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The National Ribat University
Faculty of Graduate Studies and Scientific Research
Assessment of Umbilical Artery Blood Flow Indices in Normal
Pregnancy using Ultrasonography
A Thesis Submitted in Partial Fulfillment for the Requirements of
M.Sc. Degree in Diagnostic Medical Ultrasound
By: Samah Mustafa Elawad Mohammed.
Supervisor: Dr. Ahmed Abdelrahim Mohammad Ibrahim
1439 - 2018
I
األيه
قال تعالي:
بسم ميحرلا نمحرلا هللا
متن من تأويل الحاديث ﴿ رب قد آتيتن من المل وعل
هيا ماوات والرض آهت ولي ف ادل والخرة توفن فاطر الس
الحني ﴾ مسلما وآلحقن بلص
صدق هللا العظمي
( 101سوره يوسف الايه رمق)
II
Dedication
“I wish to dedicate this work
To those who gave me to such moment my parents.
To that who gave me happiness my husband.
To those who gave me strength when I was weak my brothers and
sisters.
To those who gave me laughter when I was sad my friends.
To that who helped me my sister daughter.
III
Acknowledgement
Firstly, great thanks to Allah almighty who made all things possible and gave
me power to do such work.
I would like to extend gratitude me to my supervisor Dr. Ahmed Abdelrahim to
his vital encouragement.
I would like to thank the ultrasound unit staffs of the Department of Obstetrics
and Gynecology of Bahri teaching hospital for their kind cooperation and
valuable help
Special thanks to Dr. Zain Elabedeen Mohammad.
.
IV
Abstract
Doppler sonography is a useful tool in assessment of umbilical artery blood
flow during pregnancy.
The aim of this study was to establish a normative data of the umbilical
artery Doppler waveform indices (resistive index pulsitility index and systole to
diastole ratio) in normal fetus using ultrasonography. The problem of study was
that assessment of Doppler indices of umbilical artery become very important
to reduce perinatal mortality and morbidity.
A cross-sectional descriptive study, carried out in Khartoum Bahri hospital in
period from august to December 2017, involved 100 women with singleton
normal pregnancy between 24-40 weeks of gestation, was obtained by color
Doppler duplex ultrasound system (General electric (GE) Mindary DC-
6diagnostic ultrasound system), using Transabdominal curvilinear transducers
of (3.5-5) MHz, after fetal biometry for confirmation of gestational age,
Doppler indices measured during fetal scan. Of three measurements, the mean
average of S/D Ratio, RI and PI recorded in each gestational week, the data as
analyzed by using statistical package for social sciences.
The study found that the values of Doppler indices(S/D ratio, RI and PI)
declined gradually with gestational age. The mean values decreased from 4 to 2,
0.77 to 0.49 and 1.20 to 0.64, respectively. Notably, the Doppler indices were
less than 3, o.99 and 0.66 respectively after 31 weeks of gestation.
In conclusion, Doppler indices are more appropriate tools to assessment blood
flow of umbilical artery .The nomogram of umbilical artery Doppler waveform
indices was constructed and showed the decreasing of Doppler indices with
gestational age.
V
ملخص البحث
انظزي يفذة ف شزانه انجاث فق انصح نألرد انشزا جذ أ إطخخذاو
حمى حذفك انذو ف انشزا انظزي أثاء فخز انحم .
يؤشز يمايت ) انظزي ؤشزاث انشزا يعارت نشاء بااث إل انذراطت ذفج ذ
باطخخذاو انجاث فق يؤشز انبط ظبت االمباض نالبظاط ( ف انج انطبع ,
. حثهج يشكه انذراطت ف حمى يؤشزاث انشزا انظزي انذي أصبح يى جذا انصحت
نخمهم ي االيزاض انفاث لبم انالدة.
,أجزج ف يظخشفى انخزطو بحزي ف انفخز ب دراطت صفت يظخعزظتذ
ف )ج احذ(طبع ان حم ان يحان 011ظج . لذ 7107اغظطض ال دظبز
أطبعا ي انحم حى انحصل عها 21-72ب ي فخز انحم نفخزة انثات انثانثتا
( 5.5-5عبز انبط ) إطخخذاو انجاث فق انصح نألرد انشزا باططت
أخذ بعذ. حشخص( 6-جاس يجاث فق صح دص–. )جزال انكخزن شيغازح
الل يظح خذث لاطاث يؤشزاث انذبهز خأانجت نماص عز انحم انحتانماطاث
يؤشز انبط ظبت ,يؤشز يمايت ) انخططت نظبت تانم لاطاث،انج ي ثالثت
.حمنه انظجهت ف كم أطبع بظاط (إلمباض ناإل
شز يمايت يؤانذو ف انشزا انظزي )يؤشزاث حذفك ظبت لى جذث انذراطت أ
إخفط حخزاجع حذرجا يع عز انحم .( بظاطمباض نإلإليؤشز انبط ظبت ا
انجذز . عهى انخان (1.62انى 0 1.20انى 1.70, 7انى 5.5 )ي يخطط انمى
50عه انخان بعذ 1.66 5,1.00بانذكز أ يؤشزاث حم حذفك انذو كاج ألم ي
أطبعا ي انحم .
