended level
of physical activity had a positive
impact on language development at 2
years in the final multivariable model
with inclusion of all lifestyle factors
and confounders
Ratliff-
Schaub et
Prospective
cohort study
A sample of 213 infants
from the Collaborative
- Bayley Scales of
Infant Development,
- Sleep position
- Parenting Stress Index subscale
- Race and alcohol consumption
during pregnancy were associated
55
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
al., 200193 Home Infant
Monitoring Evaluation.
Infants were <1750
grams and < 34 weeks’
gestation.
2nd edition at 44, 56
and 92 weeks of age
- Assessed general
motor development
- Confounders: race, marital status,
maternal age, education, smoking
or alcohol consumption during
pregnancy, parity, family got
along, days in hospital,
methylxanthine use, sex, birth
weight, head circumference,
supplemental 02 use
with sleep positive in bivariate
analysis
- Significant difference between
motor skill item and sleep position:
holds head in midline position,
maintains head at 45o and lowers with
control, maintains head at 90o and
lowers with control
- Psychomotor and mental
development scores did not differ
between prone and supine sleepers in
either the unadjusted or adjusted
analyses at 56 or 92 weeks of age
Ravenscroft
et al.,
200794
Cross-
sectional
study
A sample of 412
Canadian infants born at
term, weighing >2500
grams and no history of
prenatal, perinatal or
postnatal medical
complications or
maternal complication
were enrolled.
- Harris Infant
Neuromotor Test
(HINT) at 3-12
months of age
- Assessed general
motor development
***NOTE: lower
score indicates better
development***
- Maternal education level
- Infant age
- Bivariate analysis: Highly negative
correlation between infant age and
HINT scores (indicates improving
development with age), weak positive
relationship between maternal
education and HINT score
- No effect of maternal age and HINT
scores when controlling for infant age
Richardson
et al.,
200895
Prospective
cohort study
A sample of 320 women
were enrolled into the
study.
- Bayley Scales of
Infant Development,
2nd edition at 1 year
of age
- Assessed general
motor development
- Use of cocaine, crack, tobacco,
marijuana, alcohol or other illicit
substances prior to pregnancy or
during first trimester
- Infant: length, weight, head
circumference, age, growth at 1-
year postpartum, medical history
- Infant Behaviour Record
- Mothers: substance use,
demographic characteristics, social
support, household composition,
psychological characteristics
- Centre for Epidemiological
- Bivariate analyses: Infants exposed
to cocaine in the first trimester has
lower gestational age, lower birth
weight, more likely to be born
prematurely, have lower psychomotor
score and rated as more
fussy/difficult and unadaptable than
were the infants were not exposed.
- There were no effect of prenatal
cocaine/crack use on weight, height
or head circumference at 1 year
- Significant predictors of growth
were: age, male, maternal height.
56
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Studies – Depression Scale
-Spielberger State-Trait Anxiety
Inventory
- Bates Infant Characteristics
Questionnaire
- PROCESS scale: assess home
environment
Decreased growth predictors were:
maternal depression, prenatal tobacco
and alcohol use.
- There were no effect of prenatal
cocaine/crack use on mental
development
- Significant predictors of mental
development were: higher PROCESS
scores, Caucasian, examiner.
Predictors of lower scores were: older
age, more children in the household,
presence of a male in the household,
prenatal alcohol use
- Second trimester cocaine/crack use
was a significant predictor of
psychomotor development. Lower
score was predicted by older age at
assessment, prenatal alcohol
exposure, more children in the
household
- Cocaine exposure during 1st and 2nd
trimester were predictors of
unadaptable factor of the Bates ICQ
Scale. Moreover, cocaine use during
the 2nd and 3rd trimester predicted
increased fussiness/difficultness
- Additional predictors of difficult or
unadaptable temperament scores
were: younger age, lower maternal
education, more hospitalization,
maternal depression, more children in
the household, third trimester
marijuana exposure, and higher levels
of current maternal substance use
- Less difficult temperament was
predicted by the presence of a male in
the house, and more developmental
57
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
stimulation in the home
Ronfani et
al., 201596
Prospective
cohort study
A subset of 900 women
were assessed from the
PHIME project (Public
health impact of long-
term, low-level, mixed
element exposure in
susceptible population
strata).
- Bayley Scales of
Infant Development,
3rd edition at 18
months of age
- Assessed general
motor development
- Standard Progressive Matrices
(SPM): maternal IQ
- Appraisal of Indicators through
Research and Evaluation:
assessment of home environment
- Socioeconomic Status Index
- Potential explanatory variables:
sex, birth weight, gestational age,
maternal age at delivery, BMI
before pregnancy, maternal
mercury exposure (hair and
venous blood samples), house
surface, mother living with
partner, other children living in the
house, maternal smoke, alcohol
intake during pregnancy, dental
visits, dental works, exclusivity of
breastfeeding at 4 months, daycare
attendance
- Only “promotion of autonomy” on
the AIRE scale was independently
associated with cognitive score
- Mediation analysis showed a
direct effect of SES on cognitive
development and a mediation effect
on the promotion of autonomy
- Multivariable analysis revealed
maternal IQ and promotion of
autonomy are independently related
to language development
- Mediation analysis showed a
direct effect of maternal IQ on
language development and a
mediation effect of SES on this
relation
- A direct effect of SES and a
mediation by promotion of autonomy
was also observed
- Multivariable analysis revealed
maternal IQ and promotion of
autonomy are independently related
to motor development
- Mediation analysis showed a
direct effect of maternal IQ on motor
development and this relation is
mediated by promotion of autonomy
58
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Sansavini
et al.,
199697
Prospective
cohort study
A sample of 250 healthy
Italian preterm infants
were enrolled. An
additional 35 healthy
full-term infants were
enrolled and matched
for age, sex, and
socioeconomic status.
- Brunet-Lezine Test
(Italian) administered
at 6, 12 and 24
months postpartum
- Assessed general
motor development
- Standord-Binet Intelligence test
- Medical information: Apgar
score, neonatal complications
- Biological risks: birth weight,
intra-uterine growth retardation,
sec
- Social risks: maternal and
paternal education
- Preterms present delays in
developmental quotients, motor, eye-
hand coordination, language and
social behaviour development
- Biological risks were associated
with global and specific development
(except language) at 6,12 and 24
months of age. Moreover, intra-
uterine growth retardation was
associated to global development at 5
years of age.
- Paternal education was related to
cognitive development at 12 months,
linguistic and global development at
24 months and global development at
4 and 5 years
- Maternal education was related to
cognitive and global development at
12 months, and linguistic
development at 24 months
Santos &
Costa,
201598
Cross-
sectional
study
A sample of 109
Portuguese families
were enrolled. The
infants were aged 6-22
months and free from
existing disease. Parents
were literate.
- Scale of
Psychomotor
Development in Early
Childhood
- Sociodemographic data: age,
gender, marital status, years of
education, professional status,
physical and psychological
diseases, medical or psychological
treatment, number of pregnancies,
number of miscarriages, number
of children, age of children,
children’s physical and
psychological diseases
- Clinical data: pregnancy
planning, prenatal care, risk
pregnancy, gestational age, type of
delivery, type of anesthesia, Apgar
score, weight, height, head
circumference, reanimation, health
problems at birth, current sleep
- No significant correlation between
maternal or paternal nicotine
dependence and cigarette smoking,
and the postural, visual-motor,
language, social and overall child
development
- Negative correlation between
paternal nicotine dependence,
smoking and morning smoking and
the child’s language development
quotient
- Univariate analysis showed that
children of mothers without nicotine
dependence had higher mean visual-
motor development and language
quotients than child of dependent
mothers. There was no difference
59
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
pattern, type of feeding
- Fagerstrom Test for Nicotine
Dependence
between children of mothers or
fathers with or without dependence
on overall child development.
Scher et al.,
200899
Prospective
cohort study
A convenience sample
of 142 infants were
assessed. Infants were
participating in the
Training and Outcomes
for Early Identification
of Infants with
Neuromotor Delays.
Infants were born at
term (>37 weeks’
gestation), weighed
>2500 grams, and had
no postnatal infant
health problems or
congenital anomalies.
- Harris Infant
Neuromotor Test
(HINT) at 4-6 and 10
12 months of age
- Assessed general
motor development
***NOTE: lower
score indicates better
development***
- Alberta Infant
Motor Scale 4-6 and
10 12 months of age
- Assessed general
motor development
- Ages and Stages
Questionnaire at 4-6
and 10 12 months of
age
- Assessed fine
and gross motor
development
- Infant Sleep Questionnaire
- HINT scores were not associated
with scores from the Infant Sleep
Questionnaire
- Parental perception of child’s sleep
difficulty was associated with child
neurodevelopment at 10-12 months
of age, but not at 4-6 months of age
- Severity of sleep difficulties
significantly decreased with age in
the “no-risk group” and the “low risk
group”, but not in the “high risk
group”
- In the low-risk group, sleep
difficulties decreased with age,
whereas in the high-risk group, sleep
disruption increased over time
Schuler et
al., 2003100
Randomized
cohort study
A sample of 108 low-
income, inner-city,
drug-exposed children
were recruited.
- Bayley Scales of
Infant Development
at 6, 12 and 18
months of age
- Assessed general
motor development
- Home visit: visit date, time in the
home, who had custody of the
study child, if the mother or child
were in any programs, date of
child’s next physician visit,
whether the family was moving
soon
- Home intervention: based on the
“Infant Health and Development
Program”
- Maternal component: enhance
- No correlations were found between
ongoing alcohol or marijuana use and
mental or psychomotor development
- Mental development was higher
among infants in the intervention
group compared to the control group
- Motor development was higher
among infants in the intervention
group compared to the control group
60
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
mothers’ ability to manage self-
identified problems using existing
services and family and social
support
- Child component: to promote
infant development using a
program of games and activities
- Drug exposure: use of cigarettes,
alcohol, heroin, cocaine,
marijuana, amphetamines,
barbiturates, tranquilizers,
hallucinogens during pregnancy
Serenius et
al., 2013101
Prospective
cohort study
A sample of 491
extremely preterm
infants and 701 control
infants were enrolled.
- Bayley Scales of
Infant Development,
3rd edition at 2.5 years
of age
- Assessed general
motor development
- Parental education
- Child health and development
- Maternal age, parity and smoking
status
- Among preterm infants, language
and motor
developmental scores increase with
increased gestation age
- Language scores were lower among
preterm boys, but no sex differences
were observed for cognitive or motor
development
- No differences on developmental
scores were observe between
singleton vs. multiple birth or history
of congenital malformations
- Moderate or severe disabilities
decreased with advancing gestational
age and were more prevalent in boys
Sherlock et
al., 2008102
Retrospective
cohort study
A subset of 6664
families with children
of 2 years of age from
the Canadian National
Longitudinal Survey on
Children and Youth-
Cycle 3 were assessed.
- Motor and Social
Development Scale at
2 years of age
- Assessed general
motor development
- Demographic, parent and family
environment characteristics
- Covariates: duration of maternity
leave, sex, SES (education,
prestige of occupation, household
income) breastfeeding, number of
children in the household, preterm
birth
- Maternity leave duration as a
continuous variable in months was
associated with increased risk of
impaired performance on the Motor
Social Development scale (MSD)
- Boys scored lower on the MSD
- Higher SES and decreased number
of children in the household were
protective factors for development
- Preterm birth and breastfeeding
61
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
were not found to be associated with
the MSD
Singer et
al.,2012103
Prospective
cohort study
A sample of 96 mother-
child dyads were
enrolled into the study.
Dyads were not HIV
positive, no sign of
maternal
moderate/severe mental
retardation, no
psychiatric/medical
illness or child medical
illnesses.
- Alberta Infant
Motor Scale (AIMS)
at 4 months of age
> Assessed general
motor development
- Bayley Scales of
Infant Development,
1st edition at 4 months
of age
> Assessed general
motor development
- Behavioural Rating
Scale at 4 months of
age
> Assessed quality
of motor movements
- MDMA exposure via interview
- Prenatal levels of drug exposure:
adapted from the Maternal
Postpartum Interview
> measures tobacco, alcohol,
marijuana, MDMA, heroin,
ketamine, crack, cocaine,
benzodiazepine, LSD,
hallucinogenic mushrooms
- Drug Abuse Screening Test
- Brief Symptom Inventory
- Covariates: maternal age, marital
status, ethnicity, education,
household income, fetal growth
measurements
- Wechsler Abbreviated Scales of
Intelligence
- NICU Network
Neurobehavioural Scale (NNNS)
- Among those using MDMA during
pregnancy, the mean number of
tablets ingested per week was 3.2
- No significant differences by group
on the Bayley mental or the
attention/arousal factor of the
Behavioural Rating Scale between
MDMA exposed infants and
unexposed infants
- Difference existed between groups
on the Behavioral Rating Scale Motor
Quality Scale, with MDMA-exposed
infants demonstrating significantly
poorer motor quality
- MDMA infants were rated as less
coordinated and more likely to have
slower and delayed movements
- There was a dose-response effect,
with higher average MDMA use over
pregnancy predicting poorer motor
quality
- At 4 months, AIMS scores were
lower among infants exposed to
MDMA compared to the unexposed
controls
- Higher alcohol exposure also
predicted poorer motor quality at 4
months
- Higher marijuana exposure
predicted poorer attention and poorer
regulation on the NNNS at one month
Singer et
al., 2012104
Prospective
cohort study
A sample of 96 mother-
child dyads were
- Bayley Scales of
Infant Development,
- MDMA exposure via interview
- Prenatal levels of drug exposure:
- Higher amounts of MDMA
exposure predicted poorer mental and
62
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
enrolled into the study.
Dyads were not HIV
positive, no sign of
maternal
moderate/severe mental
retardation, no
psychiatric/medical
illness or child medical
illnesses.
1st edition at 12
months of age
- Assessed general
motor development
- Behavioural Rating
Scale at 4 months of
age
> Assessed quality
of motor movements
adapted from the Maternal
Postpartum Interview
> measures tobacco, alcohol,
marijuana, MDMA, heroin,
ketamine, crack, cocaine,
benzodiazepine, LSD,
hallucinogenic mushrooms
- Drug Abuse Screening Test
- Brief Symptom Inventory
- Covariates: maternal age, marital
status, ethnicity, education,
household income, fetal growth
measurements
- Wechsler Abbreviated Scales of
Intelligence
- Child Domain Scale of Parenting
Stress Index
- Home Observation of the
Environment
- Preschool Language Scale
motor outcomes and assessors’
ratings of poorer motor quality at 12
months of age
- MDMA exposure was unrelated to
language and emotional-regulation
outcomes
- Lighter MDMA-exposed infants
were equivalent to unexposed infants
on all outcomes
- The Home Observation of the
Environment was related to higher
mental development scores and better
emotional regulation, orientation, and
language scores
- Boys had lower mental
development and emotional
regulation scores
- Higher alcohol exposure predicted
better orientation and expressive
language
- Higher crack-cocaine exposure
predicted lower expressive language
scores
Singer et
al., 2016105
Prospective
cohort study
A sample of 96 mother-
child dyads were
enrolled into the study.
Dyads were not HIV
positive, no sign of
maternal
moderate/severe mental
retardation, no
psychiatric/medical
illness or child medical
illnesses.
- Bayley Scales of
Infant Development,
3rd edition at 24
months of age
> Assessed general
motor development
- Behavioural Rating
Scale at 4 months of
age
> Assessed quality
of motor movements
- MDMA exposure via interview
- Prenatal levels of drug exposure:
adapted from the Maternal
Postpartum Interview
> measures tobacco, alcohol,
marijuana, MDMA, heroin,
ketamine, crack, cocaine,
benzodiazepine, LSD,
hallucinogenic mushrooms
- Drug Abuse Screening Test
- Brief Symptom Inventory
- Covariates: maternal age, marital
status, ethnicity, education,
household income, fetal growth
- There is a significant effect of the
level of MDMA exposure on
psychomotor development over time
when adjusting for sex, test age,
parity, amount of prenatal cocaine
exposure
- There was no significant effect on
mental development scores and
MDMA exposure after adjusting for
child test age, HOME score at 12
months, sex
- There was a significant effect of
MDMA exposure on Behavioural
Rating Scale motor quality, with
63
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
measurements
- Wechsler Abbreviated Scales of
Intelligence
- Child Domain Scale of Parenting
Stress Index
- Home Observation of the
Environment
- Preschool Language Scale
heavier MDMA exposed children
being associated with poorer motor
quality than lighter or non-exposed
children
- Heavier MDMA-exposed infants
were perceived as having poorer
attentional skills than lighter exposed
infants
- Boys performed better than girls at
baseline on mental and motor scores,
however, there were significant
gender by age interactions that
resulted in boys performing worse
than girls as they got older
- Higher quality of the home
environment was also a predictor of a
higher mental development score and
better emotional regulation and motor
quality over time as rated by
examiners
Singer et
al., 1997106
Prospective
cohort study
Three groups of infants
(122 with
bronchopulmonary
dysplasia, 84 very-low-
birth weight without
bronchopulmonary
dysplasia, and 123 full-
term) were followed
longitudinally.
- Bayley Scales of
Infant Development,
1st edition at 8, 12, 24
and 36 months of age
- Assessed general
motor development
- Hospital chart review: gestational
age, birth weight, length, head
circumference, Apgar scores,
presence/absence of respiratory
distress syndrome,
bronchopulmonary distress
syndrome, patent ductus
arteriosus, necrotizing
enterocolitis, retinopathy of
prematurity, abnormal hearing test
results, number of days on
ventilator support, number of days
on supplemental oxygen, peak
bilirubin levels, septicemia,
neurologic risk score
- Cranial ultrasounds
- Infants with bronchopulmonary
dysplasia (BPD) achieved standard
scores significantly lower than very-
low-birth weight and term infants
- After controlling for social and
medical risk variables, BPD had
significant independent effects,
predicting poorer motor outcome
- Poorer mental developmental
outcome at 3 years was predicted by
minority race, lower social class,
lower birth weight and neurologic
risk score
- BPD independently accountant for a
12-point decrease in motor scores at 3
years, whereas neurologic risk
yielded an additional 14-point
64
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
decrement
- Neurologic risk accounted for a 10-
point decrement on mental
development scores
- Cognitive outcomes were
significantly associate with social
class within all risk groups
- there was no impact of social class
on motor development
Singer et
al., 1994107
Prospective
cohort study
A sample of 41cocaine-
exposed and 41 non-
exposed infants were
recruited.
- Bayley Scales of
Infant Development,
1st edition at 16-18
months of age
- Assessed general
motor development
- Hospital chart review: gestational
age, birth weight, length, head
circumference, Apgar scores,
presence/absence of respiratory
distress syndrome,
bronchopulmonary distress
syndrome, patent ductus
arteriosus, necrotizing
enterocolitis, retinopathy of
prematurity, abnormal hearing test
results, number of days on
ventilator support, number of days
on supplemental oxygen, peak
bilirubin levels, septicemia,
neurologic risk score
- Cranial ultrasounds: assessed for
intraventricular hemorrhage
- Cocaine-exposed infants has a
significantly increased incidence of
intraventricular hemorrhage than
non-exposed infants
- Cocaine-exposed infants performed
more poorly in cognitive and motor
skills when means scores were
compared
- When the incidence of
developmental delay was compared,
there was a significantly higher
incidence of disability in both mental
and motor domains in the cocaine-
exposed group
-Neither mental nor motor scores
were significantly different for
children placed outside the home
versus those who remained in the
care of their biological mothers
Slining et
al., 2010108
Prospective
cohort study
A subset of 217 mother-
infant dyads from the
Infant Care, Feeding
and Risk of Obesity
Study.
- Bayley Scales of
Infant Development,
2nd edition at 3, 6, 9,
12 and 18 months of
age
- Assessed general
motor development
- Infant anthropometric
measurements: weight, skin-fold
thicknesses (subscapular, triceps
and abdominal)
- Maternal height and weight
- Potential confounders: child sex,
age, maternal age, weight status
and education
- Male infants had significantly
higher weight-for-length z-scores
than female infants at 6 months only
- No significant sex differences in
motor development at any point
- Overweight infants were
approximately twice as likely as non-
overweight infants to have low
psychomotor scores
65
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
- Infants with high-subcutaneous fat
were more than twice as likely as
infants without high subcutaneous fat
to have a low psychomotor score
Smith et
al., 2000109
Prospective
cohort study
A sample of 114 infants
vertically infected with
HIV-1 were enrolled
- Bayley Scales of
Infant Development,
1st edition at 4, 9, 12,
15, 18, 24 and 30
months of age
- Infants had peripheral blood
specimens collected at <2 days of
life, < 7 days of life, and 1, 2 4, 6,
9, 12, 15 and 18 months of age and
every 6 months thereafter
- Interview: maternal education,
primary language, maternal drug
use, medical history, medical
regimens, presence of illness
- Prenatal use of illicit drugs
(opiates, cocaine, other injectables
and/or methadone): assessed via
urine toxicology and/or self-report
- Significant differences in
developmental scores between early
and late HIV infected were reported
- At 24 months, both motor and
mental scores among those early
infected were significantly lower than
those with late infections
- Both motor and mental scores
declined with age more rapidly in
early infected infants compared to
late infected infants
Stanton et
al., 1991110
Prospective
cohort study
A sample of 476 girls
and 510 boys were
enrolled at birth.
- McCarthy Motor
Scale at 5 years of
age
- Assessed general
motor development
- Perinatal complications index:
sum of the number of perinatal
complications experienced
- Health Index: sum of the number
of adverse health
exposure/conditions experienced
- Family Adversity Index: sum of
sociodemographic and family risks
- Child-rearing Index: measure of
child-rearing attitudes and
practices, and preschool
experiences
- Stanford-Binet Intelligence Scale
- Reynell Receptive and
Expressive Language Scales
- Adverse child-rearing practices
were associated with a relatively
higher level of perinatal complication
and a higher level of family adversity
- For boys, there was also a
significant association between an
adverse family background and a
poor level of health
- Effects of four indices of adversity
GIRLS:
IQ: Family background, child
rearing practices and child health
were predictive of IQ
Receptive Language: Predictors
were family background and child
rearing
Expressive Language: Predictors
were Family background and child
rearing
Motor Ability: Predictors were
66
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Family background, child rearing and
child health
- Effects of four indices of adversity
BOYS:
IQ: Predictors were perinatal
complications, family background,
child rearing and child health
Receptive language: Predictors
were perinatal complications, family
background and child rearing
Expressive language: Predictors
were family background
Motor ability: Predictors were
family background, child rearing and
child health
Swanson et
al., 1999111
Prospective
cohort study
A sample of 120
cocaine-exposed and
186 non-exposed infants
were enrolled.
- Movement
Assessment of Infants
(MAI) at 4 months of
age
> Assessed tone,
primitive reflexes,
automatic reactions,
volitional movements
- Maternal history of drug use:
Cocaine, crack, alcohol, tobacco
and marijuana before and during
pregnancy (self-report and hair
sample analysis – only for
cocaine)
- Significant difference were
observed in adjusted and unadjusted
models for Movement Assessment of
Infants total risk score between
cocaine-exposed and unexposed
infants
- Significant difference were
observed in only unadjusted models
for Movement Assessment of Infants
Primitive Reflexes and Volitional
Movement score between cocaine-
exposed and unexposed infants
- Significant difference were
observed in adjusted and unadjusted
models for Movement Assessment of
Infants total risk score and Volitional
Movement scores between cocaine-
exposure throughout pregnancy,
cocaine-exposure in first or second
trimester and unexposed
Significant differences were observed
in only unadjusted models for
67
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Movement Assessment of Infants
Primitive Reflex scores between
cocaine-exposure throughout
pregnancy, cocaine-exposure in first
or second trimester and unexposed
Tauman et
al., 2015112
Prospective
cohort study
A sample of 74 women-
infant dyads were
recruited. Women were
in the third trimester of
a singleton,
uncomplicated
pregnancy.
- Spontaneous general
movement assessment
at 48 hours of life, 8-
11 weeks, 14-16
weeks of age
>Assessed
spontaneous general
movements
- Infant
Developmental
Inventory
questionnaire at 1
year of age
> Assessed general
motor development
- Sleep questionnaire during
second trimester
- Sleep study during third trimester
- Brief Infant Sleep Questionnaire
at 1 year of age
- Hollingshead 2-factor index of
socioeconomic status
- No significant differences were
found between the maternal sleep-
disordered breathing and control
groups before and after adjustments
- No significant difference was found
in the gross and fine motor, language,
and self-help development scores
between the maternal sleep-
disordered breathing and control
groups
- No significant differences in
nocturnal sleep duration, daytime
sleep, number of nocturnal
awakenings, sleep latency, and wake
after sleep onset and frequency of
problematic sleep were found
between the maternal sleep-
disordered breathing and control
groups
68
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Trasti et al.,
1999113
Prospective
cohort study
A sample of 376
mother-infant dyads
were recruited.
- Bayley Scales of
Infant Development,
1st edition at 13
months of age
> Assessed general
motor development
- Peabody
Developmental Motor
Scales
> Assessed general
motor development
- Maternal smoking status and
education
- Home Screening Questionnaire
(HSQ)
- Wechsler Preschool and Primary
Scales of Intelligence
- At 13 months, children of smokers
and non-smokers performed equally
well on the mental and psychomotor
components of the Bayley Scales of
Infant Development
- IQ scores were significantly lower
among children of smokers compared
to children of non-smokers
- Significant differences were
observed in fine motor coordination
and balance between smokers and
non-smokers in adjusted models
- A dose-response relationship was
observed between the number of
cigarettes smoker per day during
pregnancy and the child’s balance
(increased number of cigarettes were
related to lower child scores)
Valtonen et
al., 2004114
Cross-
sectional
study
A sample of 434
children were selected
from the same age
cohort of children
registered at 16 children
health centers in
Finland.
- Lene test at 4 years
of age
- Assessed Motor-
Perceptual
development
- Child variables: sex, urban vs
rural residency
- Parent variables: education
- Isolated delays were general mild
- Co-occurring delays were more
frequently moderate or severe
Van der
Sluijs Veer
et al.,
2012115
Prospective
cohort study
A sample of 95 toddlers
with neonatal congenital
hypothyroidism were
recruited.
- Bayley Scales of
Infant Development,
2nd edition at 1 and 2
years of age
- Assessed general
motor development
- Heel puncture results, gestational
age, birth weight, treatment
strategy
- Mental development scores among
children with severe, moderate and
mild congenital hypothyroidism were
similar to the population at 1 year of
age, but the severe group was
significantly lower than the
population at 2 years of age
- Psychomotor development scores
among children with severe,
moderate and mild congenital
hypothyroidism were significantly
lower than the population at both 1
69
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
and 2 years of age
- Initial thyroxine concentrations and
starting dose of thyroxine were
significant predictors of mental
development at 1 year and
psychomotor development at 1 and 2
years
Vilahur et
al., 2014116
Prospective
cohort study
A sample of 423
infants-mother dyads
were recruited.
Pregnancies were
singletons without
assisted conception.
- Bayley Scales of
Infant Development,
1st edition at 14
months of age
- Assessed general
motor development
- Total effective xenoestogen
burden
- Sex, social class, and site of
recruitment
- Potential confounders:
gestational age, type of delivery,
previous abortions, gestational
diabetes, marital status, maternal
age, height, BMI, gestational
weight gain, parity, smoking,
alcohol consumption,
breastfeeding practices, season of
birth, urbanicity, country of birth,
maternal education, paternal
height and weight, Apgar score
- No psychomotor differences
observed between sexes
- No significant differences between
xenoestrogen levels and mental or
psychomotor development
Wehby et
al., 2008117
Cross-
sectional
survey
A subset of 6774
mother-child dyads
were assessed from the
National Maternal
Infant Health Survey.
- Adapted from
Denver
Developmental
Screening Tools at 3
years of age
- Assessed general
motor development
- Prenatal use of vitamins and
minerals
- Covariates: prenatal care,
smoking, alcohol and recreational
drug use, maternal health, age
education, child age, sex, race,
number of children in household,
household income
- Folic acid supplementation was
associated with reduced odds for
moderate risk on the motor
development
- Calcium use was associated with
increased odds for high risk on
overall development and motor
development, and for moderate risk
on personal-social development
Wouldes et
al., 2014118
Prospective
cohort study
A subset of 103
methamphetamine
exposed infants and 107
non-exposed infants
were assessed from the
New Zealand Infant
- Bayley Scales of
Infant Development,
2nd edition at 1,2 and
3 years of age
> Assessed general
motor development
- Substance use inventory:
quantity and frequency of prenatal
drug use
- Current household structure,
SES, quality of home environment
- Peabody Picture Vocabulary
- No effects of methamphetamine
exposure on gross or fine motor
development at 1 year of age
- At 3 years of age, gross motor
development was significantly lower
among infants exposed to prenatal
70
Author
(Year)
Study
Design Study population
Neurodevelopment
Test Factors investigated
Results related to motor
development
Development,
Environment and
Lifestyle study.
- Peabody
Developmental Motor
Scale, 2nd edition at 1
and 3 years of age
>Assessed fine
and gross motor
development
Test, 3rd edition
- Covariates: gender, birth weight,
ethnicity, drug use, SES
methamphetamine compared to non-
exposed infants
- At 1 and 2 years of age,
methamphetamine exposed was
associated with lower psychomotor
scores compared to non-exposed
infants
-
Zwicker et
al., 2013119
Retrospective
cohort study
A sample of 157 very-
low-birth-weight
children were enrolled.
- Movement
Assessment Battery
for Children at 4-5
years of age.
- Assessed general
motor development
- Perinatal variables: antenatal
steroid use, premature rupture of
membranes greater than 18h,
mode of delivery, plurality, Apgar
scores, gestational age, birth
weight
- Neonatal variables: days of
supplemental oxygen, days of
ventilation, postnatal steroids,
patent ductus arteriosus,
necrotizing enterocolitis,
retinopathy of prematurity, sepsis,
hyponatremia, cranial ultrasound
abnormalities
- Males, low-birth weight and
postnatal exposure to steroids were
independently associated with low
motor development scores
- Significantly more boys scored in
the range of developmental
coordination disorder than girls
71
2.2.1.1 Sociodemographic factors
The effect of socio-demographic characteristics on child motor development are
commonly assessed or controlled for in the literature61,62,75,81,82,85,90,92,102,106,118. The results
regarding the association between sociodemographic factors and motor development, however,
have been conflicting as evidenced by studies investigating the association of socioeconomic
status (SES) or parental age on motor development. For example, in their 3-year longitudinal
follow-up of 329 infants, Singer et al. did not find an association with socioeconomic status
(SES), classified using the Hollingshead Four-Factor Index of SES, and low motor scores (p-
value=0.89)106. In their prospective cohort study of 117 infants Mazer et al, however, found that
infants of families with moderated Hollingshead Index scores exhibited poorer psychomotor
development scores on the Bayley Scales of Infant Development compared with infants of
families with high Index scores81.
In the literature, the use of the Hollingshead Four-Factor Index of SES is uncommon;
rather studies typically employ proxy measures of SES including maternal education and
intelligence, employment status, household income and/or marital status58,61,69,70,74,79,90,97.
Associations between proxy measures of SES and motor development are well supported. For
example, while examining the interaction between maternal intelligence and child
neurodevelopment, Ronfani et al. evaluated the intelligence of 900 mothers using the Standard
Progressive Matrices, a test of nonverbal reasoning ability and general intelligence96. Through
their analysis, Ronfani et al. described that when comparing the highest quintiles of maternal
intelligence to the lowest, increased maternal intelligence was associated with higher infant
motor development scores on the Bayley Scales of Infant and Toddler Development-III at 18
months of age.
72
Similar associations have also been described between years of maternal education and
child motor development. In a prospective cohort study of 6850 infants from the Early
Childhood Longitudinal Study – Birth Cohort, Hinkle et al. suggested that increased maternal
education was associated with higher psychomotor development scores on the Bayley Scales of
Infant Development-II70. In addition to reporting lower motor scores among infants of mothers
with low maternal education, Hinkle et al. also reported lower scores among infants of
single/unmarried mothers, an association also well supported by the literature74,80,147. The
prospective nature, large sample size and rigorous methodology of both these studies provide
strong evidence for an association between proxy measure of maternal SES and infant motor
development70,96.
Parental age has also been shown to be associated with motor
development69,74,80,144,145,147. In their assessment of 915 toddlers involved in the Avon
Longitudinal Study of Parents and Children, Little et al., described that poorer locomotor scores
18 months of age were associated with increased maternal age80. Furthermore, Majnemer et al.
described in both their cross-sectional145 and cohort analysis144, that both increased maternal and
paternal age were associated with decreased motor scores on the Alberta Infant Motor Scales.
The literature reporting on the influence of ethnicity and a child’s sex on general motor
development is supported by evidence from methodologically robust studies. In the analysis of
4901 children from the longitudinal Upstate KIDS cohort of New York, Wylie et al. described
that children of non-Hispanic white mothers took longer to crawl and to stand alone compared
with other ethnicities161. Moreover, children of Latina mothers have been shown to score lower
on the Bayley Scales of Infant Development Psychomotor Development Index (p-value<0.05)65.
Lower motor and social development among Mexican-Americans was also reported by Hediger
73
et al. in their analysis of the third National Health and Nutrition Examination Survey conducted
in the USA69.
Finally, among studies that found associations between motor development and the
child’s sex, males have frequently shown to exhibit poor motor development compared with
females69,70,73,90,154. For example, in their analysis of 348 children aged 13 months, Janssen
demonstrated that males scored significantly lower on the psychomotor subscales of the Bayley
Scales of Infant Development, second edition, compared to females73. Using the same
assessment of neurodevelopment, Hinkle et al. reported similar results in their aforementioned
analysis70; among 6850 children 20-38 months of age, males exhibited significantly lower
psychomotor motor scores than females.
In sum, an association between SES, ethnicity65,69,161 and a child’s sex69,70,73,90,154, and
general motor development is clearly supported in the literature. Although the results for the
independent associations between factors such as living and housing arrangements51,58,96, urban
or rural residency63,114 and whether the family receives support from the government72,77 and
motor development are not presented in the literature, models are commonly adjusted for these
factors.
2.2.1.2 Maternal health factors
The research investigating the influence of maternal health on general motor
development has included studies considering aspects of both maternal physical and mental
health. For example, in Wylie et al.’s analysis of the longitudinal Upstate KIDS study, they
described the long-term effects of pre-pregnancy obesity on early child development161. In their
study, infants born to obese, but not overweight, mothers exhibited delays in early motor
74
milestone attainment (i.e. sitting without support and crawling) compared with infants of thin or
normal-weight mothers. Given the association between maternal obesity and motor development,
studies commonly control for maternal BMI before70,96 and during116 pregnancy, gestational
weight gain116 and weight postpartum108.