بانجاث فق انصحت انظزيحمى حذفك انذو ف انشزا خهصج انذراط ان أ
خطط ن حمى حذفك انذو يؤشزاث خفاضإ أ انذراط أظزث .ياطب جذا طزمت
.انحمعز ساد يع انظزي زاانش
VI
List of Contents
Content page No
ت ا I
Dedication II
Acknowledgement III
Abstract (English) IV
Abstract (Arabic) V
List of contents VI-VII
List of figures VIII
List of table IX
List of abbreviation X
CHAPTER ONE
1.1.Introduction 1
1.2. The problem of study 2
1.3. The objectives of the study 2
CHAPTER TWO
2. Literature review
2.1.Anatomy of umbilical cord 3
2.1.1Development of the umbilical cord 3
2.1.2Umbilical cord insertion 6
2.1.3Sonographic appearance of the umbilical cord 7
2.2.Anatomy and physiology of umbilical artery 8
2.3.Umbilical artery Doppler assessment 9
2.4.Umbilical artery Waveform measured 10
2.5.Doppler Parameters 12
2.6.Benefits of umbilical artery surveillance 13
2.7.Factor affect flow velocity wave form 14
2.8.The Safety of Doppler for the Obstetric Pregnancy 15
2.9. Background studies 16-18
CHAPTER THREE
3.1 Design of study 19
3.2 Sample 19
3.3 Machine 19
3.4 Method of data collection 19
3.5 Study variable 20
3.6 Method of data analysis 20
3.7 Data storage 20
3.8 Data presentation 20
3.9 Ethical consideration 20
VII
CHAPTER FOUR
4. Results 21-24
CHAPTER FIVE
5.1. Discussion 25-27
5.2. Conclusion 28
5.3. Recommendations 29
References 30
Appendices
VIII
List of figures
Figure
No.
Figure name Page
No.
2.1 Beginning of the umbilical cord. 4
2.2 Contents and development of the umbilical cord. 5
2.3 Fetus at ~53 days post-ovulation (21.5 mm crown-rump length) 6
2.4 Cross section of normal umbilical cord 6
2.5 The umbilical cord protects the fetal vessels that connect the
placenta and fetus.
7
2.6 Insertion of umbilical cord into chorionic plate. 7
2.7 Doppler ultrasound of the umbilical cord 8
2.8 Doppler waveforms at 20 and 36 weeks of pregnancy Systole (Sys)
and diastole (D) are identified
8
2.9 Normal umbilical artery Doppler ultrasound in third trimester. 9
2.10 Fluctuations in the waveform of the ductus venous due to fetal
breathing movements during vessel interrogation
10
4.1 linear relationship between the RI and GA-LMP in normal
pregnancies
21
4.2 linear relationship between the RI and FL in normal pregnancies 21
4.3 linear relationship between the PI and GA-LMP in normal
pregnancies
22
4.2 linear relationship between the PI and FL in normal pregnancies 22
4.5 linear relationship between the S/D ratio and GA-LMP in normal
pregnancies
23
4.6 linear relationship between the S/D ratio and FL in normal
pregnancies
23
4.7 variant between GA-FL (Y axis) and GA-LMP (X axis) in normal 24
IX
List of tables
Table
NO Table name Page
NO 4.1 Mean, stander deviation, minimum and maximum of the variables.
22
4.2 correlation between of RI , PI and S\D ratio in relation to GA LMP , GA FL and GA
AVG weeks 24
X
List of abbreviations
EDD
Expected Delivery Date
FL Femur length
GA Gestational Age
LMP Last menstrual period
RI Resistive Index
S/D ratio Systole to Diastole ratio
PI Pulsitility Index
0
Chapter one
Introduction
1
Chapter one
1.1 Introduction
Doppler ultrasonography is none invasive procedure that uses detectable
change in high frequency sound wave (two-twenty megahertz),based on the
Doppler effect to create clear digital image. Doppler ultrasonography has been
used as modality to measure Doppler indices (resistive index, pulsitility index
and systole to diastole ratio) of the umbilical arteries to evaluate the placental
circulation and fetal wellbeing in second and the third trimester. (1)
A basic principle of the umbilical artery waveforms, reflecting the resistance
in fetoplacental circulation, has been used extensively for fetal surveillance,
especially in high-risk pregnancy. The blood velocity waveforms in umbilical
arteries (UAs) show continuous forward flow throughout the cardiac cycle.
Absent of end diastolic flow in umbilical arteries in first trimester and high
vascular impedance detected decreased gradually with advancing pregnancy .it
is attributed to growth of placental unit and increase in the number of
functioning vascular channels. Normal umbilical artery Doppler indices
decrease gradually pulsitility index, resistive index and S/Ratio, (2 to 1), (0.8 to
5) and (5to 3) respectively. (2)
Anatomically, there are usually two umbilical arteries present together with
one of umbilical vein in umbilical cord .the umbilical arteries supply
deoxygenated blood from fetus to placenta. Inside the placenta the umbilical
arteries connect with each other’s at a distance of approximately five millimeter
to branch out intraplacental fetal arteries The umbilical artery is very important
vessel of the fetus, the first vessel to be assessed and has since become the most
widely investigated component of the fetal circulation. The unique umbilical
artery waveform can easily be detected by real time ultrasound associated with
pulse wave Doppler ultrasound (Doppler duplex system). (3)
2
It is essential that each institution should have its own baseline data to apply
to its Sudanese population in evaluation of fetal dynamic status. However, the
relationship between gestational age and Doppler waveform indices in
population has not been established. Therefore, will conduct this study to
establish a normative data of the umbilical artery Doppler waveform indices
(S/D ratio, RI and PI) in normal fetuses in second and third trimester. (3)
2.1 Problem of study:
Assessment of normal Doppler indices of umbilical artery in normal
pregnancy become very important to reduce perinatal mortality and morbidity in
high risk obstetric cases such as (intrauterine growth restriction, preeclampsia
and uteroplacental insufficiently) and this is study to evaluate normative range
of Doppler indices of umbilical artery in fetus.
3.1 Objectives:
3.1.1 General objective:
To assess of Umbilical artery blood flow indices in normal pregnancy using
ultrasonography.
3.1.2 Specific objective:
1-To measure normal umbilical artery Doppler indices (resistive index
pulsitility index and systole to diastole ratio).
2-To correlate gestational age with blood f low indices.
3-To estimate blood flow indices using gestational age.
4-To compare umbilical artery blood flow indices with international results.
2
Chapter two
Literature Review
3
Chapter two
Literature Review
2.1Anatomy of umbilical cord:
The umbilical cord is the lifeline between the fetus and placenta.it is
structure that connects the fetal circulation with the placenta. Its contains two
arteries an one vein and characteristic feature, it is helical structure, is already
developed as early as eight weeks of gestation.it is full length is usually 50-
60cm and diameter generally increase with gestational age . This particular
angioarchitecture and the surrounding Wharton’s jelly protect the blood against
compression, stretching and torsion of umbilical cord. The diameter of
umbilical artery is normally less than 2cm and develop up to 40 spiral turns as it
increase in length during gestation.(3)
2.1.1Development of the umbilical cord:
By the end of the third week of development the embryo is attached to
placenta via a connecting stalk. At approximately 25 days the yolk sac forms
and by 28 days at the level of the anterior wall of the embryo, the yolk sac is
pinched down to a vitelline duct, which is surrounded by a primitive umbilical
ring. By the end of the 5th week the primitive umbilical ring contains a
connecting stalk within which passes the allantois (primitive excretory duct),
two umbilical arteries and one vein, the vitelline duct (yolk sac stalk); and a
canal which connects the intra- and extra embryonic cavities By the 10th week
the gastrointestinal tract has developed and protrudes through the umbilical ring
to form a physiologically normal herniation into the umbilical cord. Normally
these loops of bowel retract by the end of the third month. Occasionally residual
portions of the vitelline and allantois ducts, and their associated vessels, can still
be seen even in term umbilical cords, especially if the fetal end of the cord is
examined.(3)
4
The umbilical cord normally contains two umbilical arteries and one umbilical
vein. These are embedded within a loose, proteoglycan rich matrix known as
Wharton’s jelly. This jelly has physical properties much like a polyurethane
pillow, which if you have ever tried twisting such a pillow you know is resistant
to twisting and compression. This property serves to protect the critical vascular
lifeline between the placenta and fetus. (3)
Figure2.1: Beginning of the umbilical cord. By 21 days the embryo has begun to separate from the
developing placenta by a connecting stalk. (3)
Figure 2.2: Contents and development of the umbilical cord. A, C: At 5 weeks of developing the
embryo is connected to the placenta by a stalk which contains the umbilical vessels and allantois.