Along with their investigation of the influence of pre-pregnancy maternal BMI on motor
development, Polanska et al., also studied maternal leisure-time physical activity and folic acid
supplementation on the motor outcomes of 538 children involved in the Polish Mother and Child
Cohort Study92. Their analysis revealed a significant association between poor motor
development at both 1 and 2 years of age with both decreased leisure-time physical activity and
failure to supplement with folic acid. Though the analysis of maternal leisure-time physical
activity is unique in the literature, other studies have revealed similar associations between folic
acid supplementation and motor development. In a 2009 prospective, longitudinal analysis of
482 mother-baby dyads, Julvez et al. described a significant increase in motor scores at 4 years
of age (p-value<0.01) among children born to mothers taking folic acid supplements75. As
Spain’s 2008 state-level survey data suggests that only 0.13-12.8% of the population were folate
deficient120, the folic acid supplementation in this study may have represented doses higher than
recommended. Moreover, based on the state level survey data120, mothers not taking folic acid
supplements were likely not folate deficient. As such, these results support the importance of
folic acid supplementation during pregnancy for motor development75,92.
The relationship between maternal seafood consumption and child neurodevelopment has
also been investigated. In a prospective cohort study in 2008, Mendez et al. reported that infants
of mothers consuming fish greater than 2-3 time per week exhibited significantly higher scores
on all subscales of the McCarthy Scales of Children’s Abilities test84. No significant differences,
75
however, were observed among mothers eating other forms of seafood excluding fish (i.e.
shellfish) or child consumption of seafood.
In additional to maternal physical health, the literature has also explored the effects of
maternal mental health on general motor development. The importance of factors influencing
maternal mental health on child neurodevelopment is reflected by the numerous studies
investigating the effect of perceived stress, depression, anxiety, social support or parental
interactions on motor development51,57,58,60,68,71,74,77,93,95,103-105,147,150. For example, Huizink et al.
examined the effects of maternal anxiety and stress during pregnancy on developmental
outcomes of 170 singleton infants at 3 and 8 months of age71. In this prospective cohort study,
maternal anxiety measured as a strong fear of giving birth by mothers during mid-pregnancy (27-
28 weeks’ gestation) was related to poor psychomotor development scores by infants 8 months
of age on the Bayley Scales of Infant Development (p-value<0.01). Moreover, high salivary
cortisol levels during late pregnancy (37-38 weeks’ gestation) were also related to poor
psychomotor development scores at both 3 and 8 months of development (3-months: p-
value<0.01; 8 months: p-value<0.05).
Recently, the effects of alcohol59-61,63,71,72,75,77,79,82,85,90,92,93,95,96,100,103-105,111,154,
cigarettes52,61,75,79,82,85,90,95,103-105,154, cocaine72,77,82,85,90,95,100,103-105,154, marijuana72,77,82,85,90,95,100,103-
105,154, opiates72,77,82,109 and other illicit77,100,103-105 drugs during pregnancy on motor development
have been explored. Amongst others, Polanska et al. and Singer et al. described a significant
association between cigarettes92 or cocaine106 use during pregnancy and motor development
delays. Moreover, the results from Richardson et al.’s analysis of 320 mother-baby dyads
participating in a one-year follow-up study suggest that maternal self-report of alcohol
consumption during any trimester, or cocaine use during the second trimester may significantly
76
affect general motor development95. Finally, fetal exposure to opiates during pregnancy,
validated using meconium screening, was associated with children exhibiting significantly lower
psychomotor development scores on the Bayley Scales of Infant Development, compared to
children with no opiate exposure82. Together, these cohort studies provide strong evidence for an
association between prenatal drug and alcohol use, and delayed motor development given their
prospective nature and large sample sizes.
Maternal physical and mental health, and lifestyle have been shown to influence motor
development. The affect of maternal BMI and folic acid supplementation on child motor
development is well reported in the literature75,92,116,161. Moreover, many cohort studies have
described associations between maternal consumption of alcohol, tobacco or illicit drugs during
pregnancy and poor motor development59-61,63,71,72,75,77,79,82,85,90,92,93,95,96,100,103-105,111,154. Given the
scarcity of studies directly investigating maternal optimism and parenting morale, further
prospective research is required to understand the influence of these factors on motor
development.
2.2.1.3 Pregnancy and birth outcome factors
Given the increased survival rate of babies born prematurely, many studies have
investigated the long-term influence of gestational age and birth weight on motor developmental
outcomes51,52,56,61-63,65,67,70,71,73-75,78,82,86,89,92,96,106,107. In their recent longitudinal study
investigating 371 children born <32 weeks’ gestation and admitted to the neonatal intensive care
unit (NICU), Janssen et al., described that nearly 40% of the children born preterm exhibited
motor developmental delays73. Moreover, Wiley et al. described that preterm birth, low birth
weight (i.e. <2500g) and small-for-gestational-age were all risk factors for poor motor milestone
77
attainment161. Similar studies have also shown that decreased head circumference and small-for-
gestational-age infants are at increased risk for overall motor delay78,90,148. Though children
considered small-for-gestational-age typically undergo catch-up growth, evidence suggests that
their delays in motor development persist past 2 years of age.
Due to intrauterine growth restrictions, multiple birth pregnancies are typically excluded
from many studies in the literature. Datar et al., however, included twins in their longitudinal
analysis investigating the effect of birth weight on child development at 9 months and 2 years of
age in America63. Using 6,750 singleton births, 625 twin pairs (525 fraternal, 100 identical) and
50 twins and other higher-order births, their study failed to find an association between low-birth
weight and poor motor development. As twins were included in the study, both genetic and
environmental factors were controlled. Therefore, even though low-birth weight was
significantly associated with poor motor development based on cross-sectional data, within-twin
comparisons for both fraternal and identical twins did not find an association between birth
weight and motor development. This study contradicts the previous evidence provided in the
literature69,106,145,154 and reveals that when maternal, environmental and genetic factors are
controlled for, birth weight is not significantly associated with motor development at 9 or 24
months of age.
Beyond studies investigating gestational age, birth weight and delivery type51,52,56,61-
63,65,67,70,71,73-75,78,82,86,89,92,96,106,107, few studies have investigated the effect of other pregnancy or
birth outcomes. Though it is common for studies to adjust models according to NICU admission
and Apgar scores52,60,97.98,103-107,119, the independent associations between these variables and
motor development are not described. As such, description for the association between
pregnancy and birth outcome factors, such as intrauterine growth restrictions, Apgar scores,
78
NICU admission, antenatal steroid use and pregnancy complications, and motor development are
required.
2.2.1.4 Child health factors
Though there are a myriad of child health complications that may influence motor
development, studies have generally targeted cardiovascular disorders, neurological disorders
and neonatal conditions73,78,89,91,107. For example, in their analysis of bronchopulmonary
dysplasia and motor development, Singer et al. also investigated the effects of patent ductus
arteriosus, neurologic risk scores, intraventricular hemorrhage, septicemia and retinopathy of
prematurity on motor development107. Among their cohort of 329 infants 16-18 months of age
they found that bronchopulmonary dysplasia and neurologic risk score were significantly
associated with poorer motor outcomes on the Bayley Scales of Infant Development.
Intraventricular hemorrhage, patent ductus arteriosus, septicemia and retinopathy of prematurity
were not associated with motor development. A case-control study by Ohman et al. also
suggested that congenital muscular torticollis was associated with poor motor development at 2
and 6 months of development91.
Evidence for the long-term effect of children’s’ physical health on motor development
has also been described. In an analysis of 217 infants enrolled in the Infant Care, Feeding, and
Risk of Obesity Project, a longitudinal study of low-income African American mother-infant
dyads, Slining et al. investigated infant weight and its influence on motor development108.
Within this cohort, overweight infants had 1.67 (95% CI: 1.01-2.79) times the odds of exhibiting
motor development delays of normal-weight infants. Moreover, infants with high subcutaneous
fat had 2.21 (95% CI:1.18-4.14) times the odds of motor delay when compared with infants with
low subcutaneous fat. These results, however, differ from a similar analysis of 37 preterm infants
79
in a longitudinal study in Japan76. In their study, Kanazawa et al. described a correlation between
increased subcutaneous fat gain and increased motor ability41. Using ultrasound imaging,
Kanawaza et al. also noted that motor development was not significantly correlated with muscle
size. These conflicting results may be due to the small sample size in Kanazawa et al.’s study
and therefore their inability to control for potential confounders. Moreover, as 29% of infants 18
months of age assessed by Slining et al. scored >90th percentile in weight-for-length z-scores108,
their sample may have been significantly more obese than the sample of infants 18 months of age
assessed by Kanazawa et al76l. As such, increased subcutaneous fat may be associated with
increased motor achievement among normal weight infants, however, excess subcutaneous fat
may be a risk factor for delayed motor development.
The co-occurrence of chronic developmental disorders and motor development has also
been reported. In a longitudinal analysis of 434 Finnish children, Valtonen et al. found that
delayed motor development was associated with co-occurring developmental delays, such as
attention-behavioural and language delays114. In addition to the increased risk of motor
developmental delays, the severity of the delay was higher when they co-occurred with other
delays.
In sum, the literature supports the association between a child’s history of medical
conditions, excess weight and co-occurrence of developmental disorders, and delayed motor
development.
2.2.1.5 Environmental factors
A child’s environment has been shown to be highly influential on their motor
development72,77,79,82,88,93,95,100,103-105,113. It has been hypothesized that children of low-income
80
families may have less stimulating environments, such as less space inside the home to safely
explore, fewer age appropriate toys and less parent-child interaction time, increasing the risk of
developmental delay177,178. Evidence supporting this hypothesis is described by Piteo et al. by
evaluating the home environment using the Home Screening Questionnaire (HSQ)151. In their
case-control study, children with more stimulating home environments exhibited higher
cognitive, language and general motor development scores. Similar results were also described
by Messinger et al., in their analysis of a subset of 1227 American mother-children dyads from
the Maternal Lifestyle Study, a prospective cohort study82. In their analysis, higher HOME
scores, indicative of more stimulating home environments, were associated with higher
psychomotor scores on the Bayley Scales of Infant Development, second edition.
In addition to creating a stimulating home environment, parenting resources have also
been shown to influence motor development. For instance, Black et al.58, Wiley et al161., Hinkle
et al.70 and Nelson et al.90 described that increased parity was associated with poor motor
development23,26. Moreover, Polanska et al. suggested that the increased number of siblings in a
home is also associated with poor motor development92. These results align the hypothesis that
with each additional child, parental support becomes diluted144,185 resulting in less available
resources aimed at supporting the child in their developmental progression.
Finally, the effect of how a child interacts with their environment on their motor
development has also been examined. In 2006, Majnemar et al. examined the effect of sleeping
position on 121 children’s motor development144. This study revealed that children put to sleep
in the prone position had significantly better motor scores than those put to sleep in the supine
position. Moreover, children spending more awake time in the prone position also had
significantly better motor scores than those spending more time in the supine position. Studies
81
investigating sleeping position, however, face many limitations, including misclassification bias
resulting from a child’s ability to change their sleeping position as they age144,145. Moreover, due
to recommendations by organizations including the Canadian Pediatric Society that encourages a
supine sleeping position due to its association with lower rates of sudden infant death syndrome,
few children slept in the prone position144,145. Therefore, results from these studies lack a
sufficient number of infants sleeping in the prone position to compare the association between
sleep positions and motor development.
Currently, the best quality evidence suggests that the home environment influences motor
development. Given the popularity of computers and tablets, future research should investigate
the influence of various types of stimulations available to children in their home environment on
motor development55.
2.2.2 Risk Factors for Delayed Fine or Gross Motor Development
As screening tools continue to adapt to accommodate new insights into child
development, studies are increasingly able to differentiate between risk factors for either fine or
gross motor development128. The influence of socio-demographic, maternal health, pregnancy
and birth outcome, child health, and child environmental risk factors on either fine or gross
motor development are described here. A summary of the included articles assessing fine and
gross motor development are presented in Table 3.
82
Table 3. Summary of articles examining factors associated with fine and/or gross motor development in children 1-66 months
of age
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
Arendt et
al., 1999120
Prospective
cohort study
A sample of 260
infants and young
children were
recruited from a
newborn nursery
or at-risk pediatric
clinic.
- Peabody
Developmental Motor
Scales (PDMS) at 2
years of age.
- Assessed fine and
gross motor
development
- Mother’s demographics and
medical information
- Infant demographics and
medical information
- Maternal Postpartum Drug
Interview
- Tobacco, alcohol, marijuana
and cocaine use
potential confounders: infant
race, gender, 5-minute APGAR
score, gestational age, length,
weight, head circumference,
number of prenatal visits,
marital status, age at delivery,
education level, family income,
number of persons living in the
home.
- Cocaine exposed children did significantly
poorer than non-exposed children in the
following: Fine motor development (hand
use, eye-hand coordination, total score) and
gross motor development (balance, receipt
and propulsion)
- Significant correlations with gross motor
development: maternal age, alcohol month
before pregnancy or during first trimester,
cocaine use during first trimester,
gestational age, birth weight and length
- Significant correlations with fine motor
development: maternal age, cocaine use
during first trimester, gestational age, birth
weight and length, head circumference
- Confounding both fine and gross motor
development: maternal age, education and
number of prenatal visits
Regression for fine motor development:
Cocaine exposure was a significant
predictor of hand use and eye-hand
coordination.
Regression for gross motor development:
severity of alcohol use before pregnancy
predictor for receipt and propulsion subscale
Austin et al.,
2013121
Prospective
cohort study
A sample of 35
antidepressant-
exposed infants
and 23 non-
exposed infants
were recruited.
Mothers in the
exposed group
used
- Bayley Scales of
Infant Development,
3rd edition at 18
months of age
- Assessed both fine
and gross motor
development
- Demographic and clinical
information (age, marital status,
obstetrical history, education
level, cigarette, alcohol and
recreational drug use during
pregnancy, perinatal outcomes)
- Medication Calendar (name
and dosage and compliance of
antidepressant use)
- Antidepressant exposed infants did not
score significantly different on cognitive,
receptive language, expressive language,
fine motor or gross motor development than
non-exposed infants
83
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
antidepressant for
1 month during
pregnancy.
Mothers in
control group had
no history of
mood disorders
and not using
antidepressants or
psychotropic
medication. No
mothers currently
used alcohol or
illicit drugs,
diagnosed with
other mental
health disorders
or significant
obstetrical
history.
- Edinburgh Postnatal
Depression Scale
- National Adult Reading Test
- MINI-Plus interview for
mental health disorders
Bigsby et
al., 2011122
Prospective
cohort study
A sample of 370
cocaine-exposed
infants and 533
non-exposed
infants were
recruited into the
Maternal
Lifestyle Study.
Mothers were
older than 18
years of age,
mostly African
American with at
least a high
school education.
- Posture and Fine
Motor Assessment of
Infants
- Assessed postural
and fine motor
development
- Legal and illegal drug use
during pregnancy (cocaine,
alcohol, marijuana, tobacco)
- Groups were matched on
gestational age, race and gender
- Cocaine exposed infants scored lower than
control infants on postural scores when
controlling for testing site, gestational age,
SES and, prenatal exposure to alcohol,
tobacco and marijuana
- Infants <33 weeks’ gestation scored lower
on postural and fine scores than infants >33
weeks’ gestation
- No significant effect of SES or, cocaine,
alcohol or tobacco use on either postural or
fine motor scores
- Prenatal exposure to marijuana did
significantly affect fine motor scores
Case-Smith,
1993123
Prospective
cohort study
A sample of 65
full-term and 25
- Posture and Fine
Motor Assessment of
- Corrected gestational age
- Medical Risk
- Preterm infants scored lower on all aspects
of postural control and fine motor skills
84
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
preterm infants
were recruited.
Full-term infants
were born within
2 weeks of due
date, healthy
histories, no
unusual medical
procedures or
problems. Preterm
were born prior to
37 weeks’
gestation,
weighed 2000
grams or less and
had one or more
significant
medical problems
during the
neonatal period.
Infants
- Assessed postural
and fine motor
development
- Postural control was significantly greater
in full-term infant than high risk preterm
infants
- Fine motor skills were significantly greater
in full term infants than both high and low
risk preterm infants
Carmeli et
al., 2008124
Prospective
cohort study
A sample of 80
full-term infants
were recruited
into the study. All
infants were born
to unmedicated,
uneventful
pregnancies and
deliveries from
non-smoking,
non-alcoholic
two-parent
families.
- The Alberta Infant
Motor Scale (AIMS)
at 6 months of age
- Assessed gross
motor development.
- Sleep position log (position put
to sleep and position upon
awakening)
- Position while awake
- Preferred position
- Duration of play position
- No significant correlations between infant
positions and motor development were
found
Cruise &
O’Reilly,
2014125
Prospective
cohort study
A sample of
10748 nine-
month-old infants
were recruited in
- Ages and Stages
Questionnaire, 2nd
edition at 9 months of
age
- Socio-environmental
information: partner resident in
the household, number of
siblings in the house, infant
- Risk of poor gross motor development:
one or more sibling, gestational age 25-36
weeks, birth weight <2500 grams, mothers
age 35+ years
85
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
the Growing Up
in Ireland study.
- Assessed fine and
gross motor
development
receiving non-parental care from
a relative, non-relative, or a
center
- Confounding variables:
gestational age, birth weight,
gender, maternal ethnicity, age,
education, household income,
living in urban or rural setting
- Protective factors for gross motor
development: birth weight 3501-4000grams,
not Irish white
- Risk of poor fine motor development:
gestational age 25-36 weeks, male, mothers
age between 16-19 or 20-24, only secondary
education
De Kegel et
al., 2016126
Prospective
cohort study
A sample of 64
children
diagnosed with
congenital
cytomegalovirus
infections were
enrolled. In the
sample, 26 infants
were symptomatic
and 38 were
asymptomatic.
The infected
children were also
compared to 107
uninfected,
typically
developing
children.
- Peabody
Developmental Motor
Scales, 2nd edition,
Alberta Infant Motor
Scales and Ghent
Developmental
Balance Test at 6, 12
and 24 months of age,
in randomized order
- Assessed gross and
fine motor
development and
balance
- The symptomatic group performed worse
than the control group for all gross motor
outcomes at 6, 12 and 24 months and worse
than the asymptomatic group on PDMS
gross and the AIMS at 6 and 12 months, and
the GDBT as 24 months
- Asymptomatic group performed weaker
than control group in gross motor at 12 and
24 months
- Symptomatic and asymptomatic groups
gave greater risk of gross motor delays, but
for the asymptomatic group this may be
related to sensorineural hearing loss
Eek
Brandlistuen
et al.,
2013127
Prospective
cohort study
A subset of 48631
children from the
Norwegian
Mother and Child
Cohort Study
were used in this
study. Within the
sample there were
2919 same-sex
sibling pairs who
were used to
- Ages and Stages
Questionnaire at 36
months of age
(assessed fine and
gross motor
development)
- Age child began
walking unassisted
- Paracetamol and Ibuprofen
use: gestational age of exposure,
age of exposure postpartum,
number of days of use at each
time point
- Behaviour: externalizing and
internalizing behaviour
measured by the Child
Behaviour Checklist
- Temperament: Emotionality,
Activity and Shyness
- In the sibling-control analysis, long-term
paracetamol exposure (>28 days) associated
with poor gross motor functioning, delayed
age of walking, poor communication skills,
externalizing and internalizing behaviour
problems, and active temperament
- No interaction effect between trimester
and exposure on any outcome
- In the cohort analysis, long-term
paracetamol exposure associated with poor
gross motor functioning, poor
86
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
adjust for familial
and genetic
factors.
Temperament Questionnaire
- Potential Confounders:
maternal health before and
during pregnancy, fever, back
pain, head ache or migraine, use
of nonsteroidal anti-
inflammatory drugs, triptans,
opioids, other analgesics,
antipsychotics, antidepressants,
benzodiazepines, antiepileptic
drugs, maternal age, years
between pregnancies, parity,
smoking and alcohol use during
pregnancy, maternal education,
and maternal chronic diseases
- Hopkins Symptom Checklist
(psychological distress)
communication skills, externalizing
behaviour problems, and negative
emotionality
- In the sibling-analysis, short term
paracetamol exposure (<28 days) was
associated with poor gross motor
functioning
- In the cohort analysis, short term
paracetamol exposure was associated with
poor gross motor development,
externalizing behaviour and negative
emotionality
- No associations between ibuprofen and
any of the outcomes in adjusted models
Evlampidou
et al.,
2007128
Prospective
cohort study
A subset of 179
mother-baby
dyads from the
Rhea Study in
Crete, Greece.
- Bayley Scales of
Infant and Toddler
Development, 3rd
edition at 18 months
of age
- Assessed fine and
gross motor
development
- Detailed information on
sociodemographic information,
smoking, dietary, and lifestyle
patterns
- Smoking during pregnancy:
total cotinine levels in urine at
12th and 30th week of pregnancy
- Exposure to second-hand
smoke
- Poorer gross motor development scores
were associated with increased urinary
cotinine levels. No other domains exhibited
associations with urinary cotinine levels
- No associations between sex and gross
motor development in adjusted models
Galbally et
al., 2011129
Case-control
study
A sample of 22
antidepressant
exposed infants
was matched to
19 unexposed
infants. Eligibility
required that
women not have a
substance
dependence,
- Bayley Scales of
Infant Development,
third edition at mean
age of 23.09 months
(SD: 3.82) for the
control group and
28.53 months (SD:
6.22) for the exposed
group.
- Maternal Characteristics:
demographics, reproductive and
medical history, alcohol, tobacco
or illicit drug consumption,
prescription medication use,
maternal stress, marital status,
employment and mental health
services utilization
- Birth Outcomes: delivery
method, gestational age,
- No association found between
developmental outcomes and antidepressant
use (study under-powered)
- Significant association between higher
expressive language performance and
increased depression rating during
pregnancy
87
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
intellectual
disability, serious
physical illness or
psychiatric
illness. Women
were also
proficient in
English.
- Scores were scaled
to correct for age
differences
- Assessed fine and
gross motor
development
APGAR scores, birth outcome
and perinatal complications
- Antidepressant use: type,
dosage and duration of exposure
- Beck Depression Inventory, 2nd
edition
Ghassabian
et al.,
2015130
Prospective
cohort study
A subset of 4909
mother-child
dyads from the
Upstate KIDS
cohort study were
examined.
- Six gross motor
milestones: sitting
without support,
standing with
assistance, hands-
and-knees crawling,
walking with
assistance, standing
alone, walking alone
- Used WHO 90th
centile’s
- Pregnancy information:
gestational
diabetes/hypertension/eclampsia,
pre-eclampsia, HELLP
syndrome
- Medical history: chronic
diabetes mellitus, hypertension,
hypothyroidism,
hyperthyroidism, cardiovascular
disease, autoimmune disorders
- Maternal and child
information: maternal age,
education, race/ethnicity, history
of smoking, alcohol
consumption, gestational age,
birth size and sex
- Infants of mothers with gestational
diabetes took longer to walk with assistance
- No significant delays among infants of
mothers with gestational hypertension in
adjusted models
- No significant delays among infants of
mothers either pre-eclampsia, eclampsia or
HELLP syndrome in adjusted models
- Compared to unexposed infants, infants of
mothers with diabetes took longer to stand
with assistance, walk with assistance, and
walk alone
- No associations found with maternal
chronic hypertension, hypothyroidism,
hyperthyroidism before or during pregnancy
and gross motor development
- Maternal cardiovascular disease was
associated with a shorter time to walking
alone, whereas autoimmune disease was
associated with a longer time to achieve
crawling.
Gonzalez-
Valenzuela
et al.,
2015131
Retrospective
cohort study
A subset of 146
children were
randomly selected
from a newborn
registry of 7465
in Spain.
- Batelle
Developmental
Inventory at a mean
age of 56.32 months
(SD=3.42 months)
- Assessed both fine
- Exposure to synthetic oxytocin
during delivery
- Control variables: maternal
age, type of labor, duration of
labor, twin pregnancy, sex and
gestational age
- Significant association between gross and
fine motor development delays and
exposure to synthetic oxytocin
- Labor longer than 4 hours and being male
were also associated with gross motor
delays
- No significant associations between fine
88
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
and gross motor
development
motor development and control variables
- Exposure to synthetic oxytocin associated
with gross motor delays, and relationship
influence by the child’s sex
-
Goyen &
Lui, 2002132
Prospective
cohort study
A sample of 85
children were
recruited. Of the
85 children, 13
were lost-to-
follow-up and 14
had missed one of
the three
assessment
periods.
Therefore,
longitudinal
analysis was
performed on 58
eligible infants.
- Peabody
Developmental Motor
Scales at 18 months,
3 and 5 years of age
- Assessed fine and
gross motor
development
- Home Observation of the
Maternal Environment (HOME)
Scale
- Griffiths Mental
Developmental Scales
- No significant difference in gross or fine
motor development by sex
- Micropreemies, had significantly lower
gross and fine motor development at 5 year,
while infants from homes with low HOME
scores had lower gross and fine motor
development scores at 18 months and 5 year
of age
Gray et al.,
1999133
Prospective
cohort study
A sample of 84
consecutively
born neonates
with intrauterine
growth
restrictions and 81
appropriately
grown control
infants were
enrolled. Controls
were the next
appropriately
grown infants of
the same sex,
ethnic
background and
gestational age
- Neuro-Sensory
Motor Developmental
Assessment at 4
months of age
- Assessed fine and
gross motor
development
- Intrauterine growth restrictions
(birth weight more than 2 SDs
below mean for gestational age)
- Placental pathology
- Pregnancy history:
hypertension, diabetes mellitus,
alcohol, tobacco and drug use
during pregnancy, labour details,
fetal distress, baby’s condition at
birth and during the neonatal
period
- Infant birth weight, length,
head circumference, mid-arm
circumference
- Growth parameters: weight,
length, BMI, mid-arm
circumference, head
- Placental infarction and accelerated villous
maturation was significantly associated with
intrauterine growth restriction cases
- No significant difference across any
developmental domains on the Griffiths
Scale or the Neuro-Sensory Motor
Developmental Assessment between the
intrauterine growth restriction group and the
appropriately grown control group
89
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
and whose parents
were from
Brisbane.
circumference
- Griffiths Infant Development
Scale
Handal et
al., 2015134
Prospective
cohort study
A sample of
51404 singleton
pregnancies were
assessed from the
Norwegian
Mother and Child
Cohort Study
- Ages and Stages
Questionnaire at 3
years of age
- Assessed gross and
fine motor
development
- Exposure to selective serotonin
reuptake inhibitors (before and
during pregnancy)
- Depression before pregnancy,
- Hopkins Symptom Checklist:
test for anxiety and depression
- Parental characteristics: age,
education, marital status, parity,
planned pregnancy, maternal
work situation, maternal BMI,
maternal smoking, maternal
opioid (analgesic) and
benzodiazepine during
pregnancy and alcohol during
pregnancy
- Fine and gross motor development was
associated with parental education, paternal
age parity, maternal smoking, depression
before pregnancy and anxiety and
depression after pregnancy
- prolonged SSRI use increased the odds
ratio of lower fine motor development
- “weak” association between fine and gross
motor development and the use of selective
serotonin reuptake inhibitors during
pregnancy
Hanley et
al., 2013135
Prospective
cohort study
A sample of 31
mother-child pairs
exposed to
serotonin
reuptake
inhibitors and 52
mother-child pairs
unexposed.
- Bayley Scales of
Infant Development,
3rd edition at 10
months of age
- Assessed fine and
gross motor
development
- Serotonin Reuptake Inhibitor
expose
- Demographics, reproductive
and medical history, and
prescription medication history
- Neonatal outcomes: gestational
age, birth weight and length,
head circumference, and Apgar
scores
- Edinburgh Postnatal
Depression Scale for Depression
- Hamilton Rating Scale for
Depression
- Positive and Negative Affect
Scale
- Poor gross motor development scores were
observed among infants exposed to
serotonin reuptake inhibitors, when
controlling for depression during pregnancy
and at time of assessment, and alcohol and
tobacco use.
- Lower social-emotional and adaptive
behaviours were also reported by others of
exposed infants, controlling for maternal
mood at 36 weeks’ gestation and at 10
months postpartum, smoking and alcohol
use.
- No significant associations between any
developmental outcomes and maternal
depression
- Smoking during pregnancy was associated
with decreased expressive communication
scores at 10 months
90
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
Hanson et
al., 2011136
Cross-
sectional
study
A sample of 176
children aged 2-
34 months were
enrolled.
- Peabody
Developmental Motor
Scales, 2nd edition at a
mean age of 15.38
months (SD: 8.39
months)
- Assessed gross
motor development
(fine motor
development not
included)
- Growth Parameters: height,
weight and head circumference,
gender
- Chronological and gestational
ages
- Placement type (foster care,
kinship care, in-home protective
services; type of child welfare)
- Time with child welfare
- Number of placements
- Prenatal exposure to illicit
drugs
- Reason for placement: physical
or sexual abuse, neglect, medical
neglect, abandonment, housing
problems, parental substance
abuse, maternal mental illness,
abuse of siblings, maternal
incarceration or other
- Significant positive correlation between
weight-for-height and gross motor scores
- Compared to other reasons, children
involved with child welfare due to abuse or
neglect, medical neglect and parental
substance abuse had lower gross motor
quotients and those involved due to
abandonment had higher scores
- Significant differences between gross
motor quotient means between those
entering child welfare due to medical
neglect compared to all types of abuse or
neglect
- Significant difference in gross motor
quotient between those staying in kinship
care versus foster care, and those staying in
kinship care versus in-home protective
services (children in kinship care had
highest scores)
Keim et al.,
2011137
Prospective
cohort study
A subset of 358
infants were
recruited from the
Pregnancy,
Infection, and
Nutrition Study.
- Mullen Scales of
Early Learning at 12
months of age
- Assessed fine and
gross motor
development
- State-Trait Anxiety Inventory
- Centers for Epidemiologic
Studies Depression Scale
- Edinburgh Postnatal
Depression Scale
- Gestational age, income, pre-
pregnancy BMI, education,
social support, self-esteem,
maternal age, infant sex,
gestational age, presence of
spouse/partner, perceived stress
- Anxiety, stress and depression were
associated with younger maternal age, low
self-esteem, low income and low education.
Anxiety and depression were also associated
with low social-support, or absence of
spouse/partner. Depression was also
associated with higher BMI.
- Infant of older and more educated mothers
had higher fine motor scores. Preterm
infants had lower fine and gross motor
scores, and lower composite scores.
- Associations between trait anxiety,
perceived stress and depression with gross
motor development were U-shaped. Low
and high anxiety and depression were
associated with higher scores, whereas
moderate exposure was associated with
91
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
poorer scores.
- High depression scores were also
associated with better fine motor
development
- Perceived stress was positively associated
with cognitive ability and expressive
language ability
Kelly et al.,
2006138
Prospective
cohort study
A subset of 15994
children from the
Millennium
Cohort Study
were assessed.
- Adapted from the
Denver
Developmental
Screening Test at a
mean age 9.2 months
> Assessed fine
and gross motor
development
- Adapted from
McArthur
Communicative
Development
Inventory at mean age
9.2 months
> Assessed
communicative
gestures
- Ethnicity: Black Caribbean,
Black African, Bangladeshi,
Indian, Pakistani, White, other
- Biological: sex, gestational
age, parity, maternal age,
illnesses requiring doctor,
hospitalizations
- SES: income, overcrowding
(>1.5 people/room), damp in the
home, no heating
- Culture: language spoken at
home, maternal country of origin
- House: Lone parent, number of
siblings in the household,
grandparents in the household,
other adults living in the
household
- Interaction: maternal
employment status, other infant
carers, maternal Malaise
Inventory, maternal attitudes to
childcare
- Black African, Black Caribbean, Indian,
mixed ethnicity had the highest rates of
normal development
- Bangladeshi and Pakistani had the lowest
rates
- Black Caribbean infants were less likely to
have gross motor delays, but had normal
rates of fine motor and communicative
gestures delays
- Bangladeshi infants had only slightly
higher rates of gross motor delays, but
nearly twice the average levels of fine motor
delay
- White infants were used as reference group
as they were the largest category.
- In fully adjusted model, Indian, Black
Caribbean and Black African were
significantly less likely to have gross motor
delays
- No significant differences were observed
for fine motor development in the fully
adjusted model
Koutra et
al., 2013139
Prospective
cohort study
A subset of 470
mother-child
dyads were
assessed from the
Rhea Cohort
Study. Women
spoke Greek and
were older than
- Bayley Scales of
Infant Development,
3rd edition at 18
months of age
- Assessed fine and
gross motor
development
- Antenatal Psychological
Assessment
- Edinburg Postnatal Depression
Scale
- State-Trait Anxiety Inventory
- Eysenck Personality
Questionnaire-Revised
- Maternal mental health:
- High levels of antenatal maternal
depressive symptoms were associated with
decreased cognitive development
- Increasing anxiety or increased
extraversion was associated with increased
social-emotional development
- increased trait anxiety or neuroticism was
associated with increased expressive
92
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
17 years of age
with singleton
pregnancies.
antenatal depression, trait
anxiety, personality traits
- Potential confounders: sex,
quality of assessment, delivery
type, gestational age,
breastfeeding duration,
childcare, maternal age at
delivery, maternal education,
maternal origin (i.e. Greek vs
non-Greek), parity, employment
status
communication
- High postpartum depression was
associated with decreased cognitive and fine
motor development
Koutra et
al., 2012140
Prospective
cohort study
A subset of 605
infants from 593
pregnancies were
assessed from the
Rhea Cohort
Study. Women
spoke Greek and
were older than
17 years of age.
- Bayley Scales of
Infant Development,
3rd edition at 18
months of age
- Assessed fine and
gross motor
development
- Socio-demographic
characteristics: parental age,
education, origin, marital status,
parity, maternal employment
status, gestation age, type of
delivery and anthropometric
measurements at birth
- Cognitive development (univariate): sex,
preterm, singleton, siblings, ICU, maternal
education, paternal education, maternal
employment; (Multivariate better outcomes)
high maternal education, only child,
singleton, girl
- Receptive-communication: (univariate)
sex, preterm birth, siblings, hours with
father per day, maternal origin, paternal
origin, maternal and paternal education,
maternal employment (Multivariate better
outcomes) high maternal education, Greek,
maternal employment, only child, girl, not
preterm
- Expressive communication: (univariate)
sex, preterm birth, singleton, siblings, hours
per day with mother, maternal origin,
paternal origin, maternal and paternal
education, maternal employment
(Multivariate better outcomes) low maternal
age, high maternal education, Greek,
maternal employment, only child, girl,
increased birth weight, increased hours per
day with mother
- Fine motor: (univariate) sex, preterm,
singleton, ICU, maternal education,
93
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
maternal employment (Multivariate better
outcomes) high maternal education, Greek,
singleton, female
- Gross motor: (univariate) preterm,
siblings, ICU, maternal education, paternal
education, maternal employment
(Multivariate better outcomes) only child
- Social-emotional: (univariate) sex,
preterm, singleton, maternal education,
paternal education (Multivariate better
outcomes) medium or high maternal
education, singleton, female
Laucht et
al., 1997141
Prospective
cohort study
A subset of 350
infants were
assessed from the
Mannheim Study
of Risk Children.
- Bayley Scales of
Infant Development,
1st edition at 4.5 years
of age
- Assessed gross
motor development
- Biological risk: term status,
birth weight, medical
complications,
- Psychosocial risk: measure of
unfavorable familial
characteristic (i.e. low
education, crowded living,
parental psychiatric disorder,
parental delinquency, history of
broken home, marital discord,
early parenthood, single-parent
family, unwanted pregnancy,
lack of social support, severe
chronic difficulties, poor coping
skills
- Behavioral and emotional
assessment
- Children with complications of pregnancy
or delivery displayed delayed motor
development at all age periods
- Children suffering from pre- and perinatal
complications also performed more poorly
on the measures of cognitive development at
all age periods
- Poorer motor and cognitive functioning
was shown among children of
disadvantaged families
- Children with multiple (biological and
physiological risks) showed the most
favourable prognosis in all areas of
functioning
- Among the predictors of motor
development, complications during
pregnancy and neonatal period had the
greatest impact
- Low parental education was a significant
predictor of cognitive development delays.
Levantakou
et al.,
2013142
Prospective
cohort study
A subset of 540
mother-child
dyads were
assessed from the
Rhea Cohort
- Bayley Scales of
Infant Development,
3rd edition at 18
months of age
- Breastfeeding: initiation,
duration, use of formula,
complementary food
- Edinburgh Postnatal
Depression Scale
- Mothers were more likely to breastfeed
their child longer if they were older, had a
university degree, did not smoke during
pregnancy or after birth
- Longer duration of breastfeeding was also
94
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
Study. Women
spoke Greek and
were older than
16 years of age
with no
communication
handicap. Only
singleton
pregnancies
included
- Assessed fine and
gross motor
development
- Parental characteristics:
maternal and paternal age,
education, origin, maternal
working status, marital status,
parental smoking during
pregnancy and postpartum,
- Perinatal and infant
characteristics: sex, type of
delivery, siblings, birth order,
birth weight, head
circumference, gestational age,
preterm birth, NICU, day care
attendance, hours per day with
mother or father, age of
introduction of solid foods
positively associated with paternal age,
paternal high education, paternal non-
smoking during or after pregnancy
- Crude analysis found that breastfeeding
was associated with higher cognitive,
receptive communication and fine motor
scores
- Duration of breastfeeding was positively
associated with higher scores in all
developmental measures except gross motor
in adjusted models
- Children who were breastfed longer than 6
months had higher fine motor scores in
adjusted models
95
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
Long et al.,
2016143
Prospective
cohort study
A sample of 33
children were
recruited.
Children
underwent cardiac
surgery in the first
2 months of life,
had no known
chromosomal
abnormalities or
congenital
syndromes, and
their families
spoke English and
lived >100km
outside
Melbourne
metropolitan area.
- Alberta Infants
Motor Scale at 4, 8,
12, and 16 months of
age
- Assessed gross
motor development
- Bruininks-Oseretsky Test of
Motor Proficiency Brief Form,
2nd edition
- Pediatric Clinical Test of
Sensory Interaction
- Range of movement and leg
length
- Bayley Scales of Infant
Development, 3rd edition at 2
years
- Social Risk Index: family
structure, education of the
primary caregiver, occupation,
employment status and income
of primary earner, language
spoken at home and maternal
age at delivery
- Covariates: gestational age,
birth weight, cardiopulmonary
bypass time, respiratory support
time, ICU length of stay, sex,
cyanotic CHD, single or
biventricular circulation, arch
repair, reciprocal or
asymmetrical crawl pattern
- 41% of patients who underwent early
cardiac surgery had below-average motor
proficiency at 5 years of age
Majnemer et
al., 2006144
Prospective
cohort study
A sample of 83 4-
month old and 72
6-month old
infants were
recruited. Infants
were excluded if
they were <38
weeks’ gestation,
their parent did
not speak English
or French, they
had torticollis,
- Alberta Infant
Motor Scale at 4 or 6
months
>Assessed gross
motor development
- Peabody
Developmental Motor
Scales
> Assessed fine
and gross motor
- Sleep position
- Awake position
- Demographics: weight, sex,
parity, breastfeeding, maternal
smoking, parents’ age, education
- Potential confounders: weight
at assessment, parity, parental
age and education, sex and age
at testing
- Prone AIMS score was significantly higher
among infants sleeping in the prone position
at 4 months of age. There was no difference
between the prone and supine group on the
PDMS at 4 months.
- Infants sleeping in the prone position had
higher scores on the prone, supine,
percentile and total score of the AIMS and
higher gross motor score on the PDMS
compared to infants sleeping in the supine
position at 6 months.
- At 15 months of age there were not
96
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
prenatal or
perinatal
complications or
attending day care
where positioning
practices less
consistent.
development
- Battelle
Developmental
Inventory at 15
months of age
significant differences between the supine
and prone sleep-position groups on motor
performance or overall developmental
scores
- Infants put to sleep in the prone position
were more likely to spend more time awake
in the prone position and spend less time
being held than those sleeping in the supine
position at 6 months of age.
- At 4 months, mean daily exposure to prone
position when awake, mean exposure to
supported sitting position and parents age
was correlated to AIMS scores
- At 6 months, awake prone time was
correlated with AIMS scores and gross
motor PDMS scores. Gross motor scores
were associated with sitting exposure. In
adjusted models, sleep position consistently
predicted AIMS and PDMS gross motor
scores.
- At 15 months, sleep position continued to
predict motor performance
Majnemer et
al., 2005145
Cross-
sectional
study
A sample of 71 4-
month old and 50
6-month old
infants were
assessed. Infants
were excluded if
they were <38
weeks’ gestation,
their parent did
not speak English
or French, they
had torticollis,
prenatal or
perinatal
complications or
- Alberta Infant
Motor Scale at 4 or 6
months
>Assessed gross
motor development
- Peabody
Developmental Motor
Scales
> Assessed fine
and gross motor
development
- Sleep position
- Awake position
- Demographics: weight, sex,
parity, breastfeeding, maternal
smoking, parents’ age, education
- Potential confounders: weight
at assessment, parity, parental
age and education, sex and age
at testing
- At 4 months of age: AIMS centiles
positively correlated with prone awake time
and negatively correlated with maternal and
paternal age. PDMS fine motor scores
positively correlated with supported sitting
time and age at testing, and negatively
correlated with prone awake time and
parents’ education. Gross motor scores were
positively correlated with age at testing.
- At 6 months of age: AIMS centiles
positively correlated with prone awake time.
PDMS fine motor scores positively
correlated with prone awake time. Gross
motor scores were positively correlated with
prone awake time and supported sitting
97
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
attending day care
where positioning
practices less
consistent.
time, and negatively correlated with paternal
age.
McGrath &
Sullivan,
1999146
Prospective
cohort study
A sample of 108
4-year old
children and their
mothers were
enrolled. Mothers
were English-
speaking, older
than 16 years of
age, had no
psychiatric
history and denied
drugs and
substances abuse.
- Riley Motor
Problems Inventory at
4 years of age
> Assessed oral
motor and fine motor
development
- Beery Visual-Motor
Integration Test at 4
years
> Assessed Visual-
Motor development
- McCarthy Scales of
Children’s Abilities at
4 years of age
> Assessed general
motor development
(author argues is a
good indicator of
gross motor
development)
Proximal Measures:
- Maternal Self-Esteem Scale
- Perception of Child Health
- Beck Depression Inventory
- Home Observation for
Measurement of the
Environment Preschool Version
- Parent/Caregiver
Involvement Scale
- Problem Solving Scale
Distal Measures:
- Family Resource Scale
- Family Support Scale
- Family Functioning Scale
- Life Events Questionnaire
- Hollingshead Four-Factor
Index of Social Status
Child Measures:
- EAS Temperament Survey
of Children: Parental Ratings
- Behavioural Style
Assessment
- Medical Risk Score
- Fine motor development significantly
lower among preterm infants with medical
conditions or neurological compromise than
compared to full-term or healthy preterm
infants.
- Full-term infants scores higher on visual-
motor integration than compared to any
preterm group (healthy preterm, small-for-
gestational age preterms, sick preterms, or
preterms with medical complications or
neurologic compromise.
- The percentage of children with motors
delays was fewest among the full-term
infants (5%-17%)
- Hierarchical multiple linear regressions:
- Oral motor: child measures were the
only significant predictor. Proximal and
distal measures not independently
significant
- Fine motor: Proximal and child
measures significant predictors
- Gross motor: proximal, distal and child
measures were significant predictors
- Visual-motor: proximal and child
98
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
measures were significant predictors
McDonald
et al.,
2014147
Prospective
cohort study
A sample of 159
Aboriginal infants
were recruited.
- Griffiths Mental
Development Scales
– Extended Revised
at 1 and 3 years of
age
- Assessed fine and
gross motor
development
- Peabody Picture Vocabulary
Test, 4th edition
- Study factors: sex, suburb of
residence, parity, maternal age,
maternal education, marital
status, mother was in foster care,
primary care giver not mother,
preschool/day care
- Socio-economic Indexes for
Areas
- Kessler-5 depression scale
(primary care giver)
- Bivariate risk factors for GMDS-ER:
maternal age <20 years, low maternal
education, single mother
- Multivariate risk factors for GMDS-ER:
maternal age <20 years, single mother
Michalowicz
et al.,
2011148
Randomized
Control Trial
A sample of 411
women were
recruited from the
Obstetrics and
Periodontal
Therapy Trial.
- Bayley Scales of
Infant Development,
3rd edition at 24-28
months of age
- Assessed fine and
gross motor
development
- Preschool Language Scale, 4th
edition
- Infant characteristics: history
of seizures, trauma, ventilator
use, steroid use, lead and
hematocrit levels
- Family history: history of child
care, parent education, health-
related behaviours, Home
Observation for Measurement of
the Environment (HOME)
Inventory, emotional and verbal
responsiveness of the
mother/primary caregiver,
avoidance of restriction and
punishment, organization of the
physical and temporal
environment, provision of
- Mean cognitive, motor and language
scores did not differ significantly between
treatment and control groups in unadjusted
or adjusted analyses
- Explanatory variables that were significant
in multiple linear regression analysis:
- Cognitive development: Clinic
- Motor development: Clinic, gestational
age at delivery, 5-minute Apgar score, head
circumference <10 percentile, primary
caregiver’s education
- Language: head circumference <10
percentile, HOME inventory
99
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
appropriate play material,
maternal involvement with the
child, and variety in daily
stimulation
Miller-
Loncar et
al., 200485
Prospective
cohort study
A subset of 392
cocaine exposed
and 776
unexposed infants
from the Maternal
Lifestyle Study
were assessed.
- NICU Network
Neurobehavioral
Scale (NNNS) at 1
month of age
> Assessed general
motor development
(combined composite
score)
- Posture and Fine
Motor Assessment of
Infants (PFMAI) at 4
months of age
> Assessed
postural and fine
motor development
(combined into
composite score)
- Bayley Scales of
Infant Development,
2nd edition at 12
months of age
> Assessed general
motor development
- Peabody
Developmental Motor
Scales at 18 months
of age
> Assessed general
motor development
- Maternal Inventory of
Substance Abuse (timing and
amount of cocaine, alcohol,
nicotine, and marijuana used
during pregnancy
- Hollingshead Index of Social
Position
- Covariates: SES, birth weight,
race, study site
- Prenatal cocaine exposure was
significantly associated with poorer motor
skills.
- Prenatal cocaine exposure interacted with
age, where infants exposed to cocaine
displayed a faster rate of increase in motor
skills than the comparison group
- Study site, birth weight and heavy tobacco
use was also associated with motor
development
- Heavy prenatal exposure to cocaine was
associated with poorer motor scores
compared to unexposed infants. There was
not a significant difference based on level of
exposure for change over time, however.
100
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
(combined into
composite score)
Nelson et
al., 200490
Prospective
cohort study
A sample of 143
2-year old and
274 4-year old
children were
enrolled.
- Bayley Scales of
Infant Development,
1st edition at 2 years
of age
>Assessed general
motor development
- Peabody
Developmental Motor
Scales at 4 years of
age
> Assessed fine
and gross motor
- Cocaine, marijuana, tobacco,
alcohol exposure
- Peabody Picture Vocabulary
Test-Revised
- Brief Symptom
Inventory/Global severity Index
- Maternal characteristics: race,
age, SES, gravida, parity,
number of prenatal care visits
- Infant Measures: birth
outcomes, Apgar scores, Hobel
Neonatal Risk Index
- Hematologic assessment:
hemoglobin, mean corpuscular
volume, transferrin saturation,
serum ferritin, lead, iron status
- Environmental measures:
Home Observation of the
Environment (HOME) Inventory
Neurodevelopment: Wechsler
Preschool and Primary Scales of
Intelligence
- Correlations with motor development:
- 2-year psychomotor: ethnicity, parity,
maternal education, sex
- 4-year gross motor: parity, maternal IQ
(PPVT-R), birth weight, head
circumference, Hobel risk score, gestational
age
- 4-year fine motor: parity, maternal
education, sex, nonmaternal care
- Full Scale IQ was predicted by iron
deficiency anemia and lead levels
- Verbal IQ was predicted by HOME scores
- Performance IQ was predicted by maternal
IQ, cocaine exposure and lead
Nervick et
al., 2011149
Cross-
sectional
study
A convenience
sample of 50
children between
3-5 years of age
were enrolled.
Children were
typically
developing health,
enrolled in day
care and free from
medical,
orthopedic or
neurological
- Peabody
Developmental Motor
Scales, 2nd edition at
3-5 years of age
- Assessed fine and
gross motor
development
- Anthropometric tests: child’s
height, weight, BMI
- Significant correlation between BMI sets
and gross motor quotient
- Stepwise hierarchical regression analysis
found that neither gender nor age nor BMI
sets made a significant contribution to the
linear regression model
101
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
conditions that
could affect
performance in
gross motor skills
Oddy et al.,
2011150
Prospective
cohort study
A sample of 2868
children involved
in the Western
Australian
Pregnancy Cohort
(Raine) Study.
- Infant/Child
Monitoring
Questionnaire (a.k.a.
Ages and Stages
Questionnaire) at 1, 2
and 3 years of age
- Assessed fine and
gross motor
development
- Questionnaire collecting
information on parental
sociodemographic factors
(housing, family structure,
employment and income),
family functioning,
neurodevelopment, behaviour
and history of illnesses, injuries
and admissions to hospital
- Predictor measure:
breastfeeding
- Confounding factors: maternal
age, education, smoking during
pregnancy, biological father
presence, family income, total
number of stressful life events
experienced during pregnancy,
child’s Apgar scores, gestational
age, sex
- Infants who had breastfed for >4 months
had significantly higher scores on fine
motor and communication development at
1, 2 and 3 years compared to infants who
breastfed for <4 months. Moreover, infants
who had breastfed for >4 months also had
significantly higher scores on adaptability at
1 and 2 years compared to infants who
breastfed for <4 months.
- The results of multinomial logistic
regression analyses showed that
breastfeeding for <4 months significantly
increased the risk for two or more atypical
scores across all domains over the 3 years of
the study except for gross motor skills.
Piteo et al.,
2012151
Prospective
cohort study
A sample of 360
infants were
recruited from the
control group of
the DOMInO
trial. Women
were given
vegetable oil
capsules without
DHA.
- Bayley Scales of
Infant Development,
3rd edition at 18
months of age
- Assessed fine and
gross motor
development
- Edinburgh Postnatal
Depression Scale (at 6 weeks
and 6 months postpartum)
- Baseline characteristics:
maternal age, medical diagnosis
of previous or current
depression, current treatment for
depression, social support
(Maternal Social Support Index),
education and occupation
- Home Screening Questionnaire
(HSQ)
- Adjusted models controlled
for: preterm birth, maternal
- No significant differences between
maternal depression and child cognitive,
language or motor development at 18
months of age in unadjusted or adjusted
analysis
- Home environment was a significant
predictor of each developmental outcomes
after adjusting for demographic variables
- Maternal occupation, maternal secondary
education, maternal further education, and
infant feeding at 6 months of age were
significant predictors of cognitive
development in adjusted models
- No demographic variables had a
102
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
occupation, maternal secondary
education, maternal further
education, history of depression,
home environment, maternal
social support, and infant
feeding at 6 weeks and 6 months
of age
significant effect on motor development in
either adjusted or unadjusted analyses
Richardson
et al.,
1995152
Prospective
cohort study
A sample of 829
women were
enrolled. Women
were selected
from two ongoing
cohort studies: a
study on alcohol
consumption
during pregnancy
and a study on
marijuana
consumption
during pregnancy.
- Bayley Scales of
Infant Development,
3rd edition at 9 and 19
months of age
- Assessed fine and
gross motor
development
- Alcohol and marijuana
exposure
- Tobacco and other drug use
during pregnancy
- Gestational age,
- Maternal medical history,
pregnancy (anemia, maternal
infections, hypertension,
abnormal bleeding), labour
(precipitous labour, induction,
Pitocin augmentation and
premature labour) and delivery
conditions (anesthesia,
meconium stained fluid, nuchal
cord, cesarean section and
forceps delivery)
- PROCESS Scale
- HOME Inventory
- In regression analyses, prenatal alcohol
and tobacco use did not predict
psychomotor or mental development at 9
months
- Third trimester marijuana use predicted
lower mental development at 9 months
- At 19 months of age, prenatal alcohol,
marijuana or tobacco use did not predict
psychomotor or mental development scores
- Variance in mental development was
explained by number of toys in the house,
developmental stimulation, sex, race, age
examiner, SES, psychosocial and family
configuration
- Current tobacco use was a predictor of
mental development at 19 months
- ANCOVA analysis of differing duration of
exposure to alcohol or marijuana did not
find any significant difference in mental or
motor development
- Infants exposed to one or more packs of
cigarettes per day during pregnancy
exhibited significantly lower mental
development scores than offsprings of non-
smokers
- Adjusted analysis for duration/degree of
exposure:
- No significant difference in
development scores between differing
degrees of alcohol exposure
103
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
- Significantly lower scores were
exhibited by infants of mothers smoking 1
or more joints per during the third trimester,
compared to infants of nonsmokers or
moderated marijuana users
- Infants exposed to one or more packs
of cigarettes per day during the first
trimester exhibited significantly lower
mental development scores than offsprings’
of non-smokers
Saraiva et
al., 2013153
Cross-
sectional
study
A sample of 367
children were
enrolled in the
study. They were
divided into three
age groups: 3-
year-olds (122),
4-year-olds (130)
and 5-year-olds
(115). Children
had no
intellectual,
physical or
emotional
disabilities.
- Peabody
Developmental Motor
Scales, 2nd edition
- Assessed fine and
gross motor
development
- Child characteristics: height,
weight, BMI (all converted to
age-appropriate z-scores
according to WHO Child
Growth Standards
-
- Sex differences: Boys showed higher
scores on object manipulation at 3, 4 and 5
years, whereas girls showed higher scores
on grasping and visual-motor integration at
3 and 4 years of age
- Grasping: Age and sex predictor variables
at 3 and 4 years. Height for age predictor at
5 years.
- Visual-motor integration: age a predictor
at 3, 4 and 5 years. Sex a predictor at 3
years.
- Stationary: age a predictor at 3, 4 and 5
years. Height-for-age a predictor at 3 years,
and BMI-for-age a predictor at 5 years.
- Locomotion: Age a predictor at 3 and 4
years
- Object manipulation: age and sex a
predictor at 3, 4 and 5 years. Weight-for-age
a predictor at 4 years.
Scher et al.,
200899
Prospective
cohort study
A convenience
sample of 142
infants were
assessed. Infants
were participating
in the Training
and Outcomes for
Early
- Harris Infant
Neuromotor Test
(HINT) at 4-6 and 10
12 months of age
- Assessed general
motor development
***NOTE: lower
score indicates better
- Infant Sleep Questionnaire
- HINT scores were not associated with
scores from the Infant Sleep Questionnaire
- Parental perception of child’s sleep
difficulty was associated with child
neurodevelopment at 10-12 months of age,
but not at 4-6 months of age
- Severity of sleep difficulties significantly
decreased with age in the “no-risk group”
104
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
Identification of
Infants with
Neuromotor
Delays. Infants
were born at term
(>37 weeks’
gestation),
weighed >2500
grams, and had no
postnatal infant
health problems
or congenital
anomalies.
development***
- Alberta Infant
Motor Scale 4-6 and
10 12 months of age
- Assessed general
motor development
- Ages and Stages
Questionnaire at 4-6
and 10 12 months of
age
- Assessed fine
and gross motor
development
and the “low risk group”, but not in the
“high risk group”
- In the low-risk group, sleep difficulties
decreased with age, whereas in the high-risk
group, sleep disruption increased over time
Smith et al.,
2011154
Prospective
cohort study
A sample of 412
mother-infant
dyads were
recruited into the
IDEAL Study.
204 infants were
exposed to
methamphetamine
prenatally, while
208 infants were
non-exposed.
- Peabody
Developmental Motor
Scale at 12 and 36
months of age
>Assessed gross
and fine motor
development
- Bayley Scales of
Infant Development,
2nd edition at 12, 24,
36 months of age
- Assessed general
motor development
- Methamphetamine exposure:
self-report and meconium screen
- Lifestyle Interview: number of
prenatal visits, age, education,
occupation, race, marital status,
type of insurance, SES
(Hollingshead Index), licit and
illicit drug use, alcohol, tobacco
and marijuana
- Substance Use Inventory
- Peabody Picture Vocabulary
Test, 3rd edition
- Home Observation for
Measurement of the
Environment (HOME) Inventory
- Methamphetamine exposure was
associated with lower scores on the grasping
subtest at 1 year, but not at 3 years.
Moreover, heavy methamphetamine use was
associated with lower grasp scores than
some methamphetamine exposure or no
exposure
- No significant difference between
methamphetamine exposure of mental or
psychomotor development were found
- After adjusting for birth weight, prenatal
drug exposure and SES, grasping scores
were lower in children with prenatal
methamphetamine exposure
- Low SES was associated with low fine
motor development
- No significant difference between
methamphetamine exposure and fine or
gross motor development
- Maternal IQ and quality of home were
associated with mental development, but not
motor development
105
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
- Both motor and mental development was
lower among boys than girls
Sommerfelt
et al.,
1996155
Cross-
sectional
study
A sample of 144
5-year old low-
birth weight
children were
compared to 163
normal birth
weight children.
- Peabody
Developmental Motor
Scales at 5 years of
age
- Assessed fine and
gross motor
development
- Feeding practices
- Intrauterine growth restrictions
- Infant Characteristics:
gestational age, birth weight,
head circumference, birth length
- Cranial ultrasound: cerebral
hemorrhage
- Parental factors: parental
education, total family income,
maternal smoking, single-parent
family status
- Abnormal balance scores, presences of
motor problems and abnormal minor
neurology scores were significantly more
common in low-birth weight boy than
normal birth weight
- Abnormal eye-hand coordination and leg
neurology scores were significantly more
common in low birth weight girls
- For low-birth weight boys, there was an
increased risk of abnormal balance scores
and of having a motor problem when the
infant received predominantly formula
compared to breastmilk or breastmilk and
formula
- For the low-birth weight girls, none of the
pre-, peri- or post-natal factors were
predictive of abnormal scores on the eye-
hand coordination or leg neurology scales
Tirosh et al.,
1991156
Cross-
sectional
study
A sample of 59
children with no
known
neurological,
genetic or
cognitive
problems were
evaluated. Among
the sample, 20
infants had joint
hypermobility and
delayed motor
development, 19
infants had joint
hypermobility and
normal
development, 20
- Hoskins-Squires test
for gross motor and
reflex development at
54-60 months of age
> Assessed gross
motor development
- Bruininks-Oseretsky
pegboard test/block
tower/Beery-
Buktenica visual-
motor integration test
at 54-60 months
> Assessed fine
motor development
- Parent perception of motor
proficiency
- Conner’s parent rating scale
- Prevalence of gross motor delays at 5
years of age among infants had joint
hypermobility and delayed motor
development were higher than in the other
two groups
- Children who presented with joint
hypermobility and motor delays at 18
months were significantly more likely to
present the same association when they
reached 5 years of age
- Infants had joint hypermobility and
delayed motor development showed
significant disadvantages in the pegboard
test
- No differences were found in the visual-
motor integration test
- No differences were found in perceived
106
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
were normal
controls.
behaviour by the Conner’s rating scale
Torsvik et
al., 2015157
Prospective
cohort study
A sample of 97
healthy infants
and their mothers
were
consecutively
recruited.
- Alberta Infant
Motor Scale at 6
months of age
> Assessed gross
motor development
- Ages and Stages
Questionnaire at 6
months of age
> Assessed fine
and gross motor
development
- Gestational age was based on
ultrasonography
- Maternal and infant nutrition
and vitamin supplementation
- Blood samples collected from
infant and mother (assessed
cobalamin)
- Breastfeeding/feeding practices
- Cobalamin intervention
- Strongest determinant of infant vitamin B
status at 6 months was duration (months) of
exclusive breastfeeding, where those
breastfed
> Vitamin B status at 6 months showed a
linear, inverse relationship with duration of
exclusive breastfeeding
- Formula fed infants had a significantly
higher median AIMS score than breastfed
infants
- Duration of exclusive breastfeeding was a
significant negative predictor of AIMS score
in a multiple linear regression model
adjusted for gender, SGA, infant weight,
maternal education, and folate and iron
supplementation
- The breastfed infants had significantly
lower median gross motor scores
- No significant difference was observed for
communication, personal-social functioning
and problem solving skills
Tsuchiya et
al., 2012158
Prospective
cohort study
A subset of 742
infants enrolled in
the Hamamatsu
Birth Cohort were
assessed.
- Mullen Scales of
Early Learning at 6,
10 and 14 months
- Assessed gross
motor development
- Season of birth: Winter
(December, January, February),
Spring (March, April, May),
Summer (June, July, August),
Fall (September, October,
November)
- Demographic information:
maternal age, paternal age,
parity, household annual income
- Perinatal variables: gestational
age, birth weight, date and time
of birth
- Predicted gross motor scores at 6 months
of age peaked among March- and April-
born infants, and was lowest among
September- and October-born infants
- Gross motor scores peaked among
February-born infants at 10 months of age
- The difference in gross motor scores
between 6 and 10 months of development
peaked among December- and January-born
infants
- The difference in gross motor scores
between 10 and 14 months of development
107
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
- Breastfeeding status at
examinations
peaked among July- and August-born
infants
Veiby et al.,
2013159
Prospective
cohort study
A subset of 78744
mother-infant
dyads were
assessed from the
Norwegian
Mother and Child
Cohort Study.
- Ages and Stages
Questionnaire at 6
and 18 months of age
- Assessed fine and
gross motor
development
- Parental epilepsy
- Antiepileptic drug exposure
(monotherapy and polytherapy)
- Breastfeeding practices
- Gestational age, birth weight,
congenital malformations,
- Adjusted models for maternal
age, parity, education, folate
supplementation, smoking,
depression/anxiety,
breastfeeding, child
malformations
- Children exposed to antiepileptic drugs
had an increased risk of having lower fine
motor scores than unexposed children
- Children of mothers treated with the
polytherapy had an increased risk of poor
fine motor development compared to
unexposed children. There was no increased
risk among children exposed to the
monotherapy compared to unexposed
children
- Children of fathers with epilepsy did not
exhibit significant delays across any of the
developmental outcomes
- Continuous breastfeeding during the first
6-months was associated with a tendency
toward improved outcome for all
developmental outcomes, regardless of
antiepileptic exposure
Velikos et
al., 2015160
Prospective
cohort study
A sample of 120
of premature
infants.
- Bayley Scales of
Infant Development,
3rd edition at 12
months of age
- Assessed fine and
gross motor
development
- Demographic information:
gestational age, birth weight,
gender, premature rupture of
membranes, antenatal steroids,
mode of delivery, small-for-
gestational-age
- Medical interventions:
surfactant administration,
mechanical ventilation, duration
of oxygen therapy, total
parenteral nutrition, number of
blood transfusions
- Prematurity complications:
patent ductus arteriosus, sepsis,
necrotizing enterocolitis,
intraventricular hemorrhage,
- Fine motor development: (Bivariate
analysis) – associations with gender,
abnormal head ultrasound, total parenteral
nutrition, small-for-gestational age
(multivariable analysis) - associations with
gender, abnormal head ultrasound, small-
for-gestational age
- Gross motor development: (Bivariate
analysis) – associations with abnormal head
ultrasound, duration of oxygen therapy,
blood transfusions, invasive mechanical
ventilation; (multivariable analysis) –
associations with duration of oxygen
therapy
108
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
bronchopulmonary dysplasia,
retinopathy of prematurity,
cystic periventricular
leukomalacia
Wouldes et
al., 2014118
Prospective
cohort study
A subset of 103
methamphetamine
exposed infants
and 107 non-
exposed infants
were assessed
from the New
Zealand Infant
Development,
Environment and
Lifestyle study.
- Bayley Scales of
Infant Development,
2nd edition at 1,2 and
3 years of age
> Assessed general
motor development
- Peabody
Developmental Motor
Scale, 2nd edition at 1
and 3 years of age
>Assessed fine
and gross motor
development
- Substance use inventory:
quantity and frequency of
prenatal drug use
- Current household structure,
SES, quality of home
environment
- Peabody Picture Vocabulary
Test, 3rd edition
- Covariates: gender, birth
weight, ethnicity, drug use, SES
- No effects of methamphetamine exposure
on gross or fine motor development at 1
year of age
- At 3 years of age, gross motor
development was significantly lower among
infants exposed to prenatal
methamphetamine compared to non-
exposed infants
- At 1 and 2 years of age, methamphetamine
exposed was associated with lower
psychomotor scores compared to non-
exposed infants
-
Wylie et al.,
2015161
Prospective
cohort study
A subset of 4901
mother-infant
pairs were
assessed from the
Upstate KIDS
study.
- Six gross motor
milestones: sitting
without support,
standing with
assistance, hands-
and-knees crawling,
walking with
assistance, standing
alone, walking alone
- Used WHO 90th
centile’s
- Maternal BMI, paternal height
and weight, obstetrical
outcomes, sociodemographic
characteristics, SES, medical
insurance, plurality
- Smoking status and alcohol use
before and during pregnancy
- Gestational age, small-for-
gestational age, sex, birth weight
- Infants of mothers who were obese prior to
pregnancy were found to have a
significantly lower risk of achieving the
motor milestones of sitting without support
and crawling on hands-and-knees (achieved
milestones later)
- Children born to obese mothers had higher
odds of delay in walking compared to
children born to mothers with normal BMI
- Infants born to mothers with less than a
high school education or its equivalent were
slower to achieve standing with assistance,
walking with assistance, and walking alone
compared to infants with mothers with an
advanced degree
Yeung et al.,
2016162
Prospective
cohort study
A subset of 4824
mother-child
dyads were
assessed from the
- Ages and Stages
Questionnaire at 4, 6,
8, 12, 18, 24, 30 and
36 months of age
- Infertility Treatment Exposure
- Covariates: maternal and
paternal age, insurance status,
plurality, previous live birth,
- No statistically significant differences
were observed for any of the five
developmental domains assessed when
adjusting for birth weight and plurality
109
Author
(Year)
Study
Design
Study
population
Neurodevelopment
Test Factors investigated Results related to motor development
Upstate KIDS
study.
- Assessed fine and
gross motor
development
pre-pregnancy BMI, paternal
BMI, marital status, ethnicity,
education, smoking and alcohol
use during pregnancy
- Frequency of any disability did not differ
by infertility treatment exposure
110
2.2.2.1 Sociodemographic factors
Many of the previously described associations between socio-demographic factors and
general motor development have also been investigated with respect to fine and gross motor
development. For example, in their analysis of a sample of 356 children from the IDEAL study
in the US, Smith et al. found that SES, classified using the Hollingshead Four-Factor Index of
Socioeconomic Status, influenced fine motor development, but not gross motor development154.
Similar results were also found in Nelson et al.’s study, when marital status was used as a proxy
measure for SES90.
Other proxy measures for SES, such as maternal education have been shown to exhibit
different associations with fine and gross motor development. For instance, Koutra et al.
suggested that twins and children of mothers with low educational attainment exhibited lower
fine motor developmental scores compared with children of educated mothers140. Contrary to the
results by Koudra et al.140, however, Nelson et al., reported that maternal education was neither
associated with fine nor gross motor development90. Furthermore, Nelson et al. found that lower
maternal IQ, measured using the Peabody Picture Vocabulary Test-Revised, was associated with
poorer gross motor development.
The effect of parental age and a child’s sex revealed similar results to the data described
in the assessment of general motor development. Higher maternal120 and paternal120,134,138 age
were associated with poorer fine and gross motor development. Moreover, males exhibited lower
scores in fine motor development90,138,140. Gross motor development, however, did not differ
between males and females90,128,140.
Sociodemographic factors were shown to influence fine and gross motor
development90,120,130,138,140,154 in a similar pattern as general motor development. Given the
111
difference in the influence of sex on fine and gross motor development, however, updating
previous recommendations for controlling for sex when assessing factors influencing motor
development may be required when analyzing contemporary data.
2.2.2.2 Maternal health factors
Compared with studies interested in general motor development, few studies have
separated the influence of maternal physical health on child fine or gross motor development. Of
the limited number of studies, Wehby et al. investigated the association between folic acid
supplementation during pregnancy and fine and gross motor outcomes at 3 years of age 117. In
their analysis, they reported an association between folic acid supplementation during pregnancy
and increased gross motor scores during their follow-up of 6,774, singleton pregnancies.
Conversely, their analysis also revealed that calcium supplementation during pregnancy was
associated with lower gross motor development scores. No associations were found for fine
motor development.