Adjacent to this stalk is the yolk sac stalk which consists of the vitelline duct (yolk sac duct) and the
vitelline vessels. These structures all pass through the primitive umbilical ring. B, D: By 10 weeks of
development the yolk sac duct has been replaced by loops of bowel within the umbilical cord. (3)
5
Figure 2.3: Fetus at ~53 days post-ovulation (21.5 mm crown-rump length) showing distinct intestinal
herniation into proximal umbilical cord (arrow). Note twisting of umbilical cord (arrow head). (3)
Figure 2.4: Cross section of normal umbilical cord. Embedded within a spongy, proteoglycan rich
matrix know as Wharton’s jelly (W) is normally two arteries (A) and one vein (V). (3)
Figure2.5: The umbilical cord protects the fetal vessels that connect the placenta and fetus. A) Fetus
and placenta from a 17 week gestation. B) Diagram of the circulation within the fetus, umbilical cord
and placenta. (3)
6
2.1.2Umbilical cord insertion:
The umbilical cord normally inserts near the center of the placenta (see
Figure6). However, in approximately 7% of single births the insertion point
occurs at the very edge of the placenta (marginal insertion) and in about 1% of
cases, the umbilical cord does not insert into the placenta at all, but the fetal
vessels ramify through the external membranes before entering the placenta
(velamentous insertion). When the umbilical cord inserts into the chorionic
plate of the placenta, the fetal vessels are stabilized, and thus protected from
torsional and shear forces. On the other hand, insertion into the membranes
exposes the fetal vessels to the potential for rupture due to shearing forces or if
the vessels pass near the internal cervical os (vasa previa), by rupture due to an
ascending inflammation prior to the time of delivery . (3)
Figure2.6: Insertion of umbilical cord into chorionic plate. Normally the umbilical cord inserts near
the center of the chorionic plate, which stabilizes the fetal vessels as they leave the umbilical cord. (3)
2.1.3Sonographic appearance of the umbilical cord:
The umbilical stalk and the yolk sac are seen as early as 7 week adjacent to
the anterior abdominal wall of the developing fetus.in the second and third
trimester, the umbilical cord is readily visualized .as image in long axis, the
cord may be seen series of parallel line and shorter angled linear interface
arising from the umbilical arteries the wrap around central vein. (8)
7
Figure2.7: Doppler ultrasound of the umbilical cord. In this example the two umbilical arteries and
one vein can be easily seen within the marked off region in the center of the ultrasound image. (8)
2.2 Anatomy and physiology of umbilical artery:
The umbilical artery is a paired artery (with one for each half of the body)
that is found in the abdominal and pelvic regions. In the fetus, it extends into
the umbilical cord. (3)
The umbilical arteries supply deoxygenated blood from the fetus to
the placenta. There are usually two umbilical arteries present together with
one umbilical vein in the umbilical cord. The umbilical arteries surround
the urinary bladder and then carry all the deoxygenated blood out of the fetus
through the umbilical cord. Inside the placenta, the umbilical arteries connect
with each other at a distance of approximately 5 mm from the cord insertion in
what is called the Hyrtl anastomosis subsequently; they branch into chorionic
arteries or intraplacental fetal arteries. (3)
The umbilical arteries are actually the latter of the internal iliac
arteries (anterior division of) that supply the hind limbs with blood and nutrients
in the fetus. The umbilical arteries are one of two arteries in the human body,
that carry deoxygenated blood, the other being the pulmonary arteries. The
pressure inside the umbilical artery is approximately 50 mmHg. (3)
8
The umbilical artery regresses after birth. A portion obliterates to become
the medial umbilical ligament (be careful not to confuse this with the median
umbilical ligament, a different structure that represents the remnant of the
embryonic urachus). A portion remains open as a branch of the anterior division
of the internal iliac artery. The umbilical artery is found in the pelvis, and gives
rise to the superior vesicle arteries. In males, it may also give rise to the artery
to the ductus deferens which can be supplied by the inferior in some individuals.
(3)
2.3 Umbilical artery Doppler assessment:
Doppler is method by which information can be obtained by evaluating the
change in wave form in which the speed and direction of an object can be
determined.in fetal medicine we use the Doppler principle to evaluate change in
sound wave which inform us about the direction and velocity of blood flowing
through the vessels and heart .sing this technology and plotting it against time,
character of blood flow in pregnant women and fetus can be measured. (7)
The umbilical cord normally contains two umbilical arteries and one
umbilical vein .blood flow the umbilical artery originated from fetus and enter
the placenta .the flow of blood through the umbilical arteries is dependent upon
the strength of fetal heart contraction and health of placenta. Blood returning
from the placenta goes through the umbilical vein to the fetus .numerous
medical studies conducted during the past few years have found the
measurement of umbilical arteries using Doppler ultrasound in identifies high
risk fetus .when these fetuses are identified and management is altered by
physician, the fetal death rate as well as other severe complication are markedly
reduced. (7)
9
2.4 Umbilical artery Waveform measured:
The Doppler indices measured at the fetal end, the free loop and the placental
end of the umbilical cord are different with the impedance highest at the fetal
end. The changes in the indices are likely to be seen at the fetal end first. Ideally
the measurements should be made in the free cord. However for consistency of
recording in cases being followed up, a fixed site would be more
appropriate, i.e. fetal end, placental end or intraabdominal portion. (9)
The umbilical arterial waveform usually has a "saw tooth" pattern with flow
always in the forward direction. An abnormal waveform shows absent or
reversed diastolic flow. Before the 15th week, absent diastolic flow may be a
normal finding. The 95% confidence interval limit slowly decreases for both the
resistive index (RI) and pulsitility index (PI) through the course of gestation due
to progressive maturation of the placenta and increase in the number of tertiary
stem villi. (9)
The umbilical artery is evaluated by measuring the blood flow velocity at
peak systole (maximal contraction of the heart) and peak diastole (maximal
relaxation of the heart). These values are then computed to derive a ratio. One
of the most common ratios that are used is the Resistance Index. This is
computed by measuring the peak of systole and then dividing it by the sum of
measurements at peak systole and diastole. RI= (peak systole -end
diastole)/peak systole .In early pregnancy the peak flow at diastole is less than
later in pregnancy. Therefore, as the duration of pregnancy increases, the
amount of blood flowing in the umbilical artery increases during diastole. This
means that the placenta is less resistant to blood flow, thus providing more
blood to flow from the fetus to the placenta. The following image illustrates
Doppler waveforms at 20 and 36 weeks of pregnancy. (9)
10
Figure2.8: illustrates Doppler waveforms at 20 and 36 weeks of pregnancy Systole (Sys) and diastole
(D) are identified in green Note that diastole is less at 20 weeks (yellow ellipse) than at 36 weeks (red
ellipse). (9)
Figre.2.9: Normal umbilical artery Doppler ultrasound in third trimester. (9)
2.5. Doppler Parameters:
The commonly used parameters are:
- Umbilical arterial S/D ratio (SDR): systolic velocity / diastolic velocity.
- Pulsitility index (PI) (Gosling index): (PSV - EDV) / TAV.
- Resistive index (RI) (Pourcelot index): (PSV - EDV) / PSV.
- PSV: Peak systolic velocity.
11
- EDV: End diastolic velocity.
- TAV: Time averaged velocity.(9)
The Doppler indices have been found to decline gradually with gestational age:
- S/D ratio mean value decreases from 3.560 to 2.511.
- RI mean value decreases from 0.756 to 0.609.
- PI main value decreases from 1.270 to 0.967. (9)
2.6 Benefits of umbilical artery surveillance:
Recent studies have found that surveillance of high-risk fetuses with
umbilical artery Doppler ultrasound results in a marked decrease in fetal death
and morbidity when compared to traditional surveillance (non-stress test). For
this reason, all fetuses with suspected intrauterine growth restriction should
undergo umbilical artery Doppler evaluation. (9)
2.7 Factor affect flow velocity wave form:
2.7.1 Maternal position:
During Doppler studies, the mother should lie in a semi recumbent position
with a slight lateral tilt. This minimizes the risk of developing supine
hypotension syndrome due to caval compression. (9)
2.7.2 Artifactual loss of end-diastolic frequencies:
A high angle between the ultrasound beam and the vessel results in very low
frequencies disappearing below the height of the vessel wall filter. (9)
If end-diastolic frequencies appear absent you should reduce the vessel wall
filter to its lowest setting, or remove it if possible. Then you should alter the
angle of the probe relative to the maternal abdomen to reduce the angle of
insonation. If enddiastolic frequencies are still absent you should then attempt to
obtain the signal from a different site, because this is likely to result in a
different angle of insonation. Do not report the absence of end-diastolic
frequencies until this has been demonstrated on two successive days. (9)
12
2.7.3 Fetal breathing movements:
These cause wild fluctuations in the signal from the umbilical artery and are
readily recognizable by an inability to demonstrate a steady state in the
umbilical arterial signal. The only course of action to take if the fetus is
breathing. (9)
Figure (2.10): Fluctuations in the waveform of the ductus venous due to fetal breathing
movements during vessel interrogation. (9)
2.7.4 Fetal heart rate:
There is an inverse relation between fetal heart rate and length of cardiac
cycle and, therefore, fetal heart rate influences the configuration of the arterial
Doppler waveform. When the heart rate drops, the diastolic phase of the cardiac
cycle is prolonged and the end-diastolic frequency shift declines. Although the
Doppler indices are affected by the fetal heart rate, the change is of no clinical
significance when the rate is within the normal range .Fetal bradycardia is
associated with decreased enddiastolic frequencies. When reporting Doppler
indices, you should check to ensure that the fetal heart rate is in the normal
range. (9)
2.7.5 Blood viscosity:
Previous studies have demonstrated that increased blood viscosity is
associated with reduced cardiac output and increased peripheral resistance, and
vice versa. However, Giles et al. were unable to demonstrate a significant
13
association between blood viscosity (measured in post-delivery umbilical cord
blood) and impedance to flow in the umbilical artery. (9)
2.8 The Safety of Doppler for the Obstetric Pregnancy:
Doppler ultrasound provides a noninvasive method to assess the physiology
and pathophysiology of fetal and maternal circulations when such examinations
are required for diagnosis. In most cases, pulsed wave Doppler rather than
continuous wave Doppler is used in the fetus. (9)
Doppler may be used to detect flow in the maternal vessels, the fetal vessels
(umbilical artery and vein, aorta and inferior vena cava, renal arteries, and
cerebral vessels), the fetal ductus venosus, the fetal heart, and the placenta.
Doppler interrogation is an important part of fetal echocardiography
examinations and aids in the diagnosis of fetal heart defects. Specific
applications of Doppler in obstetrics are presented in the respective chapters.