Contrary to maternal physical health, the effect of maternal mental health on fine and
gross motor development has been well investigated. For example, in their aforementioned
study, Handal et al. reported that depression prior to pregnancy was associated with fine and
gross motor development delays in their analysis of the effects of selective serotonin reuptake
inhibitors on motor development of Norwegian children134. It was also reported, however, that
anxiety before pregnancy, and depression or anxiety during pregnancy were not associated with
fine or gross motor development in three year old children. Finally, Handal et al.’s analysis also
revealed that treatment with selective serotonin re-uptake inhibitors during pregnancy was
112
associated with delays in both fine and gross motor development in children of three years of
age.
Other drug exposures during pregnancy have also been investigated, with conflicting
results90,120-122,127,129,130,133,134,154. To understand motor development of infants prenatally exposed
to cocaine, Arendt et al. recruited infants into a 2-year longitudinal follow-up study120 where
information on maternal drug use was collected using the Maternal Postpartum Drug Interview.
Assessment of 98 cocaine-exposed and 101 unexposed infants revealed that cocaine exposure in
the first trimester of pregnancy was associated with poorer fine and gross motor development at
2 years of age. Furthermore, Arendt et al. also described that alcohol consumption in the month
prior to pregnancy or during the first trimester was also significantly associated with delayed
gross motor development. Marijuana exposure of any frequency at any point during pregnancy,
however, was not associated with motor development.
Similar results were also obtained in Handal et al. and Smith et al. analyses. Handal et al.
described that maternal self-report of cigarette consumption was associated with both fine and
gross motor development delays134. Additionally, Smith et al. found that children of the 204
pregnant women whose methamphetamine exposure was validated using meconium screening
had an increased risk of poor scores on a grasping subtest of the Peabody Developmental Motor
Scales (grasping score among exposed: 9.38, SD:1.66; scores among non-exposed: 10.51,
SD:1.97; p=0.024)154. Fine and gross motor development subscales, however, were not
associated with methamphetamine consumption during pregnancy.
Conflicting results for the consumption of alcohol, cigarettes, marijuana and cocaine,
however, are presented by Nelson et al90. In their analysis, maternal self-report of cocaine,
113
marijuana, tobacco and alcohol consumption was not associated with fine or gross motor
development.
The best quality of evidence suggest that folic acid supplementation, depression, and
prenatal drug use are associated with fine and gross motor development. Together, these studies
suggest that maternal physical and mental health must be considered when assessing the child’s
risk of later developmental delays.
2.2.2.3 Pregnancy and birth outcome factors
Similar to the analysis of birth outcomes and general motor development, studies
investigating the influence of birth outcomes on fine and gross motor development have largely
focused on gestational age and birth weight120,122,123,125,127,129,130,131,133,135-139,142,143,150,155,157,158.
Using data from a prospective cohort study of 10,748 singleton Irish infants Cruise et al.
described that low gestational age (25-26 weeks gestation: OR:2.06, 95%CI: 1.60-2.65; 37-41
weeks gestation: reference; 42-46 weeks gestation: OR:0.95, 95% CI:0.79-1.15) and birth weight
(<2500g: OR:1.72, 95%CI:1.28-2.31; 2500-3000g: OR:1.18, 95% CI:0.99-1.41; 3001-3500g:
reference; 3501-4000g: OR:0.85, 95% CI:0.74-0.97; >4000g: OR: 0.94, 95% CI:0.79-1.12) were
shown to be significantly associated with delays in gross motor development125. Fine motor
development, was also shown to be significantly associated with gestational age (25-26 weeks
gestation: OR:1.86, 95%CI: 1.40-2.49; 37-41 weeks gestation: reference; 42-46 weeks gestation:
OR:0.90, 95% CI:0.72-1.13) but not birth weight(<2500g: OR:1.34, 95% CI:0.96-1.88; 2500-
3000g: OR:0.99, 95% CI:0.80-1.22; 3001-3500g: reference; 3501-4000g: OR:0.90, 95% CI:0.76-
1.06; >4000g: OR: 0.81, 95% CI:0.65-1.02)53.
114
The literature investigating the effect of birth outcomes on fine and gross motor
development is limited. Though the effects of gestational age and birth weight53 are well
supported, few additional factors have been directly investigated.
2.2.2.4 Child health factors
Though many childhood health conditions may affect motor development, few have been
investigated for their influence on fine or gross motor development. Among the few studies
published in the literature, Fetters et al. investigated motor development in very-low-birth-
weight infants with and without white matter disease67. Thirty preterm participants with white
matter disease, 21 preterm infants without white matter disease and 21 term infants were
recruited. Their analysis of these 72 infants revealed that gross motor development was
significantly impaired among children with white matter disease.
Joint hypermobility has also been examined for its influence on fine and gross motor
development. In 1991, a longitudinal study examined the motor development of 59 infants at 18
months. Tirosh et al. compared fine and gross motor performance of 20 infants with joint
hypermobility and gross motor delays, 19 infants with joint hypermobility and no gross motor
delays and 20 normal controls124. In their follow-up, fine and gross motor development at 5 years
of age was significantly delayed in the group of children exhibiting both joint hypermobility and
gross motor delays at 18 months of age. Moreover, 65% of individuals exhibiting delays at 18
months of age also exhibited delays at 5 years. The prevalence of gross motor delays among
children exhibiting both joint hypermobility and gross motor delays at 18 months of age (65%)
was significantly higher than the other two groups (joint hypermobility and no gross motor
115
delays: 26.3%, normal: 20%). The low sample size of this study, however, warrants further
investigation regarding the persistence of gross motor delays between 18-60 months.
2.2.2.5 Environmental factors
In addition to the previously described factors influencing general motor development,
such as the infant’s sleep position144,145 and parity90,134,138-140,144,145,158, studies have also
investigated the effects of parental psychological distress (PPD) and intimate partner violence
(IPV) on fine and gross motor development68. In a recent cross-sectional study of 16,595
children, Gilbert et al. described that children exposed to both PPD and IPV had 3.0 (95% CI:
1.8-5.0) times the odds of delayed gross motor development of those unexposed68. Simultaneous
exposure to both PPD and IPV, however, did not significantly affect fine motor development.
When Gilbert et al. examined children just exposed to PPD, however, both fine and gross motor
development were significantly delayed compared with those unexposed (fine motor: OR:1.6,
95% CI: 1.3-2.0; gross motor: OR:1.6, 95% CI:1.4-1.8). Furthermore, in a cross-sectional study
by Hanson et al. examining the development of 176 children involved with child welfare,
children having experienced medical neglect and parental substance abuse had lower gross motor
quotients compared with other reasons for welfare involvement.
Lastly, strong evidence is reported for the association between breastfeeding and motor
development. In their prospective cohort study of 540 Greek mother-child dyads, Levantakou et
al. found that longer duration of breastfeeding was associated with higher fine motor scores on
the subscales in the Bayley Scales of Infant Development at 18 months of age (per month of
breastfeeding: =0.29, 95% CI: 0.02-0.56, p=0.034)142. Breastfeeding duration, however, was
not associated with gross motor development. It was also reported that children who breastfed
116
longer than 6 months scored higher on the fine motor subscale compared with those
breastfeeding for less than 6 months. Similar results were also reported by Oddy et al. where
1451 infants who had breastfed for >4 months had significantly higher scores on fine motor and
communication development at 1, 2 and 3 years compared with 869 infants who breastfed for <4
months150.
In sum, strong evidence has been presented for the association between parity90,134,138-
140,144,145,158, psychological distress or violence68 and fine and gross motor development. Further
research is required to understand factors such as community engagement, physical activity, time
spent watching television, and the effects of child care during early child development.
2.3 Discussion
2.2.1 Critical Appraisal of the Current Body of Knowledge
The literature investigating factors associated with general, fine and gross motor
development is extensive. Associations between socio-demographic, maternal health, pregnancy
and birth outcome, child health, and child environmental factors, and child motor development
are supported by numerous methodologically robust studies. Among these cohort studies,
standardized tools were generally employed to assess child neurodevelopment, and the tools
selected had typically been validated for the study population. Moreover, cohort studies were
largely conducted prospectively, reducing the possibility of selection and recall bias. Limitations
within the literature, however, do exist and include the underrepresentation of minorities and
higher-order births, the potential for misclassification of exposure variables and a lack of
Canadian perspectives.
117
As previously described in the exclusion criteria, the scope of this review included
studies conducted in high income countries with 30 or more participants. Given these criteria,
studies were predominantly cohort studies with large sample sizes. These cohort studies,
however, typically underrepresented groups such as minorities or women with higher-order
pregnancies. Few cohort studies had exclusively investigated the motor development of minority
children72,77,95,108,117,138,147,161. This is a limitation of the literature as ethnicity and immigrant
status both influence motor development59,69,138. Moreover, ethnicity has been shown to modify
the effect of various factors on gross and fine motor development117. For example, Wehby et al.
found that folic acid supplementation was associated with increased gross motor development
with a more pronounced effect among African-American children117. Given these differences in
both developmental patterns and ethnicity-specific effects of factors on motor development,
future research must increase the inclusion of minorities in studies examining motor
development.
In addition to minorities, higher-order pregnancies are also underrepresented in the
literature. Concerns regarding the inclusion of high-order pregnancies are due to the increased
likelihood of infants of multiple pregnancies exhibiting congenital anomalies or other childhood
conditions that may be associated with motor development186. Moreover, twins have an increased
risk of preterm delivery, which has also been associated with poor motor development1,52,56,61-
63,65,67,70,71,73-75,78,82,86,89,92,96,106,107. As such, future cohort studies must include children of higher-
order pregnancies to further understand factors influencing motor development of infants from
multiple birth pregnancies.
Despite the underrepresentation of minorities and higher-order pregnancies, other factors
were well distributed. For example, since Touwen’s description of sex differences in motor
118
development assessed by screening tools187, it is common for studies to have equal representation
of both males and females, a characteristic apparent in the presented literature.
The literature in this review also included studies that involved measures of exposure
prone to misclassification bias. For example, studies examining the effect of sleep position on
motor development between the ages of 1-21 months, measured infant sleep position based on
parent reports of the position they laid their child to sleep in67,124,144,145. These studies assumed
that infants’ sleep position did not change throughout the night or as the child aged188. This
assumption may lead to misclassification of the child’s sleep position as most children develop
the capacity to adjust their sleeping position over the age range involved in the studies’
assessments. As such, the position a parent put their child to sleep in may not accurately reflect
the position the child slept most of the night in, thereby leading to misclassification bias.
A similar potential for misclassification is also observed in studies investigating prenatal
exposure to alcohol, tobacco and illicit drug use during pregnancy. In these investigations,
studies typically measured maternal substance use via self-report. To validate self-reports, some
studies assessed urinary128, salivary90 or meconium82,95,154 levels of drug metabolites; however,
this practice was infrequent. Among studies failing to validate self-report of substance use during
pregnancy, misclassification may occur due to maternal recall or reporting bias.
Lastly, few Canadian studies were included in this literature
review49,68,69,89,94,102,119,127,135,143-145. Given the distinct differences between the Canadian and
American health care systems, the at-risk profile for motor development delays may be different
for children of these North American countries. As described above, there is substantial
evidence to suggest that maternal51,57,58,60,68,71,74,77,93,95,103-105,147,150 and child73,78,89,91,107 health
factors influence motor development. It is possible that reduced health care accessibility may
119
exacerbate the influence of health risks on motor development. Moreover, differences in
environmental exposure, availability of community resources or medical practices surrounding
pregnancy and birth outcomes may also influence motor development differently between both
countries. As such, future research is required to simultaneously assess the influence of identified
risk and protective factors for motor development among Canadian children.
120
CHAPTER 3: METHODS
3.1 Study Design
This study is a secondary analysis of data from The All Our Families Study (AOF), a
prospective community-based pregnancy cohort situated in Calgary, Alberta, Canada (n=3388)48.
3.2 The All Our Families Study
The All Our Families (AOF) study was designed to examine the health outcomes of
mothers and their children during and after pregnancy, as well as throughout the child’s
development48. To do so, women were recruited through primary and prenatal care offices and
Calgary Laboratory Services using posters and word of mouth, from May 2008 to December
2010. To be eligible, women must have been at least 18 years of age and less than 25 weeks’
gestation at enrolment, receiving prenatal care in Calgary, and able to complete the study
questionnaires in English. All eligible women were invited to participate in the study. Once
recruited, participants completed questionnaires in the perinatal and early childhood period.
Using unique identifiers, the questionnaire data were linked to electronic medical records for
labour and delivery data. These records enabled validation of self-report data and provided
additional pertinent details surrounding pregnancy complications and birth outcomes.
In total, 3,388 participants were enrolled in the AOF cohort. Of the women in the study,
76% were less than 35 years of age at the time of delivery (mean=31.2 years, S.D.=4.4), 79%
were Caucasian, 78% were born in Canada, 89% had at least some post-secondary education,
94% were married or in a common-law relationship and 69% reported an annual household
income greater than $80,000 (median income in Calgary $88,000)48. When compared with data
collected by the Maternity Experiences Survey (MES), a project implemented by the Public
121
Health Agency of Canada, AOF participants were generally representative of pregnant women
and families in Canada with a few exceptions (Table 4). Compared with the MES, the AOF study
reported a greater proportion of women: 1) attending prenatal or childbirth educational classes,
2) over the age of 35, and 3) with an annual income greater than $40,000. Finally, the proportion
of women reporting having experienced postpartum depression was lower in the AOF study;
however, the proportion of women reporting postpartum health as very good/excellent was also
lower.
Table 4: Comparison of AOF participants to MESa participants (Adapted from
McDonald et al., 201348)
Characteristics AOF % Alberta % Canada %
Demographic Characteristics
> 35 years 24.1 15.6 17.5
Postsecondary completed 76.3 69.5 72.1
>$40K 92.3 77.8 72.6
Primiparousb 48.9 46.0 44.7
Pre-pregnancy BMI (mean) 24.3 24.4 24.4
Pregnancy Characteristicsc
Number of prenatal care visits (mean) 12.8 13.0 12.9
Gestational age at first prenatal care
visit (mean) 9.1 7.2 7.5
Initiated prenatal care in first trimester
(<14 weeks) 93.1 94.9 94.9
First ultrasound <18weeks 85.6 63.4 66.8
Attended prenatal or childbirth
education classes 41.2 33.4 32.7
Satisfied with timing of pregnancy 52.6 50.9 49.5
Feeling happyd upon realization of
pregnancy 87.0 90.8 93.0
Intended to breastfeed 96.2 93.8 90.0
Delivery and postpartum experiences
Preterm birth rate 7.3 6.3 6.2
Caesarean section delivery 24.5 27.3 26.3
122
Short length of maternal stay in hospital
Vaginal delivery (<2 days) 66.8 60.7 33.6
Caesarean section (<4 days) 79.9 59.1 53.0
Initiated breastfeeding 97.8 94.6 90.3
Scoring ≥13 on Edinburgh Postnatal
Depression Scale 5.1 6.5 7.5
Rated postpartum health as very good
or excellent 53.9 73.6 72.5
Postpartum BMI (mean) 25.6 25.5 25.4
a Maternity Experiences Survey 2006-2007; comparisons involve singletons only b according to status at birth c assessed during postpartum in MES (retrospective recall); assessed during pregnancy in
AOF d “happy” derived from collapsing responses of “somewhat happy” and “very happy”
3.3 Data Collection
Participants in the AOF study completed three questionnaires in the perinatal period (22-
24 weeks gestation: Q1; 32-36 weeks gestation: Q2; 4 months postpartum: Q3) and three
questionnaires in the early childhood period (12 months postpartum: Q4; 24 months postpartum:
Q5; 36 months postpartum: Q6; Figure 2)48. Together, the questionnaires captured information
on demographics, pregnancy history, breastfeeding, maternal physical and mental health, child
characteristics and development, parenting, child care, family well-being and lifestyle.
Standardized tools were used to assess child development and milestone attainment, and when
available, tools were used across multiple time-points to identify trajectories of development.
Input from health care providers, epidemiologists and community program leaders aided in
optimizing the questionnaires, while pilot testing questionnaires with pregnant women in the
community ensured clarity and cultural sensitivity.
123
Figure 2: AOF Participant Recruitment Timeline
Questionnaires were mailed to participants along with a paid return envelope48. When
completed, surveys were returned and participants were given library or store gift cards.
Completed questionnaires were digitized using Teleform (Cardiff Teleform, Version 10.1, 2007)
and underwent a verification process to ensure accuracy.
Among those eligible to participate (n=4003), 85% completed at least one of the
questionnaires during the perinatal period (n=3388), while 74% completed all three
questionnaires48. To be eligible for the current study, participants were required to complete the
questionnaire at 24 months postpartum. In total, 1595 participants were included in this
secondary analysis, a response rate of 75.7% (Figure 3).
124
Figure 3: AOF Response Rates163
125
3.4 Outcome Measures
To identify children exhibiting delays in either gross or fine motor development at 24
months of age, data collected using the Ages and Stages Questionnaire, third edition (ASQ-3)
were analyzed. The ASQ-3 is a norm-referenced screening tool used to assess communication,
gross motor, fine motor, problem-solving, and personal-social skills164. With 92% intra-parental
score agreement over a 2-week interval and 93% agreement between parental and trained
examiner scores, the ASQ-3 has high test-retest and inter-observer reliability. Moreover, the
ASQ-3 was also selected as it is widely used throughout Alberta165.
For the purpose of this study, a delay in either fine or gross motor development will be
operationalized as scoring one standard deviation below the normative mean for the respective
subscales. A cut-point of one standard deviation below the normative mean was selected as the
developers of the ASQ-3 have categorized scores below this cut-point as in the “monitoring
zone”164. Investigating risk factors for fine and gross motor development scoring in or below the
“monitoring zone” will contribute to improving the identification of children that are susceptible
to developmental delays, but may remain unscreened or unmonitored.
The AOF cohort includes 114 children only exhibiting fine motor delays, 145 children
only exhibiting gross motor delays and 62 children exhibiting both fine and gross motor delays at
24 months. The rationale for the assessment of fine and gross motor development at 24-months is
two-fold. First, the literature suggests that neurodevelopment screening tools are more reliable
and less situationally sensitive for children older than one year of age164. Second, early
intervention for motor development delays are recommended to occur prior to 18 months of
age166,167. By describing factors associated with delayed motor development prior to 24-months
of age, we can identify at-risk children earlier and intervene more effectively.
126
3.5 Exposure Variables
The literature suggests motor development is influenced by socio-demographic, maternal
health, birth outcomes, child health and child environmental factors. The proposed variables that
underwent descriptive analysis for consideration in later multivariable logistic regression
analysis are described in Tables 5 & 6.
3.5.1 Sociodemographic Factors
To assess influence of SES on fine and gross motor development, this study investigated
the impact of marital status, maternal education, household income, income support from the
government, maternal employment status, housing type, parental age, ethnicity and the child’s
sex on motor developmental outcomes.
3.5.2 Maternal Health Factors
As the effect of maternal BMI is well reported in the literature92,116,161, this study included
maternal BMI (before and during pregnancy) and gestational weight gain as covariates.
Additional maternal physical health covariates include: frequency of exercise (15-30 minutes per
day) during pregnancy, self-report rating of overall physical health, fetal drug exposure, use of
prescription medication, alcohol, cigarettes or illicit drugs.
In an effort to further explore the effects of maternal mental health on fine and gross
motor outcomes, covariates such as feelings about pregnancy, overall emotional health, maternal
separation anxiety, optimism, parenting morale and social support were also explored. Due to the
conflicting results regarding stress on motor development71,137,139, this study also investigated the
influence of scores from the maternal Perceived Stress Scale on the child’s fine and gross motor
127
development. Lastly, measures of maternal anxiety and depression were included to understand
the effect of post-natal maternal mental health on child motor development.
3.5.3 Pregnancy and Birth Outcome Factors
To assess for known risk factors for delayed motor development related to birth
outcomes, this study included term status, type of delivery, pregnancy complications, Apgar
scores, number of babies delivered during pregnancy, and NICU admissions as covariates.
Furthermore, the influence of antenatal steroids on fine and gross motor development will
contribute new information to the literature.
3.5.4 Child Health Factors
This study aims to add to the limited number of studies investigating child health factors
on fine and gross motor development67,76,91,106,108,114,156. To do so, the influence of the child’s
general health and number of visits to health-care professionals were assessed. Moreover, the
influence of children’s communication, gross motor, fine motor, problem solving and personal-
social development at 12 months on fine and motor development at 24 months of age was also
explored.
3.5.5 Environmental Factors
Given the strong evidence supporting an association between parity58,90,92,134,138161 and
motor development this study included the following covariates: number of live births, child
order, number of pregnancies since AOF child born and number of months since last birth and
birth of AOF child. To explore factors related to the family’s health, the partner’s feelings about
128
pregnancy, whether the partner smokes, how smoke is handled in the home, a history of abuse
postpartum and whether food is available in the home were also explored.
Lastly, factors related to the child’s immediate environment were also explored. This
included the investigation of the following covariates: how the child was fed in the first week
postpartum, how the child was generally put to sleep, arrangements for the child’s care, the
child’s television, computer or tablet use habits, the child’s frequency of physical activity and
community resource utilization.
129
Table 5: Candidate variables
Type Variables Time point
Socio-
Demographics
Marital status Q1, Q4
Maternal Education Q1
Born in Canada Q1
Lived in Canada (# years) Q1
Ethnicity Q1
Maternal Age Q1, EHR
Paternal Age Q1
Household Income Q1, Q4
Income support from the government Q1
Maternal employment status Q2, Q3, Q5
Housing type (i.e. house, apartment, duplex/fourplex, ground dwelling,
etc)
Q1, Q3
Do you have a partner Q3, Q4
Child’s sex Q3, EHR
Maternal
Physical Health
Maternal Body Mass Index (pre-pregnancy) Q1
Maternal Body Mass Index (pregnancy) Q1, Q2
Rating of overall physical health Q1-Q4
How often do you exercise 15-30 mins per day during pregnancy? Q1, Q2
Use of prescription medication during pregnancy Q2
Maternal smoking Q2, Q3, Q4
Maternal alcohol consumption Q2, Q3, Q4
Maternal drug use Q2, Q3, Q4
Maternal
Mental Health
Feelings about pregnancy Q1, Q2
Rate emotional health Q1- Q4
Anxiety:
- Spielberger State & Trait Anxiety Scale (high anxiety score =
>40)
- Maternal Separation Anxiety Scale
Q1 - Q4
Q4
Social Support
- Medical Outcomes Study Social Support (low social support =
scored <70)
- National Longitudinal Survey of Children and Youth Social
Support Scale (low social support = scored <17)
Q1, Q2, Q3
Q4
Perceived Stress Scale (a score of 19+ indicated symptoms of stress
being expressed)
Q1 - Q4
Depression:
- Edinburgh Postnatal Depression Scale (high depression score =
>10)
- Postpartum depression
Q1 - Q4
Q4
Optimism: Life Orientation Test – Revised (low optimism score = <15) Q2
Parenting
- Parenting Morale Index (low parenting morale score = <33)
Q3
Pregnancy &
Birth
Outcomes
Term status (i.e. preterm, late preterm, term) or Gestational age Q3, EHR
Type of delivery (i.e. vaginal, C-section) Q3, EHR
Number of days baby spent in the hospital following pregnancy Q3
Antenatal steroids EHR
Pregnancy complications (i.e. poly/oligo, ROM <37 weeks, bleeding) EHR
Apgar scores EHR
NICU admission EHR
Intrauterine growth restrictions EHR
130
a Q1: 22-24 weeks gestation; Q2: 32-36 weeks gestation; Q3: 4 months postpartum; Q4: 12
months postpartum; Q5: 24 months postpartum; EHR: Electronic Health Records
Birth weight/Small-for-gestational age Q3, EHR
Child’s Health Baby’s general health Q4
Healthcare utilization: Number of visits to
- physician/pediatrician
- hospital/urgent care/emergency department
- NICU
- overnight at hospital/hospital re-admit
- specialist/specialty clinic
- chiropractor
- occupational therapist
- physiotherapist
Q3, Q4
Q3, Q4
Q3
Q3, Q4
Q4
Q5
Q5
Q5
Ages and Stages Questionnaire:
- Communication Score
- Problem Solving Score
- Personal-Social Score
- Fine Motor Score
- Gross Motor Score
Q4
Q4
Q4
Q4, Q5
Q4, Q5
Child’s
Environment
Number of live births Q1
Number of months since last birth Q1
Partner happy about pregnancy Q1
Partner smokers Q1
How is smoking handled at home Q1-Q4
Breastfeeding Q3, Q4
How was the baby fed during the first week Q3
Sleep position Q3
Community resource utilization:
- Library
- Parenting classes
- Calgary Learning Center
- Family Literacy programs
- Local immigrant serving group
- Story time in the community
- Informal moms and tots group
- Parenting group on the Internet
- Television show about parenting
- Daycare facility
- Families Matter
- Calgary Child
- A local spiritual institution or organization
- A local fitness center
- Parent Link center
- Local community health center
Q3, Q4, Q5
Abuse postpartum Q3
Occasion where food didn’t last and money was unavailable to buy more Q3
Child care arrangement Q3, Q4, Q5
Child order Q5
Do you have a computer/tablet and your child uses it Q5
Time spent watching TV Q5
Time spent doing physical activity Q5
131
Table 6: Categorization of candidate variables
Type Variables Categorization
Outcome Fine Motor Development – ASQ-3 at 24 months
postpartum
0 = On Schedule (>43.43)
1 = Monitor (<43.43)
Gross Motor Development – ASQ-3 at 24 months
postpartum
0 = On Schedule (>46.40)
1 = Monitor (<46.40)
Socio-
Demographics
Marital status 0 = Single/Divorced
1 = Married/Common-law
Maternal Education 0 = High School or less
1 = Some or completed post-
secondary
Born in Canada 0 = Born in Canada
1 = Not born in Canada
Lived in Canada (# years) 0 = >5 years
1 = <5 years
Ethnicity 0 = White
1 = Other
Maternal Age 0 = <35 years of age
1 = >35 years of age
Paternal Age 0 = <35 years of age
1 = >35 years of age
Household Income 0 = <$80,000
1 = >$80,000
Income support from the government 0 = No
1 = Yes
Maternal employment status 0 = Not working
1 = Working
Housing type (i.e. house, apartment, duplex/fourplex,
ground dwelling, etc)
0 = House, townhouse
1 = Apartment, condo,
duplex/fourplex, other
Do you have a partner 0 = Yes
1 = No
Child’s sex 0 = Female
1 = Male
Maternal
Physical
Health
Maternal Body Mass Index (pre-pregnancy) 0 = Underweight/Normal weight
1 = Overweight/Obese
Maternal Body Mass Index (pregnancy) 0 = Underweight/Normal weight
1 = Overweight/Obese
Rating of overall physical health 0 = Excellent, very good, good
1 = Fair, poor
How often do you exercise 15-30 mins per day during
pregnancy?
0 = >3 times
1= <3 times
Use of prescription medication during pregnancy 0 = No
1 = Yes
Maternal smoking 0 = No
1= Yes
Maternal alcohol consumption 0 = No
1 = Yes
Maternal drug use 0 = No
1 = Yes
Maternal Feelings about pregnancy 0 = Happy
1 = Unhappy
132
Mental
Health
Rate emotional health 0 = Excellent, very good, good
1 = Fair, poor
Anxiety:
- Spielberger State & Trait Anxiety Scale (high
anxiety score = >40)
- Maternal Separation Anxiety Scale
0 = <40
1 = >40
0 = < 1SD
1 = >1SD
Social Support
- Medical Outcomes Study Social Support (low
social support = scored <70)
- National Longitudinal Survey of Children and
Youth Social Support Scale (low social support =
scored <17)
0 = <70
1 = >70
0 = >17
1 = <17
Perceived Stress Scale (a score of >19 indicated
symptoms of stress being expressed)
0 = <19
1 = >19
Depression:
- Edinburgh Postnatal Depression Scale (high
depression score = >10)
- Postpartum depression
0 = <10
1 = >10
0 = No
1 = Yes
Optimism: Life Orientation Test – Revised (low
optimism score = <15)
0 = >15
1 = <15
Parenting
- Parenting Morale Index (low parenting morale
score = <33)
0 = >33
1 = <33
Pregnancy &
Birth
Outcomes
Term status (i.e. preterm, late preterm, term) or
Gestational age
0 = >37 weeks
1 = < 37 weeks
Type of delivery (i.e. vaginal, c-section) 0 = Vaginal
1 = Caesarean Section
Number of days baby spent in the hospital following
pregnancy
0 = <3 days
1 = >3 days
Antenatal steroids 0 = No
1 = Yes
Pregnancy complications (i.e. poly/oligo, ROM <37
weeks, bleeding)
0 = No
1 = 1 or more
Apgar scores 0 = >7
1 = <7
NICU admission 0 = No
1 = Yes
Intrauterine growth restrictions 0 = No
1 = Yes
Weight-for-length Percentiles at 12 months (WHO
Growth Chart)
0 = >10th percentile, sex-specific
1 = <10th percentile, sex-specific
Birth weight 0 = <2500g
1 = >2500g
Child’s
Health
Baby’s general health 0 = Excellent, very good, good
1 = Fair, poor
Healthcare utilization: Number of visits to
- physician/pediatrician
- hospital/urgent care/emergency department
- NICU
- overnight at hospital/hospital re-admit
0 = None
1 = 1 or more
133
- specialist/specialty clinic
- chiropractor
- occupational therapist
- physiotherapist
Ages and Stages Questionnaire:
- Communication Score
- Problem Solving Score
- Personal-Social Score
- Fine Motor Score
- Gross Motor Score
0 = >15.64
1 = <15.64
0 = >27.32
1 = <27.32
0 = >21.73
1 = <21.73
0 = >43.43
1 = <43.43
0 = >46.40
1 = <46.40
Child’s
Environment
Number of live births 0 = None
1 = 1 or more
Number of months since last birth 0 = > 24 months
1 = <24 months
Partner happy about pregnancy 0 = Happy
1 = Unhappy
Partner smokers 0 = No
1 = Yes
How is smoking handled at home 0 = No smoking inside the house
1 = Smoking in the house
Breastfeeding 0 = Yes
1 = No
How was the baby fed during the first week 0 = Only breastfeeding
1 = Most/some breastfeeding
Community resource utilization:
- Library
- Parenting classes
- Calgary Learning Center
- Family Literacy programs
- Local immigrant serving group
- Story time in the community
- Informal moms and tots group
- Parenting group on the Internet
- Television show about parenting
- Daycare facility
- Families Matter
- Calgary Child
- A local spiritual institution or organization
- A local fitness center
- Parenting resource book
- Parent Link center
- Local community health center
0 = >1 or more
1 = None
Abuse postpartum 0 = No
1 = Yes
Occasion where food didn’t last and money was
unavailable to buy more
0 = No
1 = Yes
Child care arrangement 0 = Parent/co-parent/etc.
1 = Day care
Child order 0 = First Child
1 = Other
134
Do you have a computer/tablet and your child uses it 0 = No
1 = Yes
Time spent watching TV on a typical day 0 = <1 hour
1 = >1 hour
Time spent doing physical activity 0 = <1 hour
1 = >1 hour
135
3.6 Statistical Methods
3.6.1 Descriptive Statistics
To describe the characteristics of the sample used in this analysis, frequencies and
percentages were computed for categorical variables.
3.6.2 Bivariate Analysis
Pearson’s chi-square test was used to assess the relationship between study variables and
fine or gross motor development at 24-months of age. If expected cell counts were less than five,
Fisher’s exact test was employed to calculate the exact p-value for the relationship between two
variables. The use of Fisher’s exact test is appropriate among small sample sizes as it does not
rely on the statistical approximations used in chi-square tests that require large sample sizes.
3.6.3 Multivariable Logistic Regression
Classification trees by recursive partitioning were created to identify candidate risk or
protective factors for both fine and gross motor delays. Using R for Mac OS X168, trees were
created using the default settings of the rpart package169. To attempt to improve the fit of tree, the
number of observations in a node for a split to be attempted was lowered to a minimum of 10.
Using recursive partitioning, important variables could not be identified. As such
candidate variables were identified using bivariate analysis, where statistically significant
(p<0.10) variables were considered eligible for inclusion in the regression models. Of the eligible
variables, priority was given to variables with: 1) evidence supporting an association between the
variable and either fine or gross motor development in the literature, 2) variables with the highest
risk ratios and 3) variables with response rates >80%.
136
With 177 and 207 children identified as experiencing fine or gross motor delays,
respectively, there was a sufficient sample size to include 17 variables in a regression model
investigating fine motor delays, and 20 variables in a regression model investigating gross motor
delays170,171. As such, two separate multivariable logistic regression models included up to 17
and 20 of the most relevant variables to examine the effect of the covariates on fine or gross
motor development at 24 months of age, respectively.
In each model, the most relevant variables were simultaneously inserted into the model.
To create a parsimonious model, nonsignificant (p>0.05) variables were omitted one at a time,
where at each iteration the variable with the largest non-significant p-value was removed. If
multiple nonsignificant variables had approximately the same p-value, the variable that was not
measured using a validated scale was removed first. If, however, nonsignificant variables were
identified as confounders, whereby removal of the variable changed any of the estimates by
greater than 10%, the variable remained in the model. All significant or confounding variables
were carried forward and included in the final model. Prior to finalizing the model, any variable
not originally selected for the multivariable model was added one at a time into the model172. If
the variable was neither significant nor a confounder it was removed172,173.
Missing data was addressed using listwise deletion. Through listwise deletion, cases were
dropped from the analysis if data was missing for any of the variables included in the model.
Though listwise deletion decreases the statistical power and does not include all the available
information, it was employed in this analysis as it is assumed that data was missing at random.
As such, if the missingness of the data was random and not related to the outcome, litswise
deletion may produce unbiased estimates.
137
Finally, a Hosmer and Lemeshow test was performed on the final model to assess
goodness-of-fit173. As is standard practice, the Hosmer-Lemeshow test was performed using 10
groups. As part of the Hosmer-Lemeshow test, a chi-square analysis was performed to compare
the observed responses and the expected number of responses according to our model. A large p-
value suggests that there was no significant difference between the observed and expected
responses, suggesting the models was not poorly fitted.
Effect estimates from the final logistic regression model are presented as odd ratios (OR)
with 95% Confidence Intervals (CI). An alpha level of 5% was used for statistical tests.
Statistical analyses were performed using Stata/SE for Mac version 14.1174.
3.7 Ethics
The All Our Families Study was approved by the Child Health Research Office, Alberta
Children’s Hospital, Alberta Health Services, and the Conjoint Health Research Ethics Board of
the Faculties of Medicine, University of Calgary. Written informed consent was obtained from
the study participants at the time of recruitment, who were also provided copies for their records.
138
CHAPTER FOUR: FACTORS RELATED TO DELAYED FINE AND GROSS MOTOR
DEVELOPMENT AMONG ALBERTAN CHILDREN AT 24 MONTHS OF AGE
4.1 Background
Up to 15% of children1,2 between 3-17 years of age experience either poor physical,
intellectual or social development, making developmental delays the most common childhood
disability2. Long-term repercussions of developmental delays, however, can be mitigated among
some children if intervention strategies are initiated early in childhood38. To support early
identification of children experiencing delays, population-wide developmental screening in
Canada has been proposed46. Recently, the Canadian Task Force on Preventive Health Care
assessed the effectiveness of population-based screening in primary care settings for children
aged 1-4 years46. The results of their systematic review informed their recommendation against
broadly screening child development using standardized tools in children aged 1-4 years with no
apparent signs of delay, and whose parents or clinicians have no concerns about development.
This recommendation, however, does not apply to children who present with signs or symptoms
that could indicate developmental problems, or whose development is being closely monitored
because of identified risk factors. Consequently, to ensure children that present with possible
sign of development delays are identified early and appropriately monitored, contemporary at-
risk profiles for developmental delays must be developed175,176.
Among the earliest recognizable risk indicators of global developmental complications is
delayed motor development5. The development of motor skills enables infants to interact with
their environment, shaping later cognitive and linguistic development7,8. The development of
motor skills has been shown to be influenced by sociodemographic, biological, psychosocial and
environmental factors.
139
Children born preterm, with low birth weight or who required neonatal care, have long
been recognized as at risk for motor delays51,52,56,61-63,65,67,70-75,78,82,86,89,92,96,106,107,141. In Canada,
these children are also more likely to receive consistent screening, leading to earlier referrals to
developmental intervention programs175,176. Recently, however, the influence of socioeconomic
factors on motor development has garnered increased attention. Children growing up in families
of low socioeconomic status are at an increased risk of poor fine and gross motor
development81,90,106,107,154,175,176. It has been suggested that children of low-income families may
have less stimulating environments, such as less space inside the home to safely explore,
increasing the risk for developmental delay177,178. Evidence also suggests that environmental
factors increasing a child’s psychosocial stress, such as poor maternal mental
health51,57,58,60,71,137,139 and intimate partner violence68, are also associated with poor motor
development.
Though a variety of biological, sociodemographic and environmental risk factors have
been shown to be independently associated with fine and gross motor development, few studies
have examined the cumulative effects of risk factors110. Moreover, no Canadian studies have
simultaneously assessed the influence of sociodemographic, biological and environmental factors
on motor development. Given the differences in healthcare and community resource
accessibility, sociodemographic profiles, and cultural expectations of motor skills across
nations47, this study aimed to evaluate factors influencing fine and gross motor development of
Albertan children at 24 months of age. Using detailed information collected during perinatal and
early childhood period by the All Our Families (AOF) study, the influence of sociodemographic,
maternal health, birth outcome, child health and child environmental factors on motor
development was assessed48.
140
4.2 Methods
4.2.1 The All Our Families Study
The All Our Families Study (AOF) is a prospective community-based pregnancy cohort,
situated in Calgary, Alberta, Canada (n=3388)48. A detailed overview of the study design,
recruitment, eligibility and data collection is described elsewhere48,179. In brief, women were
recruited through community-based low-risk pregnancy clinics, Calgary Laboratory Services (the
single provider of public health laboratory services), and by word of mouth from May 2008 to
December 2010. To be eligible, women must have been at least 18 years of age, sufficiently
literate in English to complete questionnaires independently and were less than 25-weeks
gestation. Women planning on moving away from Calgary during their pregnancy were
excluded.
The AOF cohort represents the pregnant and parenting population in Calgary48. When
compared with data collected by the Maternity Experiences Survey (MES), a project
implemented by the Public Health Agency of Canada, AOF participants were generally
representative of pregnant women and families in Canada with a few exceptions: the AOF study
reported a greater proportion of women: 1) attending prenatal or childbirth educational classes;
2) over the age of 35; 3) with an annual income greater than $40,000; 4) not experiencing
postpartum depression; and 5) reporting their postpartum health as fair or poor.
Once enrolled into the study, participants were requested to complete three questionnaires
in the perinatal period (22-24 and 32-36 weeks gestation, and 4 months postpartum) and two
questionnaires in the early childhood period (12 and 24 months postpartum)48. Input from health
care providers, epidemiologists and community program leaders aided in optimizing the
questionnaires, while pilot testing questionnaires with pregnant women in the community
141
ensured clarity and cultural sensitivity. Questionnaires collected detailed information on
demographics, lifestyle, mental, psychosocial and physical health, pregnancy history, health
service utilization, quality of life, and breastfeeding. Using unique identifiers, the questionnaire
data was linked to electronic medical records for labour and delivery. These records enabled
validation of maternal report of gestational age, birth weight, child’s sex, multiple gestation
pregnancy, type of delivery, epidural use and labour induction. Electronic health records also
provided additional pertinent details surrounding pregnancy complications and birth outcomes
such as pregnancy complications, antenatal steroid use, Apgar scores, child admission to the
neonatal intensive care unit following birth and intrauterine growth restrictions.
This study is a secondary analysis of data from the AOF study. To be eligible for the
current analysis, participants were required to complete the questionnaire at 24 months
postpartum. Of 2106 participants who were eligible for follow up at 24 months, 1595 completed
the questionnaire for a response rate of 75.7%163.
The All Our Families Study was approved by the Child Health Research Office, Alberta
Children’s Hospital, Alberta Health Services, and the Conjoint Health Research Ethics Board of
the Faculties of Medicine, University of Calgary. Written informed consent was obtained from
the study participants at the time of recruitment, who were also provided copies for their records.
4.2.3 Assessment of Fine and Gross Motor Development
To assess infants’ fine and gross motor development at 24 months of age, mothers were
asked to complete the Ages and Stages Questionnaire-Third Edition (ASQ-3), a validated scale
for measuring child development between 1-66 months of age180. The ASQ-3 is a norm-
referenced screening tool, commonly used in Calgary, Alberta165 to assess five developmental
142
domains: 1) communication, 2) gross motor, 3) fine motor, 4) problem solving, 5) personal-
social164. To complete the questionnaire, parents were asked to indicate if their child could
complete 30 age-appropriate activities. Using parental evaluations of their child’s performance
on each activity, development across each domain was categorized as typical development,
development requiring monitoring (scoring one standard deviation below the normative mean),
or development requiring further professional assessment (scoring two standard deviations below
the normative mean). In this study, fine or gross motor delays were operationalized as scoring
one standard deviation below the normative mean for the respective subscale.
The ASQ-3 has demonstrated high test-retest reliability with 92% agreement between
scores parental scores separated by two-weeks, with intraclass correlation ranging from 0.75-
0.82164. Moreover, the ASQ-3 has also demonstrated high inter-observer reliability with 93%
agreement between parent and trained examiner scores, with intraclass correlations ranging from
0.43-0.69 by area.
4.2.4 Exposure Variables
In the current analysis, sociodemographic, maternal health, birth outcomes, child health
and child environmental factors were considered. Exposure factors were selected based on
theoretical plausibility or empirical evidence from the literature. Assessment point and
categorization of each variable are included in Table 5 and 6.
Sociodemographic factors: During pregnancy, information was collected on marital
status (married/common-law [reference group], single), maternal education (some or completed
post-secondary [reference group], high school or less), maternal employment status (working
[reference group], not working), duration mother has lived in Canada (more than 5 years
143
[reference group], 5 years or less), maternal age (35 years or more [reference group], less than 35
years), paternal age (35 years or more [reference group], less than 35 years), household income
($80,000 or more [reference group], less than $80,000), income support from the government (no
[reference group], yes) and housing type (house/townhouse [reference group],
apartment/condo/duplex/fourplex/other). Postpartum questionnaires updated information on
marital status, household income, employment status and housing type and collected information
on the child’s sex (female [reference group], male).
Maternal health factors: Information was collected on both maternal physical and mental
health. Maternal physical health factors included maternal perception of overall physical health
(excellent/very good/good [reference group], fair/poor), pre-pregnancy body mass index (BMI;
normal weight [reference group], underweight, overweight, obese), BMI during second and third
trimester, weight gain during pregnancy (adequate [reference group], inadequate, excessive),
exercise during pregnancy (three or more times per day [reference group], less than three times
per day), use of prescription medication (no [reference group], yes), and maternal consumption
of tobacco (no [reference group], yes), alcohol or illicit drugs (no [reference group], yes). Mental
health factors included maternal perception of overall emotional health (Excellent/very
good/good [reference group], fair/poor), feelings about pregnancy (happy [reference group],
unhappy), Spielberger State & Trait Anxiety Scale (low symptoms of anxiety [reference group];
high symptoms of anxiety), Medical Outcomes Study Social Support (high social support
[reference group], low social support), National Longitudinal Survey of Children and Youth
Social Support Scale (high social support [reference group], low social support), perceived stress
scale (low perceived stress [reference group], high perceived stress), Edinburgh Postnatal
Depression Scale (low symptoms of depression [reference group], high symptoms of
144
depression), Life Orientation Test – Revised (high optimism [reference group], low optimism),
Parenting Morale Index (high parenting morale [reference group], low parenting morale), history
of mental health conditions (no [reference group], yes) and Maternal Separation Anxiety Scale
(no [reference group], yes).
Pregnancy and birth outcome factors: Together, questionnaires and electronic health
records collected information on numbers of babies delivered during their study pregnancy
(singleton [reference group], higher order pregnancy), the number of days their child spent in the
hospital following delivery (< 3 days [reference group], >3 days), term status of their baby (>37
weeks gestation [reference group], <37 weeks gestation), and their baby’s birth weight (>2500g
[reference group], <2500g). Term status and birth weight were verified using electronic health
records. Electronic health records also provided information on antenatal steroid use (no
[reference group], yes), infection during pregnancy (no [reference group], yes), pregnancy
complications (no [reference group], yes), Apgar scores (no [reference group], yes), neonatal
intensive care unit admission (NICU: no [reference group], yes) and intrauterine growth
restrictions (no [reference group], yes).
Child health factors: Beginning at 4-months postpartum, questionnaires collected
information regarding maternal perception of baby’s general health (excellent/very good/good
[reference group], fair/poor) and number of visits to either a physician/pediatrician (none
[reference group], >1), hospital/urgent care/emergency department (none [reference group], >1),
neonatal intensive care unit (none [reference group], >1), specialist/specialist clinic (none
[reference group], >1), chiropractor (none [reference group], >1), occupational therapist (none
[reference group], >1) or physiotherapist (none [reference group], >1). The number of overnight
stays or re-admissions into a hospital were also recorded (no [reference group], yes). Mothers
145
were also asked to complete the ASQ-3 at 12 months postpartum. Developmental delays were
operationalized as scoring one standard deviation below the normative mean for the respective
subscale.
Child environment factors: Questionnaires collected information on child birth order
(first/only child [reference group], middle or youngest child), number of months since last birth
(>24 months [reference group], <24 months), partners feelings about pregnancy (happy
[reference group], unhappy), partner smoking status (non-smoker [reference group], smoker),
how smoke is handled in the home (No smoking inside the house [reference group], smoking in
the house), breastfeeding practices (yes [reference group], no), how the baby was fed during their
first week of life (only breastfed [reference group], most/some breastfeeding), child’s sleep
position (supine[reference group], prone/on side), community resource utilization (library,
parenting classes, Calgary Learning Center, family literacy programs, local immigrant serving
group, story time in the community, informal moms and tots group, parenting group on the
Internet, television show about parenting, Daycare facility, Families Matter, Calgary’s Child,
local spiritual institution or organization, local fitness center, parenting resource book, parent
Link center, local community health center; no [reference group], yes), maternal abuse
postpartum (no [reference group], yes), food security status (secure [reference group], insecure),
child care arrangement (parent/co-parent/relative [reference group], day care), child
computer/tablet use (<1 hour [reference group], >1 hour), time spent watching television (<1
hour [reference group], >1 hour) and time spend doing physical activity (<1 hour [reference
group], >1 hour).
146
4.2.5 Data Analysis
To describe the characteristics of the sample used in this analysis, frequencies and
percentages were computed. Pearson’s chi-square test was used to assess the relationship
between study variables and fine or gross motor development at 24-months of age. If cell counts
were less than five, Fisher’s exact test was employed.
Two separate multivariable logistic regression models were created to examine the effect
of the covariates on fine or gross motor development at 24 months of age, respectively.
Candidate variables were identified using bivariate analysis, where statistically significant
(p<0.10) variables were considered eligible for inclusion in the regression models. Of the eligible
variables, priority was given to variables with: 1) evidence supporting an association between the
variable and motor development in the literature, 2) variables with the highest risk ratios and 3)
variables with response rates >80%. To create a parsimonious model, nonsignificant (p>0.05)
variables were omitted one at a time, where at each iteration the variable with the largest non-
significant p-value was removed. If, however, nonsignificant variables were identified as
confounders, whereby removal of the variable changed any of the estimates by greater than 10%,
the variable remained in the model. All significant or confounding variables were carried
forward and included in the final model. Prior to finalizing the model, any variable not originally
selected for the multivariable model was added one at a time into the model172. If the variable
was neither significant nor a confounder it is removed. Finally, a Hosmer-Lemeshow test using
10 groups was performed on the final model to assess goodness-of-fit173.
Effect estimates from the final logistic regression model were presented as odd ratios
(OR) with 95% Confidence Intervals (CI). An alpha level of 5% was used for statistical tests.
Bivariate and regression modelling was performed using Stata/SE for Mac version 14.1174.
147
4.3 Results
4.3.1 Participant Characteristics
Table 8 provides a summary of the descriptive statistics for significant variables and fine
or gross motor development at 24-months of age. A complete summary of the descriptive
statistics for each of the study variables is found in Appendix A. Of the participants included in
this analysis 97.9% of mothers were married or in a common-law relationship, 91.7% had some
form of post-secondary education, 91.5% had lived in Canada for more than five years and
72.6% had a household income of $80,000 or more (Table 7). Mothers generally reported high
levels of good overall physical (90.8%) and emotional (92.7%) health. The proportion of women
reporting depression or anxiety during pregnancy was 15.4% and 18.1%, respectively. Similar
proportions of depression (11.1%) and anxiety (13.6%) were also reported at 4 months
postpartum.
Most of the children included in this analysis had a gestational age greater than 37 weeks
(85.5%) with uncomplicated pregnancies (93.6%). Infants were typically delivered vaginally
(75.5%) and most did not require antenatal steroids (96.9%) or neonatal intensive care unit
admission (91.4%). There was approximately an equal proportion of primiparous (48.0%) and
multiparous pregnancies and of male (51.9%) and female (48.1%) children. In total, there were
177 and 207 children identified as experiencing fine or gross motor delays at 24 months of age,
respectively.
148
Table 7: Participant characteristics
Socio-demographic Characteristics n (%) Marital statusa
Single/Divorced/Separated/Widowed
Married/Common-law
28 (2.1)
1,289 (97.9)
Maternal Educationa
High School
Some or completed post-secondary
132 (8.3)
1,452 (91.7)
Time in Canadaa
Born in Canada/Lived in Canada for 5+ years Lived in Canada less than 5 years
1,445 (91.5)
135 (8.5)
Ethnicitya
White/Caucasian Other
1,301 (82.1)
283 (17.9)
Maternal Agea
Less than 35 years of age
35 years of age or older
1,232 (79.3)
321 (20.7)
Household Incomea
<$80,000
>$80,000
418 (27.4)
1,107 (72.6)
Maternal employment statusb
Working
Not working
971 (62.0)
595 (38.0)
Child’s Sexc
Boy Girl
805 (51.9)
745 (48.1)
Maternal Health Characteristics n (%) Rating of overall physical healtha
Good (Excellent, Very Good, Good) Not good (Fair, Poor)
1,438 (90.8)
146 (9.2)
Use of prescription medication during pregnancyb
No Yes
902 (57.6)
665 (42.4)
Maternal smoking during pregnancyb
No
Yes
1,403 (89.4)
166 (10.6)
Maternal alcohol consumption during pregnancyb
No
Yes
811 (51.7)
758 (48.3)
Maternal drug use during pregnancyb
No
Yes
1,507 (96.1)
61 (3.9)
Rate emotional healtha
Good (Excellent, Very Good, Good) Not good (Fair, Poor)
1,469 (92.7)
115 (7.3)
Maternal anxiety during pregnancyb
No (<40) Yes (>40)
1,256 (81.9)
278 (18.1)
149
Maternal anxiety post-partumc
No (<40)
Yes (>40)
1,278 (86.4)
202 (13.6)
Social support during pregnancyb
Adequate support (70+)
Inadequate support (<70)
1,391 (88.4)
183 (11.6)
Social support post-partumc
Adequate support (70+) Inadequate support (<70)
1,311 (86.1)
211 (13.9)
Perceived Stress post-partumc
Low symptoms of stress Symptoms of stress
1,308 (86.0)
213 (14.0)
Depression during pregnancyb
No (<10)
Yes (>10)
1,339 (84.6)
244 (15.4)
Depression post-partumc
No (<10)
Yes (>10)
1,374 (88.9)
172 (11.1)
Pregnancy and Birth Outcome Characteristics n (%) Term status
>30 weeks’ gestation
< 30 weeks’ gestation
1,533 (99.6)
7 (0.4)
Type of deliveryc
Vaginal
Caesarean section
1,174 (75.7)
377 (24.3)
Antenatal steroidsd
No Yes
1,314 (96.9)
42 (3.1)
Pregnancy complications (i.e. poly/oligo, ROM <37 weeks,
bleeding)d
No
Yes
1,494 (93.6)
103 (6.4)
Apgar scoresd
>7
<7
1,395 (98.6)
20 (1.4)
NICU admissiond
No Yes
1,459 (91.4)
137 (8.6)
Intrauterine growth restrictionsd
No
Yes
1,560 (97.7)
36 (2.3)
Child Health Characteristics n (%) Maternal perception of baby’s general healthe
Good (Excellent, Very Good, Good) Not good (Fair, Poor)
1,309 (99.4)
8 (0.6)
Child has visited the hospital in first 2 years of life?
No
Yes
773 (57.8)
565 (42.2)
150
Child has visited an occupational therapist in first 2 years of
life?
No
Yes
1,579 (98.9)
17 (1.1)
Child has visited a physiotherapist in first 2 years of life?
No Yes
1,562 (97.9)
34 (2.1)
Ages and Stages Questionnairee
- Communication Score Typical Development
Delayed Development
- Problem Solving Score Typical Development Delayed Development
- Personal-Social Score Typical Development Delayed Development
- Fine Motor Score Typical Development
Delayed Development
- Gross Motor Score Typical Development
Delayed Development
1,042 (94.6)
59 (5.4)
912 (83.1)
186 (16.9)
960 (87.4)
139 (12.6)
999 (90.8)
101 (9.2)
854 (77.6)
246 (22.4)
Child Environment Characteristics n (%) How is smoking handled at homee
No smoking inside the house
Smoking permitted in the house
1,249 (96.7)
43 (3.3)
Was breastfeeding initiated, even for a short period?
No
Yes
33 (2.1)
1,519 (97.9)
Community Resource Utilization
<1 >1
307 (19.2)
1,289 (80.8)
Birth order of the AOB child
Oldest/only child Youngest/Middle
765 (48.0)
830 (52.0)
151
Table 8: Descriptive statistics for the potential sociodemographic, maternal health, birth outcome, child health, and
environmental factors
Gross Motor Delays at 24 months
(Missing n=36) __________________________________________________
Typical
Development
n (row/column%)
Delayed
Development
n (row/column%)
Missing p-value
Fine Motor Delays at 24 months
(Missing n=45) ________________________________________________
Typical
Development
n (row/column%)
Delayed
Development
n (row/column%)
Missing p-value
Sociodemographics Factors
Were you born in Canada?
Yes
No
1092 (87.29/81.25)
252 (84.00/18.75)
159 (12.71/76.81)
48 (16.00/23.19)
11
0.132
1116 (89.93/81.64)
251 (83.39/18.36)
125 (10.07/71.43)
50 (16.61/28.57)
11
0.001
How many years have you lived in
Canada?
>60 months
<60 months
1229 (86.92/91.65)
112 (84.85/8.35)
185 (13.08/90.24)
20 (15.15/9.76)
16
0.086
1253 (89.18/92.00)
109 (82.58/8.00)
152 (10.82/86.86)
23 (17.42/13.14)
16
0.022
How would you describe your ethnic
background?
Other
White/Caucasian
231 (84.62/17.19)
1113 (87.16/82.81)
42 (15.38/20.39)
164 (12.84/79.61)
12
0.261
221 (80.66/16.17)
1146 (90.45/83.83)
53 (19.34/30.46)
121 (9.55/69.54)
12
<0.001
Household income at Q1?
<$80,000
>$80,000
351 (85.40/27.21)
939 (86.78/72.79)
60 (14.60/29.56)
143 (13.22/70.44)
71
0.486
349 (85.54/26.64)
961 (89.31/73.36)
59 (14.46/33.91)
115 (10.69/66.09)
71
0.044
Maternal employment at Q2?
Working
Not Working
836 (87.91/62.90)
493 (84.85/37.10)
115 (12.09/56.65)
88 (15.15/43.35)
30
0.087
845 (89.14/62.41)
509 (88.52/37.59)
103 (10.86/60.95)
66 (11.48/39.05)
30
0.712
Child’s sex (biological) (Q3)
Boy
Girl
690 (87.67/52.55)
623 (85.58/47.45)
97 (12.33/48.02)
105 (14.42/51.98)
46
0.230
684 (87.36/51.20)
652 (90.06/48.80)
99 (12.64/57.89)
72 (9.94/42.11)
46
0.099
152
Maternal Physical Health
Rating of overall physical health at
22-24 weeks gestation?
Excellent/Very Good/Good
Fair/Poor
1224 (86.93/91.14)
119 (83.80/8.86)
184 (13.07/88.89)
23 (16.20/11.11)
12
0.296
1249 (89.09/91.43)
117 (84.17/8.57)
153 (10.91/87.43)
22 (15.83/12.57)
12
0.082
Rating of overall physical health at 4
months postpartum?
Excellent/Very Good/Good
Fair/Poor
1161 (86.45/88.36)
153 (87.93/11.64)
182 (13.55/89.66)
21 (12.07/10.34)
45
0.589
1191 (89.15/89.08)
146 (84.39/10.92)
145 (10.85/84.30)
27 (15.61/15.70)
45
0.064
Since becoming pregnant, did you
drink any alcohol?
Yes
No
642 (86.87/48.23)
689 (86.56/51.77)
97 (13.13/47.55)
107 (13.44/52.45)
27
0.855
664 (90.59/48.93)
693 (87.28/51.07)
69 (9.41/40.59)
101 (12.72/59.41)
27
0.040
Since your baby was 4 months old,
have you consumed any alcoholic
drink?
Yes
No
834 (87.51/74.60)
284 (84.78/25.40)
119 (12.49/70.00)
51 (15.22/30.00)
279
0.203
863 (90.84/75.24)
284 (84.78/24.76)
87 (9.16/63.04)
51 (15.22/36.96)
279
0.002
Since your baby was 4 months old,
have you used street drugs?
Yes
No
19 (70.37/1.70)
1099 (87.22/98.30)
8 (29.63/4.73)
161 (12.78/95.27)
280
0.010
22 (81.48/1.92)
1124 (89.49/98.08)
5 (18.52/3.65)
132 (10.51/96.35)
280
0.182
Maternal Mental Health
Rate emotional health at 22-24
weeks gestation
Excellent/Very good/Good
Fair/Poor
1253 (87.20/93.23)
91 (80.53/6.77)
184 (12.80/89.32)
22 (19.47/10.68)
12
0.044
1272 (88.95/93.12)
94 (84.68/6.88)
158 (11.05/90.29)
17 (15.32/9.71)
12
0.172
Rate emotional health at 32-36
weeks gestation
Excellent/Very good/Good
Fair/Poor
1258 (87.12/94.59)
72 (80.00/5.41)
186 (12.88/91.18)
18 (20.00/8.82)
28
0.054
1276 (88.92/94.17)
79 (87.78/5.83)
159 (11.08/93.53)
11 (12.22/6.47)
28
0.738
153
Rate emotional health at 4 months
postpartum
Excellent/Very good/Good
Fair/Poor
1226 (86.77/93.30)
88 (84.62/6.70)
187 (13.23/92.12)
16 (15.38/7.88)
44
0.534
1254 (89.19/93.79)
83 (80.58/6.21)
152 (10.81/88.37)
20 (19.42/11.63)
44
0.008
Anxiety at 32-36 weeks gestation
No (<40)
Yes(>40)
1064 (86.50/81.72)
238 (87.18/18.28)
166 (13.50/82.59)
35 (12.82/17.41)
6
0.767
1098 (89.56/82.74)
229 (85.13/17.26)
128 (10.44/76.19)
40 (14.87/23.81)
62
0.037
Anxiety at 12 months postpartum
No (<40)
Yes(>40)
910 (87.16/83.79)
176 (86.27/16.21)
134 (12.84/82.72)
28 (13.73/17.28)
323
0.729
940 (90.21/84.53)
172 (85.15/15.47)
102 (9.79/77.27)
30 (14.85/22.73)
323
0.032
Social Support at 22-24 weeks
gestation
Adequate (<70)
Inadequate (>70)
1188 (87.29/88.92)
148 (82.22/11.08)
173 (12.71/84.39)
32 (17.78/15.61)
22
0.060
1216 (89.81/89.54)
142 (79.78/10.46)
138 (10.19/79.31)
36 (20.22/20.69)
22
<0.001
Social Support at 32-36 weeks
gestation
Adequate (<70)
Inadequate (>70)
1149 (87.51/86.98)
172 (81.52/13.02)
164 (12.49/80.79)
39 (18.48/19.21)
38
0.017
1172 (89.67/87.07)
174 (83.65/12.93)
135 (10.33/79.88)
34 (16.35/20.12)
38
0.010
Social Support at 4 months
postpartum
Adequate (<70)
Inadequate (>70)
1120 (87.30/87.02)
167 (81.07/12.98)
163 (12.70/80.69)
39 (18.93/19.31)
74
0.015
1148 (89.76/87.50)
164 (81.19/12.50)
131 (10.24/77.51)
38 (18.81/22.49)
74
<0.001
Social Support at 12 months
postpartum
Moderate or high support (>17)
Low support (<17)
909 (87.40/81.52)
206 (84.08/18.48)
131 (12.60/77.06)
39 (15.92/22.94)
283
0.167
937 (90.36/81.98)
206 (84.43/18.02)
100 (9.64/72.46)
38 (15.57/27.54)
283
0.007
Perceived Stress at 32-36 weeks
gestation
Low symptoms of stress (<19)
High symptoms of stress (>19)
1090 (86.99/82.76)
227 (85.34/17.24)
163 (13.01/80.69)
39 (14.66/19.31)
43
0.471
1117 (89.50/83.30)
224 (85.50/16.70)
131 (10.50/77.51)
38 (14.50/22.49)
43
0.061
Perceived Stress at 4 months
postpartum
Low symptoms of stress (<19)
High symptoms of stress (>19)
1115 (87.25/86.57)
173 (82.38/13.43)
163 (12.75/81.50)
37 (17.62/18.50)
75
0.055
1141 (89.49/87.10)
169 (82.44/12.90)
134 (10.51/78.82)
36 (17.56/21.18)
75
0.003
154
Perceived Stress at 12 months
postpartum
Low symptoms of stress (<19)
High symptoms of stress (>19)
876 (87.78/80.37)
214 (82.95/19.63)
122 (12.22/73.49)
44 (17.05/26.51)
312
0.041
898 (90.16/80.47)
218 (85.16/19.53)
98 (9.84/72.06)
38 (14.84/27.94)
312
0.022
Depression at 22-24 weeks gestation
No (<10)
Yes (>10)
1140 (87.16/84.88)
203 (84.23/15.12)
168 (12.84/81.55)
38 (15.77/18.45)
13
0.219
1163 (89.32/85.20)
202 (84.87/14.80)
139 (10.68/79.43)
36 (15.14/20.57)
13
0.047
Depression at 32-36 weeks gestation
No (<10)
Yes (>10)
1140 (87.22/85.78)
189 (83.63/14.22)
167 (12.78/81.86)
37 (16.37/18.14)
29
0.142
1163 (89.46/85.83)
192 (85.71/14.17)
137 (10.54/81.07)
32 (14.29/18.93)
29
0.099
Depression at 4 months postpartum
No (<10)
Yes (>10)
1171 (87.19/89.53)
137 (81.55/10.47)
172 (12.81/84.73)
31 (18.45/15.27)
50
0.043
1198 (89.54/90.01)
133 (80.61/9.99)
140 (10.46/81.40)
32 (19.39/18.60)
50
0.001
Pregnancy and Birth Outcome Factors
Number of days baby spent in
hospital after birth?
<3 days
>3 days
1097 (87.27/88.11)
148 (81.32/11.89)
160 (12.73/82.47)
34 (18.68/17.53)
123
0.028
1110 (88.80/87.61)
157 (86.26/12.39)
140 (11.20/84.85)
25 (13.74/15.15)
123
0.317
Antenatal Steroids?
Yes
No
30 (76.92/2.59)
1127 (87.57/97.41)
9 (23.08/5.33)
160 (12.43/94.67)
240
0.050
31 (79.49/2.66)
1133 (88.58/97.34)
8 (20.51/5.19)
146 (11.42/94.81)
240
0.081
Complications during pregnancy?
No
Yes
1262 (86.26/93.27)
91 (93.81/6.73)
201 (13.74/97.10)
6 (6.19/2.90)
0
0.034
1283 (88.24/93.31)
92 (94.85/6.69)
171 (11.76/97.16)
5 (5.15/2.84)
0
0.047
5-minute Apgar Scores
>7
<7
1193 (87.40/98.92)
13 (65.00/1.08)
172 (12.60/96.09)
7 (35.00/3.91)
181
0.003
1201 (88.57/98.69)
16 (80.00/1.31)
155 (11.43/97.48)
4 (20.00/2.52)
181
0.234
NICU admission?
No
Yes
1245 (87.12/92.02)
108 (82.44/7.98)
184 (12.88/88.89)
23 (17.56/11.11)
0
0.131
1266 (89.15/92.07)
109 (83.21/7.93)
154 (10.85/87.50)
22 (16.79/12.50)
0
0.040
Birth weight
None low birth weight (>2500g)
Low birth weight (<2500g)
1174 (86.96/94.75)
65 (77.38/5.25)
176 (13.04/90.26)
19 (22.62/9.74)
128
0.013
1194 (88.91/94.39)
71 (85.54/5.61)
149 (11.09/92.55)
12 (14.46/7.45)
128
0.347
155
Child Health Factors
Has your baby been diagnosed with
any long-term conditions?
Yes
No
66 (79.52/5.90)
1052( 87.38/94.10)
17 (20.48/10.06)
152 (12.62/89.94)
280
0.040
71 (85.54/6.20)
1074 (89.50/93.80)
12 (14.46/8.70)
126 (10.50/91.30)
280
0.260
Breasftfeeding at 12 months?
No
Yes
976 (87.69/72.14)
377 (84.34/27.86)
137 (12.31.66.18)
70 (15.66/33.82)
0
0.078
974 (88.22/70.84)
401 (89.71/29.16)
130 (11.78/73.86)
46 (10.29/26.14)
0
0.404
Communication Development at 12
months of age
On schedule
Delays
896 (87.76/95.93)
38 (66.67/4.07)
125 (12.24/86.81)
19 (33.33/13.19)
495
<0.001
918 (90.09/95.23)
46 (80.70/4.77)
101 (9.91/90.18)
11 (19.30/9.82)
495
0.024
Problem Solving Development at 12
months of age
On schedule
Delays
789 (88.26/84.75)
142 (78.45/15.25)
105 (11.74/72.92)
39 (21.55/27.08)
498
<0.001
816 (91.48/84.91)
145 (80.11/15.09)
76 (8.52/67.86)
36 (19.89/32.14)
498
<0.001
Personal-social Development at 12
months of age
On schedule
Delays
831 (88.40/89.16)
101 (74.26/10.84)
109 (11.60/75.69)
35 (25.74/24.31)
497
<0.001
855 (91.05/88.88)
107 (79.26/11.12)
84 (8.95/75.00)
28 (20.74/25.00)
497
<0.001
Fine Development at 12 months of
age
On schedule
Delays
854 (87.14/91.53)
79 (81.44/8.47)
126 (12.86/87.50)
18 (18.56/12.50)
496
0.116
887 (90.70/92.11)
76 (78.35/7.89)
91 (9.30/81.25)
21 (21.65/18.75)
496
<0.001
Communication Development at 12
months of age
On schedule
Delays
759 (90.90/81.35)
174 (71.90/18.65)
76 (9.10/52.78)
68 (28.10/47.22)
496
<0.001
753 (90.50/78.19)
210 (86.42/21.81)
79 (9.50/70.54)
33 (13.58/29.46)
496
0.067
Number of months between your
last child and this pregnancy
>24 months
<24 months
262 (85.62/37.86)
430 (88.30/62.14)
44 (14.38/43.56)
57 (11.70/56.44)
788
0.271
253 (83.50/36.72)
436 (90.08/63.28)
50 (16.50/51.02)
48 (9.92/48.98)
788
0.006
Partner smokes?
No
Yes
1149 (86.59/86.00)
187 (88.21/14.00)
178 (13.41/87.68)
25 (11.79/12.32)
24
0.517
1179 (89.25/86.88)
178 (85.17/13.12)
142 (10.75/82.08)
31 (14.83/17.92)
24
0.083
156
Did you breastfeed even for a short
time?