Recently, several authors have demonstrated the feasibility of examining the
fetal heart during the first trimester. Doppler is performed at a higher energy
level because these are difficult examinations that may require prolonged dwell
times, and because the embryo at this stage is small and receives total body
insonation Therefore, the use of Doppler ultrasound during the first trimester
has generated some controversy. (9)
It is the responsibility of sonographers to integrate their knowledge of
bioeffects into their scanning. In March 2008, the AIUM adopted a statement on
the As Low as Reasonably Achievable (ALARA) principle, which states the
following: The potential benefits and risks of each examination should be
considered. The ALARA (As Low As Reasonably Achievable) principle should
be observed when adjusting controls that affect the acoustical output and by
considering transducer Dwell times. (9)
14
2.9 Background studies:
In study done by Pharuhas Chanprapaph, Chanane Wanapirak and Theera
Tongsong under title Umbilical Artery Doppler Waveform Indices in Normal
pregnancies, in Thai Journal of Obstetrics and Gynecology, June 2000, Vol. 12,
pp. 103-107. A total of 332 normal singleton pregnant women were recruited
into the study from the antenatal care clinic between September 1, 1994 and
August 1, 1996. Their gestational ages were from 21 to 40 weeks. The S/D
ratio, RI and PI of the umbilical arteries were obtained by the same
sonographer. All fetuses were delivered at term with normal outcomes at birth.
Main outcome measures Means with 95% confidence intervals of the 3 Doppler
indices for each gestational week. The obtained result was the total of 411
Doppler indices measurements was performed. The values of S/D ratio, RI, PI
declined gradually with gestational age. The mean values decreased from 3.560
to 2.511, 0.756 to 0.609 and 1.270 to 0.967, respectively. Doppler indices
declined rapidly from 21 to 32 weeks, when compared to that in the last 8
weeks. Notably, the S/D ratio was less than 3 after 30 weeks of gestation. In
Conclusion the nomogram of umbilical artery Doppler waveform indices was
constructed and showed the decreasing of Doppler indices with gestational age.
These normative data could be served as a basis for evaluation the umbilical
artery circulation in Thai population.
In study done by Ganesh Acharya, Tom Wilsgaard andTorvid Kiserud under
title Reference ranges for serial measurements of umbilical artery Doppler
indices in the second half of pregnancy, American Journal of Obstetrics and
Gynecology March 2005, Vol.192(3):937–944. This was a prospective
longitudinal study of the umbilical artery Doppler indices that were obtained
serially at the free-loop of umbilical cord at 4-week intervals at 19 to 42 weeks
of gestation in 130 low-risk singleton pregnancies. A total of 513 observations
were used to construct the reference ranges with the use of multilevel
15
modelling. The obtained result was longitudinally established percentiles of
Doppler indices from the present study show a continuous reduction throughout
the second half of pregnancy without any plateau or increase near term, as
reported previously. There was a significant negative association between
Doppler indices and placental weight and neonatal birth weight, but not with
gender. The intraobserver coefficients of variation for the umbilical artery
pulsitility index, resistance index, and systolic: diastolic ratio was 10.5%, 6.8 %,
and 13.0 %, respectively. In conclusion, new reference ranges for umbilical
artery Doppler indices that are based on longitudinal observations appear to be
slightly different from cross-sectional studies and are more appropriate for serial
evaluation of fetal hemodynamic.
In study done by brian j. trudinger,warwick b. giles,colleen. ,john
bombardieriandlee collins, b. j. trudinger, department of obstetrics, university of
sydney, westmead hospital, westmead, new south wales 2145 Volume 92, Issue
January 1985 ,Pages 23–30 Australia. Under title fetal umbilical artery flow
velocity waveforms and placental resistance: clinical significance. Since the
umbilical arteries carry fetal blood to the placenta they studied flow velocity
waveforms in these vessels with a simple continuous wave Doppler system to
assess placental blood flow. The ratio of peak systolic to least diastolic (A/B)
flow velocity was measured as an index of placental flow resistance. In 15
normal pregnancies there was a small but significant decrease in this ratio
through the last trimester. The A/B ratio was measured on 436 occasions in 168
high-risk pregnancies. In 32 of 43 fetuses subsequently shown to be small for
gestational age there was an increase in placental flow resistance with reduced,
absent or even reversed flow in diastole. This finding was also present in the
one fetus which died in utero. Serial studies in patients with fetal compromise
indicated increasing flow resistance, a reverse of the normal trend. These results
were not available to the clinician yet of 24 fetuses born before 32 weeks 13 had
16
a high A/B ratio, and all of them were born electively. Maternal hypertension
was associated with an increase in fetal placental flow resistance. The umbilical
artery A/B ratio provides a new and non-invasive measure of fetoplacental
blood flow resistance.
In study done by kevin p. hanretty, mairi h. primrose, james p. neilson, martin
j.and whittle, First published:October Cited by (CrossRef):45 articlesvolume
92, issue 1 january 1985 pages 39–45 .under title Pregnancy screening by
Doppler uteroplacental and umbilical artery waveforms. 543 unselected women
attending an antenatal clinic were studied .Doppler waveforms from the
uteroplacental and umbilical arteries Overall, 357 women were studied at 26–30
weeks and 395 at 34–36 weeks; 209 were studied at both gestation periods.
Results were not made available to clinicians. There was no difference in
outcome of pregnancies between those with normal and abnormal uteroplacental
waveforms, but birth weights were significantly lower in those with an
abnormal umbilical artery waveform at either gestation. There were no other
statistically significant differences between groups. Although the power of the
study to detect differences in outcome in this sample size is limited, our findings
do not support the introduction of this new technique into clinical practice
before sufficiently large randomized controlled trials have shown some benefit.
16
Chapter Three
Materials and methods
17
Chapter Three
Materials and methods
3.1. Design of study:
A cross-sectional descriptive study deal with assessment of umbilical artery
blood flow indices in normal pregnancy using ultrasonography conducted in
Khartoum Bahri hospital in period August 2017 to November 2017.
3.2. Sample:
Asymptomatic hundreds of the normal pregnant women attended to
diagnostic ultrasound department. They were in gestational age between (24-40)
weeks. The study used the random sampling technique.
Inclusion criteria:
Consisting of normal singleton pregnancy and known definite gestational age.
Exclusion criteria:
The pregnancy with fetal anomalies, twin’s pregnancy, underlying chronic
disease and abnormal fetal growth.
3.3. Machine:
General electric (GE) Mindary DC-6diagnostic ultrasound system with 3.5-5
MHz curvilinear probe used for studying umbilical artery.
3.4. Method:
The data for this study were derived from prospective screening for adverse
obstetric outcomes in women attending to hospital for their routine follow up
which is attended at 24 to 40weeks gestation, included the recording of maternal
characteristics and medical history, and estimation of fetal size from
Transabdominal ultrasound curvilinear transducers of 3.5 MHz, measurement of
fetal head circumference, abdominal circumference and femur length.
Transabdominal color Doppler ultrasound was used to visualize the Umbilical
artery. Pulsed-wave Doppler was then used to assess impedance of flow, and
measuring of the Doppler indices (mean average of S/D Ratio, RI and PI were
18
recorded in each gestational week) measured during fetal scan by the same
examiner at the free loop site where the clearest waveform signal visualized.
3.5. Study variable:
Gestational age, femur length, LMP, resistive index, pulsitility index and S/D
ratio.
3.6. Method of data analysis:
Data were analyzed using SPSS program.
3.7 Data storage;
All data collected during the study stored on CD, personal computer, data
collection sheets and ultrasound images.
3.8. Data presentation:
The present data were in tables, figures.
3.9. Ethical consideration:
Participants informed about the plan of dissemination and publication of
research findings, also they assured that data released only after elimination of
all identifications, and verbal consent will be obtained.
18
Chapter Four
Results
19
Chapter Four
4. Results
This research aim to establish a normative data of the umbilical artery Doppler
waveform indices (resistive index pulsitility index and systole to diastole ratio)
in normal fetus using ultrasonography
The following table and figure presented the information about the variable
including gestation age, femur length, resistant indices, pulsitility indices, and
S\D ratio mean values. Correlation between gestational age with last menstrual
period ,gestational age with femur length , resistive indices ,pulsitility indices
and S/D ratio were also been presented in figures.
Table 4:1 illustrated mean, stander deviation, minimum and maximum of the variables.
Variables N Minimum Maximum Mean Std. Deviation
GA/ LMP/ weeks 100 25.00 40.00 35w4d 3.64184
GA/FL/weeks 100 24.00 40.00 34w2d 3.65301
GA/average/week 100 25.00 40.00 34w6d 3.60272
FL/cm 100 5.00 7.80 6.5900 .69856
RI 100 .49 .77 .6001 .06807
PI 100 .64 1.20 .8703 .12189
S/D ratio 100 2.00 4.00 2.6017 .48064
20
Figure 4.1: a scatter plot diagram represent linear relationship between the RI, PI, S\D ratio (Y
axis) and GA-FL (X axis) in normal pregnancies. The RI, PI, S\D ratio decreased by 0.008,
0.0129, and 0.0592 respectively as gestational age increased.
Figure 4.2: a scatter plot diagram represent linear relationship between the RI, PI, S\D ratio (Y
axis) and GA-AVG (X axis) in normal pregnancies. The RI, PI, S\D ratio decreased by 0.0082,
0.0131, and 0.0595 respectively as gestational age increased
RI = -0.008GA FL + 0.874
R² = 0.1841
PI = -0.0129GA FL + 1.3111
R² = 0.1487
SD ratio= -0.0592 GA FL + 4.6289
R² = 0.2022
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0 5 10 15 20 25 30 35 40 45
RI
\PI
\S\D
ra
tio
GA FL weeks
RI = -0.0082 GA AVG + 0.8854 R² = 0.1858
PI = -0.0131 GA AVG + 1.3281 R² = 0.1492
S\D ratio = -0.0595 GA AVG+ 4.6853 R² = 0.1988
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0 10 20 30 40 50
RI \
PI \
SD r
atio
GA AVG weeks
21
Figure 4.3: a scatter plot diagram represent linear relationship between the RI, PI, S\D ratio (Y
axis) and GA-LMP (X axis) in normal pregnancies. The RI, PI, S\D ratio decreased by 0.0077,
0.0124, and 0.0562 respectively as gestational age increased.