Yes
No
1283 (86.40/97.64)
31 (96.88/2.36)
202 (13.60/99.51)
1 (3.12/0.49)
44
0.085
1307 (88.49/97.76)
30 (93.75/2.24)
170 (11.51/98.84)
2 (6.25/1.16)
44
0.354
Community resource utilization at 4
months postpartum
<1
>1
310 (89.86/23.59)
1004 (85.67/76.41)
35 (10.14/17.24)
168 (14.33/82.76)
44
0.045
298 (86.88/22.29)
1039 (89.11/77.71)
45 (13.12/26.16)
127 (10.89/73.84)
44
0.254
Community resource utilization at
12 months postpartum
<1
>1
68 (89.47/6.20)
1028 (86.82/93.80)
8 (10.53/4.88)
156 (13.18/95.12)
307
0.506
62 (81.58/5.51)
1063 (90.08/94.49)
14 (18.42/10.69)
117 (9.92/89.31)
307
0.019
Community resource utilization at
24 months postpartum
<1
>1
265 (88.63/19.59)
1088 (86.28/80.41)
34 (11.37/16.43)
173 (13.72/83.57)
0
0.282
252 (84.28/18.33)
1123 (89.70/81.67)
47 (15.72/26.70)
129 (10.30/73.30)
0
0.008
Health Care Utilization at 4 months
postpartum
<1
>1
975 (87.76/78.06)
274 (82.28/21.94)
136 (12.24/69.74)
59 (17.72/30.26)
118
0.010
992 (89.77/77.62)
286 (86.40/22.38)
113 (10.23/71.52)
45 (13.60/28.48)
118
0.086
Abuse postpartum
No Abuse
Yes Abuse
1233 (87.01/94.63)
70 (78.65/5.37)
184 (12.99/90.64)
19 (21.35/9.36)
55
0.025
1252 (88.79/94.28)
76 (86.36/5.72)
158 (11.21/92.94)
12 (13.64/7.06)
55
0.486
Occasion when food didn’t last
Never
Often/Sometimes
1254 (86.66/95.43)
60 (86.96/4.57)
193 (13.34/95.54)
9 (13.04/4.46)
45
0.944
1281 (88.96/95.88)
55 (80.88/4.12)
159 (11.04/92.44)
13 (19.12/7.56)
45
0.041
Order of AOF child
Oldest/only child
Youngest/Middle
642 (86.06/47.49)
710 (87.33/52.51)
104 (13.94/50.24)
103 (12.67/49.76)
1
0.460
672 (90.44/48.91)
702 (86.99/51.09)
71 (9.56/40.34)
105 (13.01/59.66)
1
0.032
Does your child use your computer
at 24 months of age
Yes
No
774 (87.95/60.19)
512 (84.63/39.81)
106 (12.05/53.27)
93 (15.37/46.73)
77
0.064
789 (90.07/60.18)
522 (87.00/39.82)
87 (9.93/52.73)
78 (13.00/47.27)
77
0.066
157
4.3.2 Factors Associated with Delayed Gross Motor Development
Variables included in the original multivariable logistic regression model were as
follows: emotional health at 22-24 weeks gestation (p=0.044), emotional health at 32-36 weeks
gestation (p=0.054), social support at 32-36 weeks gestation (p=0.017), pregnancy complications
(p=0.034), number of days baby spent in hospital following birth (p=0.028), maternal postpartum
depression (p=0.043), maternal postpartum abuse (p=0.025), child health care utilization at 4
months of age (p=0.010), social support at 4 months postpartum (p=0.015), community resource
utilization at 4 months postpartum (p=0.045), maternal recreational drug use at 4 months
postpartum (p=0.010), and child gross (p<0.001), personal-social (p<0.001), problem solving
(p<0.001) and communication development (p<0.001) at 12 months of age.
The adjusted odds ratios of variables included in the final multivariable model are
presented in Table 9. The Hosmer-Lemeshow test did not suggest that the model was poorly
fitted (p=0.271). Children of mothers who experienced complications during pregnancy had 0.27
(95% CI: 0.08-0.93, p=0.038) times the odds of exhibiting gross motor delays at 24 months of
age, compared with children of mothers not experiencing complications during pregnancy.
Compared to children of mothers not experiencing abuse postpartum, children of abused mothers
exhibited a 2.32-fold (95% CI: 1.12-4.82, p=0.024) increase in the odds of exhibiting gross
motor delays at 24 months. Maternal use of recreational drugs at 12 months postpartum was also
associated with delayed gross motor development at 24 months of age (aOR: 4.23; 95% CI: 1.46-
12.2, p=0.008).
Developmental delays at 12 months of age were shown to be risk factors for gross motor
development at 24 months of age (Table 9). Children exhibiting gross motor delays at 12 months
of age had 3.46 (95% CI: 2.29-5.22, p<0.001) times the odds of exhibiting gross motor delays at
158
24 months of age. Moreover, children with delays in problem solving or communication
development at 12 months of age had 1.78 (95% CI: 1.11-2.87, p=0.017) or 2.69 (95% CI: 37-
5.29, p=0.004) times the odds of exhibiting gross motor delays at 24 months of age, compared
with children not experiencing delays at 12 months of age, respectively.
Table 9: Final multivariable logistic regression model of factors influencing gross motor
development at 24 months of age
Risk Factor Adjusted Odds Ratio
(95% CI) p-value
Poor maternal perception of overall emotional
health at 22-24 gestation 1.37 (0.61-3.09) 0.446
Poor maternal perception of overall emotional
health at 32-36 gestation 0.69 (0.27-1.75) 0.429
Pregnancy complications 0.27 (0.08-0.93) 0.038
Baby spent more than 3 days in the hospital
following birth 1.18 (0.66-2.10) 0.576
Maternal postpartum depression 1.57 (0.84-2.93) 0.157
Maternal postpartum abuse 2.32 (1.12-4.82) 0.024
Child required two or more health care services
prior to 4 months of age 1.52 (0.97-2.39) 0.069
Low social support at 4 months postpartum 1.36 (0.78-2.37) 0.278
Child exhibited delays in gross motor development
at 12 months of age 3.46 (2.29-5.22) <0.001
Child exhibited delays in problem solving
development at 12 months of age 1.78 (1.11-2.87) 0.017
Child exhibited delays in communication
development at 12 months of age 2.69 (1.37-5.29) 0.004
Maternal use of recreational drugs at 12 months
postpartum 4.23 (1.46-12.2) 0.008
159
4.3.3 Factors Associated with Delayed Fine Motor Development
Variables included in the multivariable logistic regression model were as follows:
maternal ethnicity (p<0.001), social support at 22-24 weeks gestation (p<0.001), social support
at 32-36 weeks gestation (p=0.010), pregnancy complications (p=0.047), if the baby was
admitted to the NICU (p=0.040), maternal perception of emotional health at 4 months
postpartum (p=0.008), maternal postpartum depression (p=0.001), maternal perceived stress at 4
months postpartum (p=0.003), social support at 4 months postpartum (p<0.001), food security at
4 months postpartum (p=0.041), social support at 12 months postpartum (p=0.007), community
resource utilization at 12 months postpartum (p=0.019), maternal alcohol consumption at 12
months postpartum (p=0.002), and child problem solving (p<0.001), personal-social (p<0.001),
communication (p=0.024) and fine motor development (p<0.001) at 12 months of age.
Children admitted to the NICU had 2.04 (95% CI: 1.06-3.92, p=0.032) times the odds of
exhibiting fine motor delays at 24 months of age, compared with children not admitted to the
NICU (Table 10). Furthermore, both problem solving (aOR: 2.32; 95% CI: 1.42-3.79, p=0.001)
and fine motor (aOR: 2.22; 95% CI: 1.22-4.03, p=0.009) developmental delays at 12 months of
age were risk factors for fine motor development at 24 months of age. Maternal alcohol
consumption at 12 months of age was also a risk factor for fine motor development. Children of
mothers consuming alcohol at 12 months postpartum had a 1.65-fold (95% CI:1.05-2.61,
p=0.031) increase in fine motor development delays compared with children of mothers not
consuming alcohol. Results from the Hosmer-Lemeshow test did not suggest that the model was
poorly fitted (p=0.669).
160
Table 10: Final multivariable logistic regression model of factors influencing fine motor
development at 24 months of age
Risk Factor Adjusted Odds Ratio
(95% CI) p-value
Low social support at 22-24 gestation 1.43 (0.69-2.95) 0.332
Low social support at 32-36 gestation 1.19 (0.57-2.49) 0.639
Baby was admitted to the NICU 2.04 (1.06-3.92) 0.032
Maternal postpartum depression 2.05 (0.96-4.39) 0.065
High symptoms of perceived stress at 4 months
postpartum 1.02 (0.49-2.14) 0.06
Low social support at 32-36 gestation 1.10 (0.54-2.24) 0.786
Child exhibited delays in problem solving
development at 12 months of age 2.32 (1.42-3.79) 0.001
Child exhibited delays in fine development at 12
months of age 2.22 (1.22-4.03) 0.009
Less than two community services used at 12
months postpartum 0.66 (0.31-1.41) 0.282
Maternal consumption of alcohol at 12 months
postpartum 1.65 (1.05-2.61) 0.031
4.4 Discussion:
Findings from this Canadian prospective cohort study suggest that risk factors for delayed
gross motor development at 24 month of age are as follows: delays in gross motor, problem
solving and communication development at 12 months, maternal postpartum abuse and maternal
illicit drug use at 12 months postpartum. Pregnancy complications were associated with a
reduction in risk for gross motor delays. Child admission to the neonatal intensive care unit
following birth, maternal consumption of alcohol at 12 months postpartum and delayed problem
solving and fine motor development at 12 months of age were associated with suboptimal fine
motor at 24 months of age.
161
Prenatal drug52,53,85,95,105,107,111,122 and alcohol52,53,72,79,95,103,104 exposure is a known risk
factor for delayed motor development. Few studies, however, have investigated the influence of
postnatal drug and alcohol exposure53,80,181. Using a sample of 400 infants, Little et al.
investigated the influence of alcohol, tobacco, caffeine and marijuana exposure via breastmilk181.
In their analysis, Little et al. described a dose-response relationship whereby increased alcohol
exposure via breastmilk was associated with decreased general motor development scores.
Similar cohort studies, however, have not been able to replicate these results80. As such, the
influence of maternal alcohol and illicit drug consumption at 12 month postpartum on motor
development as described in this study may not be directly due to postpartum alcohol
consumption, but rather a less biased estimate of maternal alcohol consumption during
pregnancy. As there is less social stigma of alcohol consumption prior to pregnancy or following
pregnancy, women may have been more likely to accurately report consumption at these two
time-point. In the All Our Families cohort, 46% of women consuming alcohol in the year prior to
pregnancy did not abstain from alcohol following pregnancy recognition194. Moreover, 13% of
all women reported at least one binge drinking episode that occurred prior to pregnancy
recognition, a prevalence lower than reported in other cohort studies. As such, future research
studies, designed to validate maternal reports of alcohol and drug consumption using laboratory
test, should explore the impact of these exposures postnatally on motor development.
The influence of intimate partner violence (IPV) on fine and gross motor development
has only recently been explored in the literature68. In this study, children of mothers having
experienced abuse in the postpartum period had 2.32 (95% CI: 1.12-4.82, p=0.024) times the
odds of exhibiting gross motor development delays. Similar results were described in an
American cross-sectional study of 16, 595 participants less than 72 months of age68. Children of
162
parents reporting both intimate partner violence and parental psychological distress (PPD) had a
three-fold increase in the odds of exhibiting gross motor delays, compared to children of parents
not reporting either IPV or PPD. Children of mothers only experiencing IPV, however, had
nearly a two-fold increase in the odds of exhibiting fine motor delays. As such, in addition to
screening for child abuse during primary care visits, identifying poor family interactions and
referring parents to supportive services, may help with preventing gross motor developmental
delays at 24-months of age.
The persistence of delays in gross motor development from 12-24 months of age
described in this study are consistent with the literature. In their examination of gross motor
development and joint hypermobility among 59 infants living in Israel, Tirosh et al. reported that
the prevalence of gross motor delays at 5 years was significantly higher among those who also
exhibited gross motor delays at 18 months156. Moreover, Burns et al. also described that motor
development at 12 months of age was a good predictor of motor development at 4 years of
age182.
In addition to the persistence of gross motor delays, our study found that delayed
communication development at 12 months of age significantly increased the odds of children
exhibiting gross motor delays at 24 months of age. It has been suggested that nearly 50% of kids
with developmental speech and language disorders also exhibit deficits in motor
development183,184. A proposed mechanism for this co-occurrence of delays has been described
as atypical brain development, where deviations in the basal ganglia may distort the balance
control and manual dexterity necessary for motor skills and, interfere with language production
and speech initiation183. These results, however, were obtained in cohorts of 23-125 children
163
aged 6-10 years183,184 and therefore our analysis provides the earliest evidence of an association
between early language development and later gross motor development.
This study is the first to describe an association between fine motor development at 12
and 24 months of age. The literature suggests that the influence of early fine motor development
on later motor attainment may not be persistent. In their analysis investigating the influence of
early motor development on later motor and cognitive abilities, Piek et al. described that fine or
gross motor development was not predictive of motor abilities at 6-12 years of age6. This
analysis, however, was limited to 33 children and therefore future large, longitudinal cohort
studies investigating the long-term influence of early motor delays are warranted. Moreover, as
motor development at 12 months of age was shown to be a risk factor for delayed motor
development at 24 months of age cohort studies such as ALSPAC or Target Kids should
investigate whether early developmental delays were risk factors for later motor delays among
their sample.
The association between personal-social development at 12 months of age and fine and
gross motor development at 24 months of age is a novel association. It can be speculated,
however, that this association may be due to the interplay between sensorimotor maturation and
the acquisition of cognitive skills7,8. Problem-solving development at 12 months of age is
measured using a variety of purposeful gross and fine motor tasks, such as placing multiple
objects into a box. If a child is experiencing fine or gross developmental delays, however, these
motor delays may limit the child’s ability to perform the purposeful movements involved in the
problem-solving tasks. Though this proposed mechanism is speculative, the importance of this
association is warranted. The literature suggests that co-occurring developmental delays in
children are generally more severe and persistent than independent delays61,62. As such, if a child
164
exhibits signs or symptoms of developmental delays in problem solving, communication, fine
motor or gross motor development at 12 months of age, the child should be referred to
developmental intervention programs for assessment, monitoring or intervention to reduce the
risk of further delay.
There is little theoretical evidence to suggest a protective effect for gross motor
development among children delivered from pregnancies that include complications such as
oligo/polyhydramnios, bleeding or premature rupture of membranes prior to 37 weeks gestation.
Rather, it is possible that the infants delivered from the complicated pregnancies did not have an
increased risk of gross motor delays, but received increased screening because of their
gestational history. As Canadian children delivered prematurely, with low birth weight or poor
measure of health status, receive the most consistent screening, children of complicated
pregnancies that may have exhibited early gross motor delays were identified at a young age and
provided appropriate interventions. As such, the apparent protective effect of pregnancy
complications may have been the result of improved screening measures. Conversely, our study
found that infants admitted to the NICU following birth had increased risk of experiencing fine
motor delays at 24 months of age. These results may suggest that infants admitted to the NICU
have an increased risk of fine motor delays, that may be associated with the reason for admission
and may be difficult to remediate through intervention.
Limitations of this study include the use of self-report questionnaires to collect detailed
information from the perinatal and early childhood period. The use of self-report questionnaires
are prone to biases related to recall and social desirability. To limit the effect of recall bias,
follow-up questionnaires were distributed frequently, with a maximum duration between surveys
of 12 months. Moreover, the potential effect of social desirability biases was reduced, as
165
exposures during pregnancy and early childhood were collected prior to the outcome variables
and were not associated with medical care. Finally, this study used a screening tool to assess
delays in fine and gross motor development rather than clinical assessment. The ASQ-3,
however, has strong psychometric properties and has been validated in a North American
sample. Furthermore, studies investigating the accuracy of parental report of child development
have shown that information provided by parents is highly accurate4.
The findings from this study contribute to the few studies investigating risk factors for
motor development among Canadian children. The prospective study design and large sample
size enabled the influence of a variety of relevant factors on fine and gross motor development to
be simultaneously assessed. The results from this study support the need for frequent, structured
primary care visits during the early childhood period, as recommended by the Canadian
Paediatric Society. Through these visits, parental concerns regarding development can be
explored, while primary care givers can assess developmental progression. Moreover, the
longitudinal nature of these visits would enable a strong physician-patient relationship to be
established, enabling physicians to assess potential sociodemographic, family interaction and
lifestyle factors demonstrated to influence fine and gross motor development. Ultimately, these
well-baby visits will enable children at risk of motor delays to be identified at 12 months of age
thereby allowing appropriate interventions to be initiated to support children in reaching their
developmental potential.
166
CHAPTER FIVE: CONCLUSIONS
5.1 Summary of Findings
Using data from the All Our Families (AOF) study, this study examined
sociodemographic, maternal health, birth outcome, child health and child environmental factors
influencing fine and gross motor development of Albertan children at 24 months of age. Of the
1595 participants included in this secondary analysis, 177 and 207 children were identified as
experiencing fine or gross motor delays, respectively.
Delays in gross motor, problem solving or communication development at 12 months
were associated with suboptimal gross motor development at 24 months of age. Maternal
postpartum abuse or illicit drug use at 12 months postpartum was also associated with gross
motor delays at 24 months of age. Pregnancy complications were associated with a reduction in
risk for gross motor delays at 24 months of age.
Child admission to the NICU following birth or maternal consumption of alcohol at 12
months postpartum were both associated with delays in fine motor development at 24 months of
age. Moreover, delayed problem solving or fine motor development at 12 months of age were
also associated with suboptimal fine motor development at 12 months of age. No factors
exhibiting a protective effect were found for fine motor development.
5.2 Limitations
There were several limitations with this study. First, detailed information on lifestyle,
mental health, family life and child development were collected during the perinatal and early
childhood period using self-report questionnaires. The use of self-report questionnaires to obtain
such information is prone to biases related to recall and social desirability. For example, in this
167
analysis healthcare and community service utilization during pregnancy and in the postpartum
period were assessed. Given the diversity of services available to participants and the
retrospective reporting of service utilization, these data are susceptible to recall bias. The
literature, however, suggests that recall of health care utilization is accurate between 6-12
months189. As such the effects of recall bias in this study were reduced by limiting the duration
between each follow-up questionnaire to a maximum of 12 months.
In addition to recall bias, reporting errors may have also occurred as select variables
included in this analysis did not specify time frames in their questions. For example, mothers
were asked for their height and weight prior to becoming pregnant. As the questionnaire did not
provide a specific time frame in the question, variability may exist in how each mother answered
the question. Moreover, the variability in these responses may have also influenced the
questionnaire’s assessment of gestational weight gain.
Self-report data may also be subject to biases related to social desirability. The effect of
social desirability may be especially prevalent in questions pertaining to mothers’ consumption
of alcohol, tobacco or illicit drugs during pregnancy; whereas the use of teratogenic substances
may be underreported. The potential effect of these biases are limited, however, as exposures
during pregnancy and early childhood were collected prior to outcome variables and were not
associated with medical care; therefore, women may be less influenced by social desirability
bias.
The categorization of mental health scales is another limitation of the current study.
When dichotomizing continuous variables, a substantial amount of information is lost190. For
example, this study used the Spielberger State-Trait Anxiety Inventory to assess anxiety191. The
State-Trait Anxiety inventory is composed of 40-items, each evaluated on a 4-point scale. In this
168
study, anxiety scores were dichotomized at a score of 40, where scores below 40 represented low
symptoms of anxiety and scores greater or equal to 40 represented high symptoms of anxiety.
Based on this dichotomization, scores of 1 and 39 were considered to be equal, whereas scores of
39 and 40 were considered unequal and represented a difference in anxiety. As such, information
related to participants with small difference in scores is lost. Moreover, the dichotomization of
variables also increased the probability of misclassifications, thereby increasing the risk of type
II error190. Despite these limitations, this study used dichotomized measures of depression,
anxiety, and social support as the dichotomization of these variables have increased clinical
relevance compared to the evaluation of continuous scores.
Lastly, the results from this study are limited in terms of generalizability. Participants of
the AOF study are generally representative of pregnant women and families in Canada with a
few exceptions: the AOF study reported a greater proportion of women: 1) attending prenatal or
childbirth educational classes, 2) over the age of 35, 3) with an annual income greater than
$40,000, 4) not experiencing postpartum depression, and 5) reporting their postpartum health as
fair or poor48. As such, the results from this study can be generalized to the urban pregnant and
parenting population in Canada. Given the sociodemographic and environmental differences
between the urban and rural population192, however, these results cannot be generalized to rural
Canadian families. Moreover, health care and community service accessibility must also be
considered when generalizing these results to similar populations outside of Canada.
5.3 Strengths
The use of community-based services such as primary and prenatal care offices and
Calgary Laboratory Service in the recruitment methodology reduced selection bias and supported
169
the enrollment of a sample reflective of the local pregnant and parenting community48. The AOF
study design also provided many strengths for this analysis. First, the large sample size included
in the cohort enabled the influence of many factors on motor development to be evaluated during
multivariable analysis. Second, the recency of the study ensured that factors being evaluated
were relevant to the local parenting community. Third, the intensive data collection strategy
employed by the AOF study enabled detailed information to be collected through the perinatal
and early childhood periods, while maintaining good response rates. Fourth, the prospective
nature of the study ensured temporality with regards to potential factors influencing fine and
gross motor development at 24 months of age.
The AOF study also provided a valid assessment of maternal health, birth and child
development outcomes. The use of scales such as the Spielberger State & Trait Anxiety Scale,
the Perceived Stress Inventory, Edinburgh Postnatal Depression Scale and the Centre for
Epidemiological Studies Depression Scale provided a valid estimation of maternal mental health.
Moreover, the use of electronic health records enabled the accuracy of maternal reports of birth
outcomes to be assessed. Finally, the high psychometric properties of the Ages and Stages
Questionnaires, along with its validity among a North American population reduced the potential
misclassification bias among our outcome variables.
5.4 Implications of Study Results
Identifying children with developmental delays remains the responsibility of health care
providers and caregivers of young children46. As delayed motor development is among the
earliest recognizable indicators of global developmental complications7,8, elucidating risk factors
of motor delays will support the identification of children at-risk of developmental delays. The
170
results from this study contribute to the few Canadian studies assessing the influence of
sociodemographic, biological and environmental factors on motor
development49,68,69,89,94,102,119,127,135,143-145. The identification of relevant risk factors of fine and
gross motor development in this study may assist both health care providers and caregivers of
young children in identifying children at increased risk of developmental delays at 12 months of
age. Moreover, the results of this study also provide support for the Canadian Pediatric Society’s
(CPS) recommendation for well-baby visits193. Well-baby visits establish a systematic, long-term
follow-up strategy for physicians to meet with children and families. Through these visits, the
CPS aims to ensure primary care visits inform parents of health resources available to them and
promote healthy behaviours. As our study suggests that maternal lifestyle factors, such as
postpartum drug and alcohol consumption at 12 months postpartum, are associated with later
motor development repercussion, well-baby visits would provide an optimal platform for
discussing this with parents. Furthermore, the longitudinal nature of well-baby visits would allow
physicians to establish a strong rapport with families63,193. Through this relationship, family
interaction risk factors, such as maternal postpartum abuse, can be assessed to ensure children
are appropriately monitored.
The results obtained in this study also support the continued assessment of motor
development in the AOF cohort. The identification of pregnancy, birth and maternal factors
influencing delayed motor development highlights the importance of investigating factors
throughout the perinatal and early childhood period. Moreover, given the influence of child
development at 12 months on later fine and gross motor development, trajectory analyses are
warranted. The results from this study may also inform future research related to school-
readiness and factors predicting injuries.
171
5.5 Recommendations for Future Research
Given the influence of child development at 12 months on later fine and gross motor
development as described by this study, trajectory analyses of development are warranted. In
their analysis investigating the influence of early motor development on later motor and
cognitive abilities, Piek et al. described that fine or gross motor development at 2 years of age
was not predictive of motor abilities at 6-12 years of age6. This analysis, however, was limited to
33 children and therefore future large, longitudinal cohort studies investigating the long-term
influence of early motor delays along with diverse covariates are needed. As the AOF study is
continuing to follow-up with children at 3, 5 and 8 years of age, this cohort would provide a
unique opportunity to access the long-term influence of early development on later abilities.
Future research should also target the influence of postnatal maternal alcohol, tobacco
and illicit drug use on child motor development. Fetal exposure to alcohol, tobacco and illicit
drugs is a known risk factor for suboptimal motor development90,120-122,127,129,130,133,134,154,
however, few studies have examined the influence of these exposures in the postnatal
period80,181. Our study is the first to describe an association between maternal consumption of
alcohol and recreational drugs at 12 months postpartum on fine and gross motor development,
respectively. However, maternal self-report of substance use could not be validated using
diagnostic tools. As such, future research studies, designed to validate maternal reports of
alcohol and drug consumption using laboratory test, should explore the impact of these postnatal
exposures on motor development.
Finally, few cohort studies have exclusively investigated the motor development of
minority or rural children72,77,95,108,117,138,147,161. The literature, along with the results of bivariate
analysis in the current study, suggests that ethnicity59,69,138, immigrant status, socioeconomic
172
status and community engagement influence motor development. To understand the influence of
cultural expectations of motor skills and the sociodemographic profile of immigrant and rural
families on motor development, future research must increase the inclusion of minorities and
rural children in studies examining motor development.
173
REFERENCES:
References:
1. Edwards SL, Sarwark JF. Infant and Child Motor Development. Clinical Orthopaedics
and related Research. 2005;434:33-39.
2. Boyle CA, Boulet S, Schieve L, Cohen RA, Blumberg SJ, Yeargin-Allsopp M, Visser S,
Kogan MD. Trends in the Prevalence of Developmental Disabilities in US Children,
1997-2008. Pediatrics. 2011;127(6):1034-42.
3. Mackrides PS, Ryherd SJ. Screening for Developmental Delay. American Family
Physician. 2001;84(5):544-549.
4. Glascoe FP. Screening for Developmental and Behavioural Problems. Mental
Retardation and Developmental Disabilities. 2005;11:173-179.
5. Noritz GH, Murphy NA, Neuromotor Screening Expert Panel. Motor Delays: Early
Identification and Evaluation. Pediatrics. 2013;131:e2016-2027.
6. Piek JP, Dawson L, Smith LM, Gasson N. The role of early fine and gross motor
development on later motor and cognitive ability. Human Movement Science.
2008;27:668-681.
174
7. Oudgenoeg O, Leseman PPM, Volman MJM. Exploration as a Mediator of the
Relationship Between the Attainment of Motor Milestones and the Development of
Spatial Cognition and Spatial Language. Developmental Psychology. 2015;51(9):1241-
1253.
8. Bellman M, Byrne O, Sege R. Developmental assessment of children. BMJ. 2013;
346:e8687.
9. Gerber J, Wilks T, Erdie-Lalena C. Developmental Milestones: Motor Development.
Pediatrics in Review. 2010;31(7):267-276.
10. Halpenny AM, Pettersen J. Introducing Early Years Thinkers: Introducing Piaget: A
guide for practitioners and students in early years education. Routledge. 2013
11. Piek JP. Infant motor development. Champaign: Human Kinetics; c2006.
12. Bushnell EW, Boudreau JP. Motor Development and the Mind: The Potential Role of
Motor Abilities as a Determinant of Aspects of Perceptual Development. Child
Devleopment. 1993;64(4):1005:1021.
13. Wijnroks L, van Veldhoven N. Individual differences in postural control and cognitive
development in preterm infants. Infant Behavior and Development. 2003;26:14-26.
175
14. Siegler R, Deloache J, Eisenberg N. How Children Develop. New York: Worth
Publishers; c2006.
15. Thelen E, Adolph KE. Arnold L. Gesell: The Paradox of Nature and Nurture.
Developmental Psychology. 1992;28(3):368:380.
16. Thelen E. Motor development as foundation and future of developmental psychology.
International Journal of Behavioral Development. 2000;24(4):385-397.
17. Dalton TC. Myrtle McGraw, the Maturation Debate and Aftermath. In: The Life Cycle of
Psychological Ideas: Understanding Prominence and the Dynamics of Intellectual
Change. New York: Kluwer Academic Publishers; c2004.
18. Gottlieb G. Myrtle McGraw’s unrecognized conceptual contribution to developmental
psychology. Developmental Review. 1998;18:437-448.
19. Dewey D, Tupper DE. Developmental Motor Disorders: A Neuropsychological
Perspective. New York: The Guilford Press; c2004.
20. Latash ML. Neuropsychological Basis of Movement. Champaign: Human Kinetics;
c2008.
176
21. Thelen E. Dynamic systems theory and the complexity of change. Psychoanalytic
Dialogues. 2005;15: 255-283.
22. Spencer JP, Clearfield M, Corbetta D, Ulrich B, Buchanan P, Schöner G. Moving toward
a grand theory of development: In memory of Esther Thelen. Child Development.
2006;77:1521-1538.
23. Malina RM. Motor development during Infancy and Early Childhood: Overview and
Suggested Directions for Research. International Journal of Sport and Health Science.
2004;2:50-66.
24. Wyke B. The neurological basis of movement – a developmental review. In: Movement
and child development: Clinics in developmental medicine. Philadelphia:
Lippincott;c1975.
25. Kail RV. Children and their Development, 6th edition. New Jersey: Pearson; c2012.
26. Allen MC, Capute AJ. The Evolution of Primitive Reflexes in Extremely Premature
Infants. Pediatric Research. 1986;20(12):1284-1289.
27. Zafeiriou DI. Primitive Reflexes and Postural Reactions in the Neurodevelopmental
Examination. Pediatric Neurology. 2004;31(1):1-8.
177
28. Sroufe LA, Cooper RG, Dehart GB. Child Development: Its Nature and Course, 3rd
edition. New Baskerville: Mcgraw-Hill, Inc; c1996.
29. Blasco PA. Primitive Reflexes: Their Contribution to the Early Detection of Cerebral
Palsy. Clinical Pediatrics.1994;33:388-397.
30. Sun H, Jensen R. Body Segment Growth during Infancy. Journal of Biomechanics.
1994;27(3):265-275.
31. American Psychological Association Dictionary of Clinical Psychology. Washington:
American Psychological Association; 2013. Gross motor; 260-261.
32. Wijnhoven TMA, de Onis M, Onyango AW, Want T, Bjoerneboe GEN, Bhandari N,
Lartney A, Al Rashidi B. Assessment of gross motor development in the WHO
Multicentre Growth Reference Study. Food and Nutrition Bulletin. 2004;25 (1
Suppl):S37-45.
33. WHO Multicentre Growth Reference Study Group. WHO Motor Development Study:
Windows of achievement for six gross motor development milestones. Acta Paediatrica.
2006;450:86-95.
34. American Psychological Association Dictionary of Clinical Psychology. Washington:
American Psychological Association; 2013. Fine motor; 236.
178
35. Glass P. Development of visual function in preterm infants: Implications for early
intervention. Infants & Young Children. 1993;6(1):11-20.
36. Boyle CA, Boulet S, Schieve L, Cohen RA, Blumberg SJ, Yeargin-Allsopp M, Visser S,
Kogan MD. Trends in the Prevalence of Developmental Disabilities in US Children,
1997-2008. Pediatrics. 2011;127(6):1034-42.
37. Tervo RC. Identifying Patterns of Developmental Delays Can Help Diagnose
Neurodevelopmental Disorders. Clinical Pediatrics. 2006;45:509-517.
38. Lewis G, Sheringham J, Bernal JL, Crayford T. Mastering Public Health: A Postgraduate
Guide to Examinations and Revalidation, 2nd edition. Boca Raton: CRC Press, Taylor and
Francis Group; c2015.
38. Rydz D, Shevell MI, Majnemer A, Oskoui M. Developmental Screening. Journal of
Child Neurology. 2005;20(1):5-21.
39. Mueller M, Towne RC, Pollaro R. Infant Assessment. New York: Perseus Books, LLC;
1997.
179
40. Montgomery PC, Connolly BH. Norm-Referenced and Criterion-Referenced Tests Use in
Pediatrics and Application to Task Analysis of Motor Skill. Physical Therapy.
1988;67(12):1873-1876.
41. Ringwalt S. Developmental Screening and Assessment Instruments with an Emphasis on
Social and Emotional Development for Young Children Ages Birth through Five. Chapel
Hill: The National Early Childhood Technical Assistance Center: 2008.
42. Mackrides PS, Ryherd SJ. Screening for Developmental Delay. American Family
Physician. 2001;84(5):544-549.
43. Piper MC, Pinnell LE, Darrah J, Maguire T, Byrne PJ. Construction and validation of the
Alberta Infant Motor Scale (AIMS). Canadian Journal of Public Health. 1992;83(Suppl
2):S46-50.
44. Harris SR. Parents’ and caregivers’ perceptions of their children's development.
Developmental Medicine & Child Neurology. 1994;36(10):918-923.
45. Bodnarshuk JL, Eaton WO. Can parent reports be trusted?: Validity of daily checklists of
gross motor milestone attainment. Journal of Applied Developmental Psychology.
2004;25(4):481-490.
180
45. Wilson JMG, Jungner G. Principles and Practice of Screening for Disease. World Health
Organization Public Health Papers. 1968;34:1-163.
46. Canadian Task Force on Preventive Health Care. Recommendations on screening for
developmental delay. Canadian Medical Association Journal. 2016;188(8):579-587.
47. Grantham-McGregor S, Cheung YB, Cueto S, Glewwe P, Richter L, Strupp B, the
International Child Development Steering Group. Developmental potential in the first 5
years for children in developing countries. Lancet. 2007; 369(9555): 60–70.
48. McDonald SW, Lyon AW, Benzies KM, McNeil DA, Lye SJ, Dolan SM, Pennell CE,
Bocking AD, Tough SC. The All Our Babies pregnancy cohort: design, methods, and
participant characteristics. BMC Pregnancy and Childbirth. 2013;13(Suppl 1):1-12.
49. Abbott AL, Bartlett DJ, Fanning JEK, Kramer J. Infant Motor Development and Aspects
of the Home Environment. Pediatric Physical Therapy. 2000;12:62-67.
50. Abbott AL, Bartlett DJ. Infant motor development and equipment use in the home. Child:
Care, Health and Development. 2001; 27(3): 295-306.
51. Aiello R, Lancaster S. Influence of Adolescent Maternal Characteristics on Infant
Development. Infant Mental Health Journal. 2007;28(5):496-516.
181
52. Arendt R, Singer L, Angelopoulos J, Bass-Busdiecker O, Mascia J. Sensorimotor
Development in Cocaine-exposed Infants. Infant Behaviour and Development. 1998;
21(4):627-640.
53. Astley SJ, Little RE. Maternal Marijuana Use During Lactation and Infant Development
at One Year. Neurotoxicology and Teratology. 1990;12:161-168.
54. Aylward EH, Butz AM, Hutton N, Joyner ML, Vogelhut JW. Cognitive and Motor
Development in Infants at Risk for Human Immunodeficiency Virus. AJDC.
1992;146:218-222.
55. Bedford R, Saez de Urabain IR, Cheung CHM, Karmiloff-Smith A, Smith TJ. Toddlers’
Fine Motor Milestone Achievement Is Associated with Early Touchscreen Scrolling.
Frontiers in Psychology. 2016;7:1-8.
56. Belfort MB, Rifas-Shiman S, Sullivan T, Collins CT, McPhee AJ, Ryan P, Kleinman KP,
Gillman MW, Gibson RA, Makrides M. Infant Growth Before and After Term: Effects
on Neurodevelopment in Preterm Infants. Pediatrics. 2011;128(4):e899-e906.
57. Bendersky M, Lewis M. Environmental Risk, Biological Risk, and Development
Outcome. Development Psychology. 1994;30(4): 484-494.
182
58. Black MM, Nitz K. Grandmother Co-Residence, Parenting, and Child Development
Among Low Income, Urban Teen Mothers. Journal of Adolescent Health. 1996;18:218-
226.
59. Brown CW, Olson HC, Croninger RG. Maternal Alcohol Consumption During
Pregnancy and Infant Social, Mental and Motor Development. Journal of Early
Intervention. 2010;32(2):110-126.
60. Casper RC, Gilles AA, Fleisher BE, Baran J, Enns G, Lazzeroni LC. Length of prenatal
exposure to selective serotonin reuptake inhibitor (SSRI) antidepressants: effects on
neonatal adaptation and psychomotor development. Psychopharmacology. 2011;217:211-
219.
61. Cohen MJ, Meadoe KJ, Browning N, Baker GA, Calyton-Smith J, Kalayjian LA, Kanner
A, Piporace JD, Pennell PB, Privitera M, Loring DW. Fetal antiepileptic drug exposure:
Motor, adaptive, and emotional/behavioral functioning at age 3 years. Epilepsy &
Behavior. 2011;22:240-246
62. Daniels JL, Longnecker MP, Klebanoff MA, Gray KA, Brock JW. Zhou H, Chen Z,
Needham LL. Prenatal Exposure to Low-Level Polychlorinated Biphenyls in Relation to
mental and Motor Development at 8 Months. American Journal of Epidemiology.
2003;157(6):485-492.
183
63. Datar A, Jacknowitz A. Birth Weight Effects on Children’s Mental, Motor, and Physical
Development: Evidence from Twins Data. Maternal and Child Health Journal.
2009;13:780-794.
64. Dudek-Shriber L, Zelazny S. The Effects of Prone Positioning on the Quality and
Acquisition of Developmental Milestones in Four-Month-Old Infants. Pediatric Physical
Therapy. 2007;19:48-55.
65. Espel EV, Glynn LM, Sandman CA, Davis EP. Longer Gestation among Children Born
Full Term Influences Cognitive and Motor Development. PLOS ONE. 2014;9(11):1-13.
66. Fanaroff AA, Fanaroff JM. Short- and Long-Term Consequences of Hypotension in
ELBW Infants. Seminars in Perinatology. 2006;30:151-155.
67. Fetters L, Huang H. Motor development and sleep, play, and feeding positions in very-
low-birthweight infants with and without white matter disease. Development Medicine &
Child Neurology. 2007;49:807-813.
68. Gilbert AL, Bauer NS, Carroll AE, Downs SM. Child Exposure to Parental Violence and
Psychological Distress Associated With Delayed Milestones. Pediatrics.
2013;132(6):e1577-e1583.
184
69. Hediger ML, Overpeck MD, Ruan WJ, Troendle JF. Birthweight and gestational age
effects on motor and social development. Paediatric and Perinatal Epidemiology.
2002;16:33-46.
70. Hinkle SN, Schieve LA, Stein AD, Swan DW, Ramakrishnan U, Sharma AJ.
Associations between maternal prepregnancy body mass index and child
neurodevelopment at 2 years of age. International Journal of Obesity. 2012;36:1312-
1319.
71. Huizink AC, Robles de Medina PG, Mulder EJH, Visser GHA, Buitelaar JK. Stress
during pregnancy is associated with developmental outcome in infancy. Journal of Child
Psychology and Psychiatry. 2003;44(6):810-818.
72. Jacobson JL, Jacobson SW, Sokol RJ, Martier SS, Ager JW, Kaplan-Estrin MG.
Teratogenic Effects of Alcohol on Infant Development. Alcoholism: Clinical and
Experimental Research. 1993;17(1):174-183.
73. Janssen AJWM, Akkermans RP, Steiner K, de Haes OAM, Oostendorp RAB, Kollee
LAA, Nijhuis-van der Sanden MWG. Unstable longitudinal motor performance in
preterm infants from 6 to 24 months on the Bayley Scales of Infant Development –
Second Edition. Research in Developmental Disabilities. 2011;32:1902-1909.
185
74. Johnson KC, LaPrairie JL, Brennan PA, Stowe ZN, Newport DJ. Prenatal Antipsychotic
Exposure and Neuromotor Performance During Infancy. Archives of General Psychiatry.
2012;69(8):787-794.
75. Julvez J, Fortuny J, Mendez M, Torrent M, Ribas-Fito N, Sunyer, J. Maternal use of folic
acid supplements during pregnancy and four-year-old neurodevelopment in apopulation-
based birth cohort. Paediatric and Perinatal Epidemiology. 2009;23:199-206.
76. Kanazawa H, Kawai M, Niwa F, Hasegawa T, Iwanaga K, Ohata K, Tamaki A, Heiki T.
Subcutaneous fat accumulation in early infancy is more strongly associated with motor
development and delay than muscle growth. ACTA Paediatrica. 2014;103:e262-e267.
77. Kaplan-Estrin M, Jacobson SW, Jacobson JL. Neurobehavioral Effects of Prenatal
Alcohol Exposure at 26 Months. Neurotoxicology and Teratology. 1999;21(5):503-511.
78. Kato T, Mandai T, Iwatani S, Koda T, Nagasaka , Fujita K, Kurokawa D, Yamana K,
Nishida K, Taniguchi-Ikeda M, Tanimura K, Deguchi M, Yamada H, Iijima K, Morioka
I. Extremely preterm infants small for gestation age are at risk for motor impairment at 3
years corrected age. Brain & Development. 2016;38:188-195.
79. Larroque B, Kaminski M, Dehaene P, Subtil D, Delfosse M, Querleu D. Moderate
Prenatal Alcohol Exposure and Psychomotor Development at Preschool Age. American
Journal of Public Health. 1995;85(12):1654-1661.
186
80. Little RE, Northstone K, Golding J, ALSPAC Study Team. Alcohol, Breastfeeding, and
Development at 18 Months. Pediatrics. 2002;109(5):1-6.
81. Mazer P, Gischler SJ, Van Der Cammen-Van Zijp MHM, Tibboel D, Bax NMA,
Ijsselstijn H, Van Dijk M, Duivenvoorden HJ. Early developmental assessment of
children with major non-cardiac congenital anomalies predicts development at the age of
5 years. Developmental Medicine & Child Neurology. 2010;52(12):1154-1159.
82. Messinger DS, Bauer CR, Das A, Seifer R, Lester BM, Lagasse LL, Wright LL,
Shankaran S, Bada HS, Smeriglio VL, Langer JC, Beeghly M, Poole WK. The Maternal
Lifestyle Stud: Cognitive, Motor, and Behavioral Outcomes of Cocaine-Exposed and
Opiate-Exposed Infants Through Three Years of Age. Pediatrics. 2004;113(6):1677-
1685.
83. Mellins CA, Levenson RL Jr, Zawadzki R. Effects of Pediatric HIV Infection and
Prenatal Drug Exposure on mental and Psychomotor Development. Journal of Pediatric
Psychology. 1994;19(5):617-628.
84. Mendez MA, Torrent M, Julvez J, Ribas-Fito N, Kogevinas M, Sunyer J. Maternal fish
and other seafood intakes during pregnancy and child neurodevelopment at age 4 years.
Public Health Nutrition. 2008;12(10):1702-1710.
187
85. Miller-Loncar C, Lester BM, Seifer R, Lagasse LL, Bauer CR, Shankaran S, Bada HS,
Wright LL, Smeriglio VL, Bigsby R, Liu J. Predictors of motor development in children
prenatally exposed to cocaine. Neurotoxicology and Teratology. 2005;27:213-220.
86. Minguez-Milio, JA, Alcazar JL, Auba M, Ruiz-Zambrana A, Minguez J. Perinatal
outcome and long-term follow-up of extremely low birth weight infants depending on the
mode of delivery. The Journal of Maternal-Fetal & Neonatal Medicine.
2011;24(10):1235-1238.
87. Mulligan L, Specker BL, Buckley DD, O’Connor LS, Ho M. Physical and Environmental
Factors Affecting Motor Development, Activity Level, and Body Composition of Infants
in Child Care Centers. Pediatric Physical Therapy. 1998;10:156-161.
88. Nakajima S, Saijo Y, Kato S, Sasaki S, Uno A, Kanagami N, Hirakawa H, Hori T,
Tobiishi K, Ta=]odaka T, Nakamura Y, Yanagiya S, Sengoku Y, Lida T, Sata F, Kishi R.
Effects of Prenatal Exposure to Polychlorinated Biphenyls and Dioxins on Mental and
Motor Development in Japanese Children at 6 Months of Age. Environmental Health
Perspectives. 2006;114(5):773-778.
89. Nash A, Dunn M, Asztalos E, Corey M, Mulvihill-Jory B, O’Connor DL. Pattern of
growth of very low birth weight preterm infants, assessed using the WHO Growth
Standards, is associated with neurodevelopment. Applied Physiology, Nutrition and
Metabolism. 201;36:562-569.
188
90. Nelson, S, Lerner E, Needlman R, Salvator A, Singer LT. V=Cocaine, Anemia, and
Neurodevelopmental Outcomes in Children: A Longitudinal Study. Journal of
Developmental and Behavioural Pediatrics. 2004;25(1):1-9.
91. Ohman A, Nilsson S, Lagerkvist A. Are infants with torticollis at risk of a delay in early
motor milestones compared with a control group of healthy infants? Development
Medicine & Child Neurology. 2009;51(7):545-550.
92. Polanska K, Muszynski P, Sobala W, Dziewirska E. Maternal lifestyle during pregnancy
and child psychomotor development – Polish Mother and Child Cohort study. Early
Human Development. 2015;91:317-325.
93. Ratliff-Schaub K, Hunt CE, Crowell D, Golub H, Smok-Pearsall S, Palmer P, Schafer S,
Bak S, Cantey-Kiser J, O’Bell R, CHIME Study Group. Relationship Between Infant
Sleep Position and Motor Development in Preterm Infants. Development and Behavioral
Pediatrics. 2001;22(5):293-299.
94. Ravenscroft EF, Harris SR. Is Maternal Education Related to Infant Motor Development?
Pediatric Physical Therapy. 2007;19:56-61.
189
95. Richardson GA, Goldschmidt L, Willford J. The Effects of Prenatal Cocaine Use on
Infant Development. Neurotoxicology and Teratology. 2008;30(2):96-106.
96. Ronfani L, Brumatti L, Mariuz M, Tognin V, Bin M, Ferluga V, Knowles A, Montico M,
Barbone F. The Complex Interaction between Home Environment, Socioeconomic
Status, Maternal IQ and Early Child Neurocognitive Development: A Multivariate
Analysis of Data Collected in a Newborn Cohort Study. PLOS ONE. 2015;10(5):1-13.
97. Sansavini A, Rizzardi M, Alessandroni R, Giovanelli G. The development of Italian
Low- and Very-low-birthweight Infants from Birth to 5 Years: The Role of Biological
and Social Risks. International Journal of Behavioral Development. 1996;19(3):533-547.
98. Santos NF, Costa RA. Parental tobacco consumption and child development. Jornal de
Pediatria. 2015;91(4):366-372.
99. Scher A, Tse L, Hayes VE, Tardif M. Sleep Difficulties in Infants at Risk for
Developmental Delays: A Longitudinal Study. Journal of Pediatric Psychology.
2008;33(4):396-405.
100. Schuler ME, Nair P, Kettinger L. Drug-Exposed Infants and Developmental Outcome.
Archives of Pediatrics and Adolescent Medicine. 2003;157:133-138.
190
101. Serenius F, Kalle K, Blennow M, Ewald U, Fellman V, Holmstrom G, Lindberg E,
Lundqvist P, Marsal K, Norman M, Olhager E, Stigson L, Stjernqvist K, Vollmer B,
Stromberg B. Neurodevelopmental Outcome in Extremely Preterm Infants at 2.5 Years
After Active Perinatal Care in Sweden. JAMA. 2013;309(17):1810-1820.
102. Sherlock RL, Synnes AR, Koehoorn M. Working mothers and early childhood outcomes:
Lessons from the Canadian National Longitudinal study on children and youth. Early
Human Development. 2008;84:237-242.
103. Singer LT, Moore DG, Fulton S, Goodwin J, Turner JJD, Min MO, Parrott AC.
Neurobehavioral outcomes of infants exposed to MDMA (Ecstasy) and other recreational
drugs during pregnancy. Neurotoxicology and Teratology. 2012;34:303-310.
104. Singer LT, Moore DG, Min MO, Goodwin J, Turner JJD, Fulton S, Parrott AC. One-
Year Outcomes of Prenatal Exposure to MDMA and Other Recreational Drugs. Pediatrics.
2012;130(3):407-413.
105. Singer LT, Moore DG, Min MO, Goodwin J, Turner JDD, Fulton S, Parrott AC. Motor
delays in MDMA (ecstacy) exposed infants persist to 2 years. Neurotoxicology and
Teratology. 2016;54:22-28.
106. Singer L, Yamashita T, Lilien L, Collin M, Baley J. A Longitudinal Study of
development Outcome of Infants with Bronchopulmonary Dysplasia and Very Low Birth
Weight. Pediatrics. 1997;100(6):987-993.
191
107. Singer LT, Yamashita TS, Hawkins S, Cairns D, Baley J, Kliegman R. Increased
incidence of intraventricular hemorrhage and developmental delay in cocaine-exposed,
very low birth weight infants. Journal of Pediatrics. 1994;124(5 0 1):765-771.
108. Slining M, Adair LS, Goldman BD, Borja JB, Bentley M. Infant Overweight is
Associated with Delayed Motor Development. The Journal of Pediatrics. 2010;157:20-25.
109. Smith R, Malee K, Charurat M, Magder L, Mellins C, MacMillan C, Hittleman J, Lasky
T, Llorente A, Jack M. Timing of perinatal human immunodeficiency virus type 1
infection and rate of neurodevelopment. The Pediatric Infectious Disease Journal.
2000;19(9):862-871.
110. Stanton WR, McGee R, Silva PA. Indices of Perinatal Complications, Family
Background, Child Rearing, and Health as Predictors of Early Cognitive and Motor
Development. Pediatrics. 1991;88(5):954-959.
111. Swanson MW, Streissguth AP, Sampson PD, Olson HC. Prenatal Cocaine and
Neuromotor Outcome at Four Months: Effects of Duration of Exposure. Developmental
and Behavioral Pediatrics. 1999;20(5):325-334.
192
112. Tauman R, Zuk L, Uliel-Sibony S, Ascher-Landsberg J, Katsav S, Farber M, Sivan Y,
Bassan H. The effect of maternal sleep-disordered breathing on the infant’s
neurodevelopment. American Journal of Obstetrics & Gynecology. 2015;212:656.e1-7.
113. Trasti N, Vik T, Jacobsen G, Bakketeig LS. Smoking in pregnancy and children’s mental
and motor development at age 1 and 5 years. Early Human Development. 1999;55:137-
147.
114. Valtonen R, Ahonen T, Lyytinen P, Lyytinen H. Co-occurrence of developmental delays
in a screening study of 4-year-old Finnish children. Developmental Medicine & Child
Neurology. 2004;46:436-443.
115. Van der Sluijs Veer L, Kempers MJE, Wiedijk BM, Last BF, Grootenhuis MA, Vulsma
T. Evaluation of Cognitive and Motor Development in Toddlers with Congenital
Hypothyroidism Diagnosed by Neonatal Screening. Journal of Developmental and
Behavioural Pediatrics. 2012;33(8):633-640.
116. Vilahur N, Fernandez MF, Bustamante M, Ramos R, Forns J, Ballester F, Murcia M,
Riano I, Ibarluzea J, Olea N, Sunyer J. In Utero exposure to mixtures of xenoestrogens and
child neuropsychological development. Environmental Research. 2014;134:98-104.
193
117. Wehby G, Murray JC. The Effects of Prenatal Use of Folic Acid and Other Dietary
Supplements on Early Child development. Maternal and Child Health Journal.
2008;12:180-187.
118. Wouldes TA, LaGasse LL, Huestis MA, Della Grotta S, Dansereau M, Lester BM.
Prenatal methamphetamine exposure and neurodevelopmental outcomes in children from 1
to 3 years. Neurotoxicology and Teratology. 2014;42:77-84.
119. Zwicker JG, Yoon SW, MacKay M, Petrie-Thomas J, Rogers M, Synnes AR. Perinatal
and neonatal predictors of developmental coordination disorder in very low birthweight
chikdren. Archives of Diseases in Childhood. 2013;98:118-122.
120. McLean E, de Benoist B, Allen LH. Review of the magnitude of folate and vitamin B12
deficiencies worldwide. Food and Nutrition Bulletin. 2008. 29(2):s38-51.
120. Arendt R, Angelopoulos J, Salvator A, Singer L. Motor Development of Cocaine-
exposed Children at Age Two Years. Pediatrics. 1999;103(1):86-92.
121. Austin M, Karatas JC, Mishra P, Christl B, Kennedy D, Oei J. Infant neurodevelopment
following in utero exposure to antidepressant medication. ACTA Paediatrica.
2013;102:1054-1059.
194
122. Bigsby, R, LaGrasse LL, Lester B, Shankaran S, Bada, H, Bauer C, Liu J. Prenatal
Cocaine Exposure and Motor Performance at 4 Months. American Journal of Occupational
Therapy. 2011;65(5):1-17.
123. Case-Smith J. Postural and Fine Motor Control in Preterm Infants in the First Six
Months. Physical & Occupational Therapy in Pediatrics. 1993;13(1):1-17.
124. Carmeli E, Marmur R, Cohen A, Tirosh E. Preferred sleep position and gross motor
achievement in early infancy. European Journal of Pediatrics. 2009;168:711-715.
125. Cruise S, O’Reilly D. The influence of parents, older siblings, and non-parental care on
infant development at nine months of age. Infant Behaviors & Development. 2014;37:546-
555.
126. De Kegel A, Maes L, Dhooge I, van Hoecke H, De Leenheer E, Van Waelvelde H. Early
motor development of children with congenital cytomegalovirus infection. Research in
Developmental Disabilities. 2016;48:253-261.
127. Eek Brandlistuen R, Ystrom I, Koren I, Nordeng H. Prenatal paracetamol exposure and
child neurodevelopment: a sibling-controlled cohort study. International Journal of
Epidemiology. 2013;42:1702-1713.
195
128. Evlampidou I, Bagkeris M, Vardavas C, Koutra K, Patelarou E, Koutis A, Chatzi L,
Kogevinas M. Prenatal Second-Hand Smoke Exposure Measured with Urine Cotinine May
Reduce Gross Motor Development at 18 Months of Age. The Journal of Pediatrics.
2015;167:246-252.
129. Galbally M, Lewis AJ, Buist A. Developmental outcomes of children exposed to
antidepressants in pregnancy. Australian and New Zealand Journal of Psychiatry.
2011;45:393-399.
130. Ghassabian A, Sundaram R, Wylie A, Bell, E, Bello SC, Yeung E. Maternal medical
conditions during pregnancy and gross motor development up to age 24 months in the
Upstate KIDS study. Development Medicine & Child Neurology. 2015;58:728-734.
131. Gonzalez-Valenzuela M, Lopez-Montiel D, Gonzales-Mesa ES. Exposure to Synthetic
Oxytocin During Delivery and Its Effect on Psychomotor Development. Developmental
Psychobiology. 2015;57:908-920.
132. Goyen TA, Lui K. Longitudinal motor development of "apparently normal" high-risk
infants at 18 months, 3 and 5 years. Early Human Development. 2002;70:103-115.
133. Gray PH, O’Callaghan MJ, Harvey JM, Burke CJ, Payton DJ. Placental pathology and
neurodevelopment of the infant with intrauterine growth restriction. Developmental
Medicine & Child Neurology. 1999;41:16-20.
196
134. Handal M, Skurtveit S, Furu K, Hernandez-Diaz S, Skovlud E, Nystad W, Selmer R.
Motor development in children prenatally exposed to selective serotonin reuptake
inhibitors: a large population-based pregnancy cohort study. BJOG: An International
Journal of Obstetrics and Gynaecology. 2016;123:1908-1917.
135. Hanley GE, Bartin U, Oberlander TF. Infant development outcomes following prenatal
exposure to antidepressants, and maternal depressed mood and positive affect. Early
Human Development. 2013;89:519-524.
136. Hanson H, Jawad AF, Ryan T, Silver J. Factors Influencing Gross Motor Development in
Young Children in an Urban Child Welfare System. Pediatric Physical Therapy.
2011;23:335-346.
137. Keim SA, Daniels JL, Dole N, Herring AH, Siega-Riz AM, Scheidt PC. A prospective
study of maternal anxiety, perceived stress, and depressive symptoms in relation to infant
cognitive development. Early Human Development. 2011;87:373-380.
138. Kelly Y, Sacker A, Schoon I, Nazroo J. Ethnic differences in achievement of
developmental milestones by 9 months of age: the Millennium Cohort Study.
Developmental Medicine & Child Neurology. 2006;48:825-830.
139. Koutra K, Chatzi L, Bagkeris M, Vassilaki M, Bitsios P, Kogevinas M. Antenatal and
postnatal maternal mental health as determinants of infant neurodevelopment at 18 months
197
of age in a mother-child cohort (Rhea Study) in Crete, Greece. Social Psychiatry
Psychiatrics Epidemiology. 2013;48:1335-1345.
140. Koutra K, Chatzi L, Roumeliotaki T, Vassilaki M, Giannakopoulou E, Batsos C, Koutis
A, Kogevinas M. Socio-demographic determinants of infant neurodevelopment at 18
months of age:Mother-Child Cohort (Rhea Study) in Crete, Greece. Infant Behavior &
Development. 2012;35:48-59.
141. Laucht M, Esser G, Schmidt M. Developmental Outcome of Infants Born with Biological
and Psychosocial Risks. Journal of Child Psychology and Psychiatry. 1997;38(7):843-853.
142. Leventakou V, Roiumeliotaki T, Koutra K, Vassilaki M, Mantzouranis E, Bitsios P,
Kogevinas M Chatzi L. Breastfeeding duration and cognitive, language and motor
development at 18 months of age: Rhea mother-child cohort in Crete, Greece. Journal of
Epidemiology and Community Health. 2015;69:232-239.
143. Long SH, Eldridge BJ, Harris SR, Cheung MH. Motor skills of 5-year-old children who
underwent early cardiac surgery. Cardiology in the Young. 2016;26:650-657.
144. Majnemer A, Barr, RG. Association Between Sleep Position and Early Motor
Development. The Journal of Pediatrics. 2006;149:623-629.
198
145. Majnemer A, Barr, RG. Influence of supine sleep positioning on early motor milestone
acquisition. Development Medicine & Child Neurology. 2005;47:370-376.
146. McGrath MM, Sullivan MC. Medical and Ecological Factors in Estimating Motor
Outcomes of Preschool Children. Research in Nursing & Health. 1999;22:155-167.
147. McDonald J, Webster V, Knight J, Comino E. The Gudaga Study: Development in 3-
year-old urban Aboriginal children. Journal of Paediatrics and Child Health. 2014;50:100-
106.
148. Michalowicz BS, Hodges JS, Lussky RC, Bada H, Rawson T, Buttross LS, Chiriboga C,
DiAngelis J, Novak MJ, Buchanan W, Mitchell DA, Pappanou PN. Maternal Periodontitis
Treatment and Child Neurodevelopment at 24 to 28 Months of Age. Pediatrics.
2011;127:e1212-e1220.
149. Nervik D, Martin K, Rundquist P, Cleland J. The relationship Between Body Mass Index
and Gross Motor Development in Children Aged 3 to 5 Years. Pediatric Physical Therapy.
2011;23:144-148.
150. Oddy WH, Robinson M, Kendall GE, Li J, Zubrick SR, Stanley FJ. Breastfeeding and
early child development: a prospective cohort study. Acta Paediatrica. 2011;100:992-999.
199
151. Piteo AM, Yelland LN, Makrides M. Does maternal depression predict developmental
outcome in 18 months old infants? Early Human Development. 2012;88:651-655.
152. Richardson GA, Day NL, Goldschmidt L. Prenatal Alcohol, Marijuana, and Tobacco
Use: Infant Mental and Motor Development. Neurotoxicology and Teratology.
1995;17(4):479-487.
153. Saraiva L, Rodrigues LP, Cordovil R, Barreiros J. Influence of age, sex and somatic
variables on the motor performance of pre-school children. Annals of Human Biology.
2013;40(5):444-450.
154. Smith LM, LaGrasse LL, Derauf C, Newman E, Shah R, Haning W, Arria A, Huestis M,
Strauss A, Della Grotta S, Dansereau LM, Lin H, Lester BM. Motor and cognitive
outcomes through three years of age in children exposed to prenatal methamphetamine.
Neurotoxicology and Teratology. 2011;33:176-184.
155. Sommerfelt K, Ellertsen B, Markestad T. Low birthweight and neuromotor development:
a population based, controlled study. Acta Paediatrica. 1996;85:604-610.
156. Tirosh E, Jaffe M, Marmur R, Taub Y, Rosenberg Z. Prognosis of motor development
and joint hypermobility. Archives of Disease in Childhood. 1999;66:931-933.
200
157. Torsvik IK, Ueland PM, Markestad T, Midttun O, Monsen AB. Motor development
related to duration of exclusive breastfeeding, B vitamin status and B12 supplementation in
infants with a birth weight between 2000-3000 g, results from a randomized intervention
trial. BMC Pediatrics. 2015;15:218.
158. Tsuchiya KJ, Tsutsumi H, Matsumoto K, Takei N, Narumiya M, Honda M, Thanseem I,
Anitha A, Suzuki K, Matsuzaki H, Iwata Y, Nakamura K, Mori N. Seasonal Variations of
Neuromotor Development By 14 Months of Age: Hamamatsu Birth Cohort for Mothers
and Children (HBC Study). PLOS ONE. 2012;7(12):e52057-e512057.
159. Veiby G, Engelsen BA, Gilhus NE. Early Child Development and Exposure to
Antiepileptic Drugs Prenatally and Through Breastfeeding - A Prospective Cohort Study
on Children of Women With Epilepsy. JAMA Neurol. 2013;70(11):1367-1374.
160. Velikos K, Soubasi V, Michalettou I, Sarafidis K, Nakas C, Papadopoulou V, Zafeiriou
D, Drossou V. Bayley-III scales at 12 months of corrected age in preterm infants: Patterns
of developmental performance and correlations to environmental and biological influences.
Research in Developmental Disabilities. 2015;45(46):110-119.
161. Wylie A, Sundaran R, Kus C, Ghassabian A, Yeung EH. Materal Prepregnancy Obesity
and Achievement of Infant Motor Developmental Milestones in the Upstate KIDS Study.
Obesity Journal. 2015;23(4):907-912.
201
162. Yeung EH, Sundaram R, Bell EM, Druschel C, Kus C, Ghassabian A, Bello S, Xie Y,
Louis MB. Examining Infertility Treatment and Early Childhood Development in the
Upstate KIDS Study. JAMA Pediatrics. 2016;170(3):251-258.
163. Tough SC, McDonald SW, Collisson BA, Graham SA, Kehler H, Kingston D, Benzies K.
Cohort profile: the All Our Families cohort (AOF). Submitted to International Journal of
Epidemiology. November 2016. (in revisions)
164. Squires J, Twombly E, Bricker D, Potter L. ASQ-3™ User's Guide. Paul H. Brookes
Publishing Co., Baltimore, MD. 2009.
165. Ballantyne M, Benzies KM, McDonald S, Magill-Evans J, Tough S. Risk of
developmental delay: Comparison of late preterm and full term Canadian infants at age 12
months. Early Human Development. 2016;101:27-32.
166. Blauw-Hospers CH, Hadders-Algra M. A systematic review of the effects of early
intervention on motor development. Developmental Medicine & Child Neurology.
2005;47:421–432.
167. Williams R, Clinton J, Canadian Paediatric Society. Getting it right at 18 months: In
support of an enhanced well-baby visit. Paediatrics and Child Health.2011;16(10):647-50.
202
168. R Core Team (2016). R: A language and environment for statistical computing. R
Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/.
169. Terry Therneau, Beth Atkinson and Brian Ripley (2015). rpart: Recursive Partitioning
and Regression Trees. R package version 4.1-10.https://CRAN.R-
project.org/package=rpart
170. Katz MH. Multivariable Analysis: A Practical Guide for Clinicians. 2nd ed. New York:
Cambridge University Press, 2006.
171. Peduzzi P, Concato J, Kemper E, Holford TR, Feinstein AR. A simulation study of the
number of events per variable in logistic regression analysis. Journal of Clinical
Epidemiology. 1996;49:1373-1379.
172. Bursac Z, Gauss CH, Williams DK, Hosmer DW. Purposeful selection of variables in
logistic regression. Source Code for Biology and Medicine. 2008;3(17): 1-8.
173. Hosmer DW, Lemeshow S. A goodness-of-fit test for the multiple logistic regression
model. Communications in Statistics A. 1980;10:1043-1069.
174. StataCorp. 2015. Stata Statistical Software: Release 14. College Station, TX: StataCorp
LP.
203
175. To T, Guttman A, Dick PT, Rosenfield JD,.Parkin PC, Cao H, Vydykhan TN, Tassouji
M, Harris JK. What factors are associated with poor developmental attainment in young
Canadian children? Canadian Journal of Public Health. 2004;95(4):258-263.
176. To T, Guttmann A, Dick PT, Rosenfield JD, Parkin PC, Tassoudji M, Vydykhan TN, Cao
H, Harris JK. Risk Markers for Poor Developmental Attainment in Young Children.
Archives of Pediatric and Adolescent Medicine. 2004;158:643-649.
177. Saccani R, Valentini NC, Pereira KR, Muller AB, Gabbard C.Associations of biological
factors and affordances in the home with infant motor development. Pediatrics
International. 2013;55(2):197-203.
178. Blake J. Family Size and Achievement. University of California Press; 1989:412.
179. Gracie SK, Lyon AW, Kehler HL, Pennell CE, Dolan SM, McNeil DA, Siever JE,
McDonald SW, Bocking AD, Lye SJ, Hegadoren KM, Olson DM, Tough SC. All Our
Babies Cohort Study: recruitment of a cohort to predict women at risk of preterm birth
through the examination of gene expression profiles and the environment. BMC Pregnancy
and Childbirth. 2010;10(87):1-9.
180. Schonhaut L, Armijo I, Schönstedt M, Alvarez J, Cordero M. Validity of the Ages and
Stages Questionnaires in Term and Preterm Infants. Pediatrics. 2013;131(5):e1468-1474.
204
181. Little RE, Anderson KW, Ervin CH, Worthington-Roberts B, Clarren SK. Maternal
Alcohol Use During Breast-Feeding and Infant Mental and Motor Development at One
Year. The New England Journal of Medicine. 1989;321(7):425-430.
182. Burns Y, O'Callaghan M, McDonell B, Rogers Y. Movement and motor development in
ELBW infants at 1 year is related to cognitive and motor abilities at 4 years. Early Human
Development. 2004;80(1):19-29.
183. Visscher C, Houwen S, Scherder EJA, Moolenaar B, Hartman E. Motor Profile of
Children with Developmental Speech and Language Disorders. Pediatrics.
2007;120(1):e158-163.
184. Webster RI, Erdos C, Evans K, Majnemer A, Kehavia E, Thordardottir E, Evans A,
Shevell MI. The clinical spectrum of developmental language impairment in school-aged
children: language, cognitive, and motor findings. Pediatrics. 2006;118(5):e1541-1549.
185. Downey DB. Number of siblings and intellectual development: The resource dilution
explanation. American Psychologist. 2001;56(6–7):497–504.
186. Hall JG. Twinning. Lancet. 2003. 362(9385):735-743.
187. Touwen B. Neurological development in infancy. London:William Heinemann Medical
Books.
205
188. Davis BE, Moon RY, Sachs HC, Ottolini MC. Effects of sleep position on infant motor
development. Pediatrics. 1998;102(5):1135-40.
189. Bhandari A. Self-reported utilization of health care services: Improving measurement and
accuracy. Medical Care Research and Review. 2006;63(2):217-35.
190. Streiner DL. Breaking Up is Hard to Do: The Heartbreak of Dichotomizing Continuous
Data. Research Methods in Psychiatry. 47(3):262-265.
191. Spielberger, C. D. (1983). Manual for the State–Trait Anxiety Inventory (Form Y). Palo
Alto, CA: Mind Garden.
192. Shields M, Tremblay S. The Health of Canada’s Communities. Supplement to Health
Reports. 2002;13:1-24.
193. William R, Clinton J, Canadian Paediatric Society Early Years Task Force. Getting it
right at 18 months: In support of an enhanced well-baby visit. Paediatrics & Child Health.
2011;16(10):647-650.
206
194. McDonald SW, Hicks M, Rasmussen C, Nagulesapillai T, Cook J, Tough SC.
Characteristics of Women Who Consume Alcohol Before and After Pregnancy
Recognition in a Canadian Sample: A Prospective Cohort Study. Alcoholism: Clinical and
Experimental Research. 2014;38(12):3008-3016.
207
APPENDIX A: DESCRIPTIVE STATISTICS FOR THE POTENTIAL SOCIODEMOGRAPHIC, MATERNAL HEALTH,
BIRTH OUTCOME, CHILD HEALTH, AND ENVIRONMENTAL FACTORS
Gross Motor Delays at 24 months
***Missing n=36***
____________________________________________________
Typical
Development
n (row/column%)
Delayed
Development
n (row/column%)
Missing p-value
Fine Motor Delays at 24 months
***Missing n=45***
________________________________________________
Typical
Development
n (row/column%)
Delayed
Development
n (row/column%)
Missing p-value
Socio- Demographics Factors
Marital Status at Q1?
Married/Common-law
Other
1286 (86.60/95.68)
58 (87.88/4.32)
199 (13.40/96.14)
8 (12.12/3.86)
11
0.765
1308 (88.56/95.68)
59 (90.77/4.32)
169 (11.44/96.57)
6 (9.23/3.43)
11
0.582
Marital Status at Q4?
Married/Common-law
Other
1096 (86.98/98.03)
22 (78.57/1.97)
164 (13.02/96.47)
6 (21.43/3.53)
279
0.193
1121 (89.25/97.82)
25 (89.29/2.18)
135 (10.75/97.83)
3 (10.71/2.17)
279
0.995
Highest level of education
completed?
High School
Some or completed post-
secondary
106 (82.81/7.89)
1238 (87.06/92.11)
22 (17.19/10.68)
184 (12.94/89.32)
12
0.175
110 (86.61/8.05)
1257 (88.90/91.95)
17 (13.39/9.77)
157 (11.10/90.23)
12
0.436
Were you born in Canada?
Yes
No
1092 (87.29/81.25)
252 (84.00/18.75)
159 (12.71/76.81)
48 (16.00/23.19)
11
0.132
1116 (89.93/81.64)
251 (83.39/18.36)
125 (10.07/71.43)
50 (16.61/28.57)
11
0.001
How many years have you
lived in Canada?
>60 months
<60 months
1229 (86.92/91.65)
112 (84.85/8.35)
185 (13.08/90.24)
20 (15.15/9.76)
16
0.086
1253 (89.18/92.00)
109 (82.58/8.00)
152 (10.82/86.86)
23 (17.42/13.14)
16
0.022
208
How would you describe
your ethnic background?
Other
White/Caucasian
231 (84.62/17.19)
1113 (87.16/82.81)
42 (15.38/20.39)
164 (12.84/79.61)
12
0.261
221 (80.66/16.17)
1146 (90.45/83.83)
53 (19.34/30.46)
121 (9.55/69.54)
12
<0.001
Maternal age at Q1?
<35 years of age
>35 years of age
1038 (86.14/79.00)
276 (87.90/21.00)
167 (13.86/81.46)
38 (12.10/18.54)
43
0.417
1060 (88.55/79.28)
277 (88.50/20.72)
137 (11.45/79.19)
36 (11.50/20.81)
43
0.978
Paternal age at Q1?
<35 years of age
>35 years of age
817 (86.27/63.48)
470 (86.56/36.52)
130 (13.73/64.04)
73 (13.44/35.96)
74
0.878
846 (89.71/64.33)
469 (87.01/35.67)
97 (10.29/58.08)
70 (12.99/41.92)
74
0.114
Household income at Q1?
<$80,000
>$80,000
351 (85.40/27.21)
939 (86.78/72.79)
60 (14.60/29.56)
143 (13.22/70.44)
71
0.486
349 (85.54/26.64)
961 (89.31/73.36)
59 (14.46/33.91)
115 (10.69/66.09)
71
0.044
Household income at Q4?
<$80,000
>$80,000
340 (85.21/30.80)
764 (87.31/69.20)
59 (14.79/34.71)
111 (12.69/65.29)
293
0.306
349 (87.69/30.80)
784 (89.91/69.20)
49 (12.31/35.77)
88 (10.09/64.23)
293
0.237
Do you receive income support
from the government?
Yes
No
68 (88.31/5.07)
1273 (86.60/94.93)
9 (11.69/4.37)
197 (13.40/95.63)
15
0.666
66 (88.00/4.84)
1297 (88.65/95.16)
9 (12.00/5.14)
166 (11.35/94.86)
15
0.862
Maternal employment at Q2?
Working
Not Working
836 (87.91/62.90)
493 (84.85/37.10)
115 (12.09/56.65)
88 (15.15/43.35)
30
0.087
845 (89.14/62.41)
509 (88.52/37.59)
103 (10.86/60.95)
66 (11.48/39.05)
30
0.712
Maternal employment at Q3?
Maternity leave/stay-at-home
mom/other
Working a job outside the
home/Student
1236 (86.31/94.21)
76 (91.57/5.79)
196 (13.69/96.55)
7 (8.43/3.45)
46
0.172
1262 (88.62/94.46)
74 (89.16/5.54)
162 (11.38/94.74)
9 (10.84/5.26)
46
0.882
Maternal employment at Q5?
Work/study
Not working/studying
971 (86.54/72.30)
372 (86.92/27.70)
151 (13.46/72.95)
56 (13.08/27.05)
11
0.847
991 (88.80/72.55)
375 (88.03/27.45)
125 (11.20/71.02)
51 (11.97/28.98)
11
0.670
209
Type of housing at Q1
House/townhouse
Apartment, condo,
duplex/fourplex, other
1089 (86.50/81.09)
254 (87.29/18.91)
170 (13.50/82.13)
37 (12.71/17.87)
12
0.722
1105 (88.33/80.89)
261 (90.00/19.11)
146 (11.67/83.43)
29 (10.00/16.57)
12
0.419
Type of housing at Q3
House/townhouse
Apartment, condo,
duplex/fourplex, other
1151 (86.93/87.80)
160 (84.21/12.20)
173 (13.07/85.22)
30 (15.79/14.78)
47
0.303
1166 (88.67/87.41)
168 (87.96/12.59)
149 (11.33/86.63)
23 (12.04/13.37)
47
0.773
Do you have a partner at Q3?
Yes
No
1302 (86.68/99.24)
10 (76.92/0.76)
200 (13.32/98.52)
3 (23.08/1.48)
46
0.304
1324 (88.62/99.18)
11 (84.62/0.82)
170 (11.38/98.84)
2 (15.38/1.16)
46
0.651
Do you have a partner at Q4?
Yes
No
1105 (86.87/98.75)
14 (82.35/1.25)
167 (13.13/98.24)
3 (17.65/1.76)
278
0.584
1133 (89.35/98.78)
14 (82.35/1.22)
135 (10.65/97.83)
3 (17.65/2.17)
278
0.354
Child’s sex (biological) (Q3)
Boy
Girl
690 (87.67/52.55)
623 (85.58/47.45)
97 (12.33/48.02)
105 (14.42/51.98)
46
0.230
684 (87.36/51.20)
652 (90.06/48.80)
99 (12.64/57.89)
72 (9.94/42.11)
46
0.099
Maternal Physical Health
Rating of overall physical
health at Q1?
Excellent/Very Good/Good
Fair/Poor
1224 (86.93/91.14)
119 (83.80/8.86)
184 (13.07/88.89)
23 (16.20/11.11)
12
0.296
1249 (89.09/91.43)
117 (84.17/8.57)
153 (10.91/87.43)
22 (15.83/12.57)
12
0.082
Rating of overall physical
health at Q2?
Excellent/Very Good/Good
Fair/Poor
1224 (87.12/92.03)
106 (82.17/7.97)
181 (12.88/88.73)
23 (17.83/11.27)
28
0.113
1247 (89.20/92.03)
108 (85.04/7.97)
151 (10.80/88.82)
19 (14.96/11.18)
28
0.154
Rating of overall physical
health at Q3?
Excellent/Very Good/Good
Fair/Poor
1161 (86.45/88.36)
153 (87.93/11.64)
182 (13.55/89.66)
21 (12.07/10.34)
45
0.589
1191 (89.15/89.08)
146 (84.39/10.92)
145 (10.85/84.30)
27 (15.61/15.70)
45
0.064
210
Rating of overall physical
health at Q4?
Excellent/Very Good/Good
Fair/Poor
1043 (86.70/93.38)
74 (88.10/6.62)
160 (13.30/94.12)
10 (11.90/5.88)
280
0.715
1073 (89.49/93.71)
72 (85.71/6.29)
126 (10.51/91.30)
12 (14.29/8.70)
280
0.280
How often do you exercise
15-30 mins per day during
pregnancy at Q1?
0-2 per week
3+ per week
649 (86.65/48.36)
693 (86.62/51.64)
100 (13.35/48.31)
107 (13.38/51.69)
13
0.989
653 (87.53/47.80)
713 (89.80/52.20)
93 (12.47/53.45)
81 (10.20/46.55)
13
0.161
How often do you exercise
15-30 mins per day during
pregnancy at Q2?
0-2 per week
3+ per week
741 (86.77/55.76)
588 (86.60/44.24)
113 (13.23/55.39)
91 (13.40/44.61)
29
0.922
748 (88.21/55.20)
607 (89.79/44.80)
100 (11.79/59.17)
69 (10.21/40.83)
29
0.327
During this pregnancy, have
you taken any prescription
medicine?
Yes
No
573 (87.75/43.08)
757 (86.02/56.92)
80 (12.25/39.41)
123 (13.98/60.59)
29
0.324
580 (89.51/42.80)
775 (88.47/57.20)
68 (10.49/40.24)
101 (11.53/59.76)
29
0.524
Since becoming pregnant,
have you smoked cigarettes?
Yes
No
142 (87.65/10.67)
1189 (86.60/89.33)
20 (12.35/9.80)
184 (13.40/90.20)
27
0.708
148 (92.50/10.91)
1208 (88.43/89.09)
12 (7.50/7.06)
158 (11.57/92.94)
27
0.122
Since giving birth, have you
smoked cigarettes?
Yes
No
85 (89.47/6.48)
1227 (86.47/93.52)
10 (10.53/4.95)
192 (13.53/95.05)
47
0.404
84 (88.42/6.30)
1250 (8.59/93.70)
11 (11.58/6.40)
161 (11.41/93.60)
47
0.960
Since your baby was 4
months old, have you
smoked cigarettes?
Yes
No
88 (91.67/7.88)
1029 (86.40/92.12)
8 (8.33/4.71)
162 (13.60/95.29)
280
0.142
87 (91.58/7.60)
1058 (89.06/92.40)
8 (8.42/5.80)
130 (10.94/94.20)
280
0.445
211
Since becoming pregnant,
did you drink any alcohol?
Yes
No
642 (86.87/48.23)
689 (86.56/51.77)
97 (13.13/47.55)
107 (13.44/52.45)
27
0.855
664 (90.59/48.93)
693 (87.28/51.07)
69 (9.41/40.59)
101 (12.72/59.41)
27
0.040
Since the birth of your
baby, did you drink any
alcohol?
Yes
No
887 (87.30/67.61)
425 (85.34/32.39)
129 (12.70/63.86)
73 (14.66/36.14)
47
0.292
902 (89.48/67.62)
432 (86.75/32.38)
106 (10.52/61.63)
66 (13.25/38.37)
47
0.116
Since your baby was 4
months old, have you
consumed any alcoholic
drink?
Yes
No
834 (87.51/74.60)
284 (84.78/25.40)
119 (12.49/70.00)
51 (15.22/30.00)
279
0.203
863 (90.84/75.24)
284 (84.78/24.76)
87 (9.16/63.04)
51 (15.22/36.96)
279
0.002
Since becoming pregnant,
have you used street drugs?
Yes
No
48 (85.71/3.61)
1282 (86.74/96.39)
8 (14.29/3.92)
196 (13.26/96.08)
28
0.825
48 (87.27/3.54)
1307 (88.91/96.46)
7 (12.73/4.12)
163 (11.09/95.88)
28
0.705
In the past month, have you
used street drugs?
Yes
No
19 (82.61/1.45)
1290 (86.69/98.55)
4 (17.39/1.98)
198 (13.31/98.02)
50
0.568
19 (82.61/1.43)
1313 (88.72/98.57)
4 (17.39/2.34)
167 (11.28/97.66)
50
0.360
Since your baby was 4
months old, have you used
street drugs?
Yes
No
19 (70.37/1.70)
1099 (87.22/98.30)
8 (29.63/4.73)
161 (12.78/95.27)
280
0.010
22 (81.48/1.92)
1124 (89.49/98.08)
5 (18.52/3.65)
132 (10.51/96.35)
280
0.182
Maternal Mental Health
Feelings about pregnancy?
Happy
Unhappy/Not sure
1180 (86.26/87.86)
163 (89.56/12.14)
188 (13.74/90.82)
19 (10.44/9.18)
13
0.218
1212 (88.86/88.66)
155 (87.57/11.34)
152 (11.14/87.36)
22 (12.43/12.64)
13
0.611
212
Are you happy to be
pregnant?
Happy
Unhappy/Not sure
1274 (86.84/95.79)
56 (83.58/4.21)
193 (13.16/94.61)
11 (16.42/5.39)
28
0.442
1296 (88.77/59
59 (90.77/4.35)
164 (11.23/96.47)
6 (9.23/3.53)
28
0.616
Rate emotional health at Q1
Excellent/Very good/Good
Fair/Poor
1253 (87.20/93.23)
91 (80.53/6.77)
184 (12.80/89.32)
22 (19.47/10.68)
12
0.044
1272 (88.95/93.12)
94 (84.68/6.88)
158 (11.05/90.29)
17 (15.32/9.71)
12
0.172
Rate emotional health at Q2
Excellent/Very good/Good
Fair/Poor
1258 (87.12/94.59)
72 (80.00/5.41)
186 (12.88/91.18)
18 (20.00/8.82)
28
0.054
1276 (88.92/94.17)
79 (87.78/5.83)
159 (11.08/93.53)
11 (12.22/6.47)
28
0.738
Rate emotional health at Q3
Excellent/Very good/Good
Fair/Poor
1226 (86.77/93.30)
88 (84.62/6.70)
187 (13.23/92.12)
16 (15.38/7.88)
44
0.534
1254 (89.19/93.79)
83 (80.58/6.21)
152 (10.81/88.37)
20 (19.42/11.63)
44
0.008
Rate emotional health at Q4
Excellent/Very good/Good
Fair/Poor
1035 (86.97/92.58)
83 (84.69/7.42)
155 (13.03/91.18)
15 (15.31/8.82)
279
0.521
1063 (89.55/92.76)
83 (85.57/7.24)
124 (10.45/89.86)
14 (14.43/10.14)
279
0.223
Anxiety at Q1
No (<40)
Yes(>40)
1134 (86.83/86.17)
182 (85.05/13.83)
172 (13.17/84.31)
32 (14.95/15.69)
43
0.478
1160 (89.09/86.44)
182 (86.67/13.56)
142 (10.91/83.53)
28 (13.33/16.47)
43
0.302
Anxiety at Q2
No (<40)
Yes(>40)
1064 (86.50/81.72)
238 (87.18/18.28)
166 (13.50/82.59)
35 (12.82/17.41)
6
0.767
1098 (89.56/82.74)
229 (85.13/17.26)
128 (10.44/76.19)
40 (14.87/23.81)
62
0.037
Anxiety at Q3
No (<40)
Yes(>40)
1081 (86.48/86.20)
173 (87.37/13.80)
169 (13.52/87.11)
25 (12.63/12.89)
116
0.732
1110 (89.09/86.85)
168 (86.60/13.15)
136 (10.91/83.95)
26 (13.40/16.05)
62
0.308
Anxiety at Q4
No (<40)
Yes(>40)
910 (87.16/83.79)
176 (86.27/16.21)
134 (12.84/82.72)
28 (13.73/17.28)
323
0.729
940 (90.21/84.53)
172 (85.15/15.47)
102 (9.79/77.27)
30 (14.85/22.73)
323
0.032
213
Maternal Separation
Anxiety Scale
Low symptoms of separation
anxiety
High symptoms of separation
anxiety
937 (87.33/84.80)
168 (84.85/15.20)
136 (12.67/81.93)
30 (15.15/18.07)
296
0.342
957 (89.52/84.77)
172 (86.87/15.23)
112 (10.48/81.16)
26 (13.13/18.84)
296
0.271
Social Support at Q1 (MOS)
Adequate (<70)
Inadequate (>70)
1188 (87.29/88.92)
148 (82.22/11.08)
173 (12.71/84.39)
32 (17.78/15.61)
22
0.060
1216 (89.81/89.54)
142 (79.78/10.46)
138 (10.19/79.31)
36 (20.22/20.69)
22
<0.001
Social Support at Q2 (MOS)
Adequate (<70)
Inadequate (>70)
1149 (87.51/86.98)
172 (81.52/13.02)
164 (12.49/80.79)
39 (18.48/19.21)
38
0.017
1172 (89.67/87.07)
174 (83.65/12.93)
135 (10.33/79.88)
34 (16.35/20.12)
38
0.010
Social Support at Q3 (MOS)
Adequate (<70)
Inadequate (>70)
1120 (87.30/87.02)
167 (81.07/12.98)
163 (12.70/80.69)
39 (18.93/19.31)
74
0.015
1148 (89.76/87.50)
164 (81.19/12.50)
131 (10.24/77.51)
38 (18.81/22.49)
74
<0.001
Social Support at Q4
(NLSCY)
Moderate or high support
(>17)
Low support (<17)
909 (87.40/81.52)
206 (84.08/18.48)
131 (12.60/77.06)
39 (15.92/22.94)
283
0.167
937 (90.36/81.98)
206 (84.43/18.02)
100 (9.64/72.46)
38 (15.57/27.54)
283
0.007
Perceived Stress at Q1
Low symptoms of stress
(<20)
High symptoms of stress
(>20)
1145 (86.68/85.51)
194 (86.22/14.49)
176 (13.32/85.02)
31 (13.78/14.98)
17
0.853
1170 (89.04/85.90)
192 (86.10/14.10)
144 (10.96/82.29)
31 (13.90/17.71)
17
0.201
Perceived Stress at Q2
Low symptoms of stress
(<19)
High symptoms of stress
(>19)
1090 (86.99/82.76)
227 (85.34/17.24)
163 (13.01/80.69)
39 (14.66/19.31)
43
0.471
1117 (89.50/83.30)
224 (85.50/16.70)
131 (10.50/77.51)
38 (14.50/22.49)
43
0.061
214
Perceived Stress at Q3
Low symptoms of stress
(<19)
High symptoms of stress
(>19)
1115 (87.25/86.57)
173 (82.38/13.43)
163 (12.75/81.50)
37 (17.62/18.50)
75
0.055
1141 (89.49/87.10)
169 (82.44/12.90)
134 (10.51/78.82)
36 (17.56/21.18)
75
0.003
Perceived Stress at Q4
Low symptoms of stress
(<19)
High symptoms of stress
(>19)
876 (87.78/80.37)
214 (82.95/19.63)
122 (12.22/73.49)
44 (17.05/26.51)
312
0.041
898 (90.16/80.47)
218 (85.16/19.53)
98 (9.84/72.06)
38 (14.84/27.94)
312
0.022
Depression at Q1
No (<10)
Yes (>10)
1140 (87.16/84.88)
203 (84.23/15.12)
168 (12.84/81.55)
38 (15.77/18.45)
13
0.219
1163 (89.32/85.20)
202 (84.87/14.80)
139 (10.68/79.43)
36 (15.14/20.57)
13
0.047
Depression at Q2
No (<10)
Yes (>10)
1140 (87.22/85.78)
189 (83.63/14.22)
167 (12.78/81.86)
37 (16.37/18.14)
29
0.142
1163 (89.46/85.83)
192 (85.71/14.17)
137 (10.54/81.07)
32 (14.29/18.93)
29
0.099
Depression at Q3
No (<10)
Yes (>10)
1171 (87.19/89.53)
137 (81.55/10.47)
172 (12.81/84.73)
31 (18.45/15.27)
50
0.043
1198 (89.54/90.01)
133 (80.61/9.99)
140 (10.46/81.40)
32 (19.39/18.60)
50
0.001
Depression at Q4
No (<10)
Yes (>10)
975 (86.67/87.52)
139 (88.54/12.48)
150 (13.33/89.29)
18 (11.46/10.71)
285
0.516
1004 (89.40/88.07)
136 (87.74/11.93)
119 (10.60/86.23)
19 (12.26/13.77)
285
0.532
Did you experience
postpartum depression
since your most recent
pregnancy?
Yes
No
258 (86.00/23.06)
861 (87.06/76.94)
42 (14.00/24.71)
128 (12.94/75.29)
278
0.635
266 (89.26/23.19)
881 (89.26/76.81)
32 (10.74/23.19)
106 (10.74/76.81)
278
0.999
Optimism (Q2)
High optimism (>15)
Low optimism (<15)
1097 (86.86/83.30)
220 (85.60/16.70)
166 (13.14/81.77)
37 (14.40/18.23)
42
0.590
1120 (89.17/83.33)
224 (87.84/16.67)
136 (10.83/81.44)
31 (12.16/18.56)
42
0.537
215
Parenting Morale Index (Q3)
Moderate to high parenting
morale (>33)
Low parenting morale (<33)
1040 (87.25/83.13)
211 (85.08/16.87)
152 (12.75/80.42)
37 (14.92/19.58)
123
0.358
1065 (89.42/83.59)
209 (86.59/16.41)
126 (10.58/79.75)
32 (13.28/20.25)
123
0.223
Pregnancy and Birth Outcome Factors
Term status
<37 weeks gestation
>37 weeks gestation
188 (85.45/14.41)
1117 (86.93/85.59)
32 (14.55/16.00)
168 (13.07/84.00)
56
0.552
188 (86.24/14.17)
1139 (89.05/85.83)
30 (13.76/17.65)
140 (10.95/82.35)
56
0.226
Term status EHR
<30 weeks gestation
>30 weeks gestation
6 (75.00/0.05)
1203 (87.17/99.50)
2 (25.00/1.12)
177 (12.83/98.88)
178
0.306
8 (100.00/0.66)
1212 (88.40/99.34)
0 (0.00/0.00)
159 (11.60/100.00)
178
0.306
Type of delivery
Vaginal
C-Section
992 (86.71/75.55)
321 (86.29/24.45)
152 (13.29/74.88)
51 (13.71/25.12)
45
0.835
1010 (88.67/75.60)
326 (88.35/24.40)
129 (11.33/75.00)
43 (11.65/25.00)
45
0.863
Number of days baby spent
in hospital after birth?
<3 days
>3 days
1097 (87.27/88.11)
148 (81.32/11.89)
160 (12.73/82.47)
34 (18.68/17.53)
123
0.028
1110 (88.80/87.61)
157 (86.26/12.39)
140 (11.20/84.85)
25 (13.74/15.15)
123
0.317
Antenatal Steroids?
Yes
No
30 (76.92/2.59)
1127 (87.57/97.41)
9 (23.08/5.33)
160 (12.43/94.67)
240
0.050
31 (79.49/2.66)
1133 (88.58/97.34)
8 (20.51/5.19)
146 (11.42/94.81)
240
0.081
Complications during
pregnancy?
No
Yes
1262 (86.26/93.27)
91 (93.81/6.73)
201 (13.74/97.10)
6 (6.19/2.90)
0
0.034
1283 (88.24/93.31)
92 (94.85/6.69)
171 (11.76/97.16)
5 (5.15/2.84)
0
0.047
5-minute Apgar Scores
>7
<7
1193 (87.40/98.92)
13 (65.00/1.08)
172 (12.60/96.09)
7 (35.00/3.91)
181
0.003
1201 (88.57/98.69)
16 (80.00/1.31)
155 (11.43/97.48)
4 (20.00/2.52)
181
0.234
216
NICU admission?
No
Yes
1245 (87.12/92.02)
108 (82.44/7.98)
184 (12.88/88.89)
23 (17.56/11.11)
0
0.131
1266 (89.15/92.07)
109 (83.21/7.93)
154 (10.85/87.50)
22 (16.79/12.50)
0
0.040
Intrauterine Growth
Restrictions
No
Yes
1323 (86.75/97.78)
30 (85.71/2.22)
202 (13.25/97.58)
5 (14.29/2.42)
0
0.858
1344 (88.65/97.75)
31 (88.57/2.25)
172 (11.35/97.73)
4 (11.43/2.27)
0
0.988
Birth weight (Q3)
None low birth weight
(>2500g)
Low birth weight (<2500g)
1174 (86.96/94.75)
65 (77.38/5.25)
176 (13.04/90.26)
19 (22.62/9.74)
128
0.013
1194 (88.91/94.39)
71 (85.54/5.61)
149 (11.09/92.55)
12 (14.46/7.45)
128
0.347
Birth weight (EHR)
None low birth weight
(>2500g)
Low birth weight (<2500g)
1151 (87.46/95.20)
58 (80.56/4.80)
165 (12.54/92.18)
14 (19.44/7.82)
178
0.089
1160 (88.69/95.08)
60 (84.51/4.92)
148 (11.31/93.08)
11 (15.49/6.92)
178
0.283
Small-for-gestational age
Not SGA
SGA
1113 (86.89/90.49)
117 (82.39/9.51)
168 (13.11/87.05)
25 (17.61/12.95)
139
0.138
1129 (88.62/89.96)
126 (89.36/10.04)
145 (11.38/90.62)
15 (10.64/9.38)
139
0.791
Child Health Factors
Baby’s general health
Excellent/Very good/Good
Fair/Poor
1112 (86.81/99.37)
7 (87.50/0.63)
169 (13.19/99.41)
1 (12.50/0.59)
279
0.954
1141 (89.35/99.48)
6 (75.00/0.52)
136 (10.65/98.55)
2 (25.00/1.45)
279
0.191
Has your baby been
diagnosed with any long-
term conditions?
Yes
No
66 (79.52/5.90)
1052( 87.38/94.10)
17 (20.48/10.06)
152 (12.62/89.94)
280
0.040
71 (85.54/6.20)
1074 (89.50/93.80)
12 (14.46/8.70)
126 (10.50/91.30)
280
0.260
217
How was your baby fed in
the last week (~4 months)?
Most, some or no
breastfeeding
Only breastfeeding
485 (87.39/37.83)
797 (85.70/62.17)
70 (12.61/34.48)
133 (14.30/65.52)
77
0.359
483 (87.82/36.90)
826 (89.10/63.10)
67 (12.18/39.88)
101 (10.90/60.12)
77
0.452
Breasftfeeding at 12
months?
No
Yes
976 (87.69/72.14)
377 (84.34/27.86)
137 (12.31.66.18)
70 (15.66/33.82)
0
0.078
974 (88.22/70.84)
401 (89.71/29.16)
130 (11.78/73.86)
46 (10.29/26.14)
0
0.404
Communication
Development
On schedule
Delays
896 (87.76/95.93)
38 (66.67/4.07)
125 (12.24/86.81)
19 (33.33/13.19)
495
<0.001
918 (90.09/95.23)
46 (80.70/4.77)
101 (9.91/90.18)
11 (19.30/9.82)
495
0.024
Problem Solving
Development
On schedule
Delays
789 (88.26/84.75)
142 (78.45/15.25)
105 (11.74/72.92)
39 (21.55/27.08)
498
<0.001
816 (91.48/84.91)
145 (80.11/15.09)
76 (8.52/67.86)
36 (19.89/32.14)
498
<0.001
Personal-social
Development
On schedule
Delays
831 (88.40/89.16)
101 (74.26/10.84)
109 (11.60/75.69)
35 (25.74/24.31)
497
<0.001
855 (91.05/88.88)
107 (79.26/11.12)
84 (8.95/75.00)
28 (20.74/25.00)
497
<0.001
Fine Development
On schedule
Delays
854 (87.14/91.53)
79 (81.44/8.47)
126 (12.86/87.50)
18 (18.56/12.50)
496
0.116
887 (90.70/92.11)
76 (78.35/7.89)
91 (9.30/81.25)
21 (21.65/18.75)
496
<0.001
Communication
Development
On schedule
Delays
759 (90.90/81.35)
174 (71.90/18.65)
76 (9.10/52.78)
68 (28.10/47.22)
496
<0.001
753 (90.50/78.19)
210 (86.42/21.81)
79 (9.50/70.54)
33 (13.58/29.46)
496
0.067
Number of live births
None
1 or more
670 (87.35/78.55)
183 (84.72/21.45)
97 (12.65/74.62)
33 (15.28/25.38)
593
0.313
667 (87.65/77.83)
190 (88.37/22.17)
94 (12.35/78.99)
25 (11.63/21.01)
593
0.774
218
Number of months between
your last child and this
pregnancy
>24 months
<24 months
262 (85.62/37.86)
430 (88.30/62.14)
44 (14.38/43.56)
57 (11.70/56.44)
788
0.271
253 (83.50/36.72)
436 (90.08/63.28)
50 (16.50/51.02)
48 (9.92/48.98)
788
0.006
Is your partner happy
about the pregnancy
Very happy/Happy
No opinion/Unhappy/Very
unhappy
1308 (86.62/97.98)
27 (93.10/2.02)
202 (13.38/99.02)
2 (6.90/0.98)
24
0.308
1331 (88.67/98.16)
25 (86.21/1.84)
170 (11.33/97.70)
4 (13.79/2.30)
24
0.678
Partner smokes?
No
Yes
1149 (86.59/86.00)
187 (88.21/14.00)
178 (13.41/87.68)
25 (11.79/12.32)
24
0.517
1179 (89.25/86.88)
178 (85.17/13.12)
142 (10.75/82.08)
31 (14.83/17.92)
24
0.083
How is smoking handled?
No smoking inside the house
Smoking permitted inside the
house
1306 (86.49/97.75)
30 (93.75/2.25)
204 (13.51/99.03)
2 (6.25/0.97)
20
0.232
1330 (88.55/98.01)
27 (87.10/1.99)
172 (11.45/97.73)
4 (12.90/2.27)
20
0.802
How is smoking handled?
No smoking inside the house
Smoking permitted inside the
house
1292 (86.60/98.33)
22 (91.67/1.67)
200 (13.40/99.01)
2 (8.33/0.99)
47
0.468
1319 (88.82/98.58)
19 (86.36/1.42)
166 (11.18/98.22)
3 (13.64/1.78)
47
0.717
How is smoking handled?
No smoking inside the house
Smoking permitted inside the
house
1260 (86.36/98.28)
22 (88.00/1.72)
199 (13.64/98.51)
3 (12.00/1.49)
77
0.813
1286 (88.57/98.47)
20 (80.00/1.53)
166 (11.43/97.08)
5 (20.00/2.92)
77
0.184
How is smoking handled?
No smoking inside the house
Smoking permitted inside the
house
790 (86.15/71.95)
308 (88.51/28.05)
127 (13.85/76.05)
40 (11.49/23.95)
304
0.269
818 (89.40/72.52)
310 (89.60/27.48)
97 (10.60/72.93)
36 (10.40/27.07)
304
0.919
Did you breastfeed even for
a short time?
Yes
No
1283 (86.40/97.64)
31 (96.88/2.36)
202 (13.60/99.51)
1 (3.12/0.49)
44
0.085
1307 (88.49/97.76)
30 (93.75/2.24)
170 (11.51/98.84)
2 (6.25/1.16)
44
0.354
219
How was the baby fed in the
first week?
Most, some or no
breastfeeding
Only breastfeeding
502 (84.80/39.28)
776 (87.58/60.72)
90 (15.20/45.00)
110 (12.42/55.00)
84
0.125
513 (87.24/39.37)
790 (89.57/60.63)
75 (12.76/44.91)
92 (10.43/55.09)
84
0.169
Community resource
utilization at Q3?
<1
>1
310 (89.86/23.59)
1004 (85.67/76.41)
35 (10.14/17.24)
168 (14.33/82.76)
44
0.045
298 (86.88/22.29)
1039 (89.11/77.71)
45 (13.12/26.16)
127 (10.89/73.84)
44
0.254
Community resource
utilization at Q4?
<1
>1
68 (89.47/6.20)
1028 (86.82/93.80)
8 (10.53/4.88)
156 (13.18/95.12)
307
0.506
62 (81.58/5.51)
1063 (90.08/94.49)
14 (18.42/10.69)
117 (9.92/89.31)
307
0.019
Community resource
utilization at
<1
>1
265 (88.63/19.59)
1088 (86.28/80.41)
34 (11.37/16.43)
173 (13.72/83.57)
0
0.282
252 (84.28/18.33)
1123 (89.70/81.67)
47 (15.72/26.70)
129 (10.30/73.30)
0
0.008
Health Care Utilization at
Q3?
<1
>1
975 (87.76/78.06)
274 (82.28/21.94)
136 (12.24/69.74)
59 (17.72/30.26)
118
0.010
992 (89.77/77.62)
286 (86.40/22.38)
113 (10.23/71.52)
45 (13.60/28.48)
118
0.086
Health Care Utilization at
Q3?
<1
>1
1122 (87.25/82.93)
231 (84.31/17.07)
164 (12.75/79.23)
43 (15.69/20.77)
282
0.193
1133 (88.58/82.40)
242 (88.97/17.60)
146 (11.42/82.95)
30 (11.03/17.05)
282
0.855
Abuse postpartum
No Abuse
Yes Abuse
1233 (87.01/94.63)
70 (78.65/5.37)
184 (12.99/90.64)
19 (21.35/9.36)
55
0.025
1252 (88.79/94.28)
76 (86.36/5.72)
158 (11.21/92.94)
12 (13.64/7.06)
55
0.486
Occasion when food didn’t
last
Never
Often/Sometimes
1254 (86.66/95.43)
60 (86.96/4.57)
193 (13.34/95.54)
9 (13.04/4.46)
45
0.944
1281 (88.96/95.88)
55 (80.88/4.12)
159 (11.04/92.44)
13 (19.12/7.56)
45
0.041
220
Child care arrangement
Partner/Family
members/Friend/Neighbour
Day home/Daycare/Other
741 (86.67/88.11)
100 (88.50/11.89)
114 (13.33/89.76)
13 (11.50/10.24)
604
0.588
754 (88.71/88.71)
96 (86.49/11.29)
96 (11.29/86.49)
15 (13.51/13.51)
604
0.491
Primary type of childcare at
Q4
Mother, relative, nanny
Childcare centre or dayhome
783 (85.57/70.99)
320 (89.39/29.01)
132 (14.43/77.65)
38 (10.61/22.35)
295
0.072
810 (88.91/71.55)
322 (89.94/28.45)
101 (11.09/73.72)
36 (10.06/26.28)
295
0.594
Primary type of childcare at
Q4
Mother, relative, nanny
Childcare centre or dayhome
856 (86.73/63.74)
487 (86.50/36.26)
131 (13.27/63.29)
76 (13.50/36.71)
11
0.900
868 (88.30/63.54)
498 (89.25/36.46)
115 (11.70/65.71)
60 (10.75/34.29)
11
0.574
Order of AOF child
Oldest/only child
Youngest/Middle
642 (86.06/47.49)
710 (87.33/52.51)
104 (13.94/50.24)
103 (12.67/49.76)
1
0.460
672 (90.44/48.91)
702 (86.99/51.09)
71 (9.56/40.34)
105 (13.01/59.66)
1
0.032
Does your child use your
computer?
Yes
No
774 (87.95/60.19)
512 (84.63/39.81)
106 (12.05/53.27)
93 (15.37/46.73)
77
0.064
789 (90.07/60.18)
522 (87.00/39.82)
87 (9.93/52.73)
78 (13.00/47.27)
77
0.066
Time spent watching TV
Less than an hour
An hour or more
737 (86.91/54.47)
616 (86.52/45.53)
111 (13.09/53.62)
96 (13.48/46.38)
0
0.819
756 (89.47/54.98)
619 (87.68/45.02)
89 (10.53/50.57)
87 (12.32/49.43)
0
0.268
Time spent engaging in
physical activity
Less than an hour
An hour or more
17 (77.27/1.26)
1336 (86.87/98.74)
5 (22.73/2.42)
202 (13.13/97.58)
0
0.188
18 (81.82/1.31)
1357 (88.75/98.69)
4 (18.18/2.27)
172 (11.25/97.73)
0
0.309