Figure 4.4: a scatter plot diagram represent variant between GA-FL (Y axis) and GA-LMP (X
axis) in normal pregnancies .the gestational age by femur length variance from gestational
age by last menstrual period by 0.979.
RI = -0.0077 GA LMP + 0.8752
R² = 0.1706
PI= -0.0124 GA LMP + 1.3135
R² = 0.1381
S\D ratio = -0.0562 GA LMP + 4.604
R² = 0.1812
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0 5 10 15 20 25 30 35 40 45
RI
\OI
\S\D
ra
tio
GA LMP weeks
y = 0.979x - 0.6286 R² = 0.9525
0
5
10
15
20
25
30
35
40
45
0 10 20 30 40 50
GA
FL
GA LMP
22
Figure 4.5: a scatter plot diagram represent variant between GA-FL (Y axis) and GA-LMP (X
axis) in normal pregnancies .the gestational age by femur length variance from gestational
age by last menstrual period by 0.980.
Figure 4.6: a scatter plot diagram represent variant between GA-FL (Y axis) and GA-AVG
(X axis) in normal pregnancies .the gestational age by femur length variance from gestational
age by last menstrual period by 0.979
y = 0.9809x + 0.0274 R² = 0.9837
0
5
10
15
20
25
30
35
40
45
0 5 10 15 20 25 30 35 40 45
GA
AV
G
GA LMP
y = 0.9794x + 1.4317 R² = 0.9867
0
5
10
15
20
25
30
35
40
45
0 10 20 30 40 50
GA
AV
G
GA FL
23
Table (4.2) correlation between of RI , PI and S\D ratio in relation to GA LMP , GA FL and
GA AVG weeks
GA LMP RI PI SD GA FL GA AVG
GA LMP Pearson Correlation 1 -.413**
-.372**
-.426**
.976**
.992**
Sig. (2-tailed) .000 .000 .000 .000 .000
N 100 100 100 100 100 100
RI Pearson Correlation -.413**
1 .838**
.885**
-.429**
-.430**
Sig. (2-tailed) .000 .000 .000 .000 .000
N 100 100 100 100 100 100
PI Pearson Correlation -.372**
.838**
1 .854**
-.386**
-.386**
Sig. (2-tailed) .000 .000 .000 .000 .000
N 100 100 100 100 100 100
SD Pearson Correlation -.426**
.885**
.854**
1 -.450**
-.445**
Sig. (2-tailed) .000 .000 .000 .000 .000
N 100 100 100 100 100 100
GAFL Pearson Correlation .976**
-.429**
-.386**
-.450**
1 .993**
Sig. (2-tailed) .000 .000 .000 .000 .000
N 100 100 100 100 100 100
GA
AVG
Pearson Correlation .992**
-.430**
-.386**
-.445**
.993**
1
Sig. (2-tailed) .000 .000 .000 .000 .000
N 100 100 100 100 100 100
**. Correlation is significant at the 0.01 level (2-tailed).
23
Chapter five
Discussion, conclusion, recommendations
and references
24
Chapter five
5.1 Discussion:
This study was carried out to establish a normative data of the umbilical
artery Doppler waveform indices (resistive index pulsitility index and systole to
diastole ratio) in normal fetus using ultrasonography. This study includes 100
women with singleton normal pregnancy in 24-40 weeks of gestation.
The study found that, the higher gestational age with last menstrual period
was40 weeks and minimum gestational age was 25 weeks with mean was 35
weeks 4 days and stander deviation was 3.64. The higher gestational age by
femur length was 40 weeks and the lower gestational age 24 weeks with
mean34w2d and stander deviation 3.65. The higher femur length with was
7.8cm and lower femur length was 5cm with mean was 6.59 and stander
deviation was0.698.because as gestational age increase femur length increase
due to fetal development. The higher resistive index was 0.77 and lower
resistive index 0.49with mean was0 .6 with slandered deviation 0.068. The
higher pulsitility index was 1. 2 and lower resistive index 0.64with mean was
with 0.87 stander deviation 0.12. The higher S/D ratio was 4 and the lower S/D
ratio 2with mean was with 2.61 stander deviation 0.48.
The results of this study showed that there is an inverse linear relationship
between the RI, PI and S/D Ratio and GA-FL. The resistive index, decreased by
0.008 per week as gestational age increased, this is because of the resistance to
blood flow in the umbilical arteries falls with advances of gestation due to
continuing development of the placental vascular system throughout pregnancy.
The pulsitility index decreased by 0.0129/week as gestational age increase, this
is generally due to the facts that as gestational age increased. The resistance of
blood decreases in the fetoplacental flow resistance as a result of continuous
development of the placental vascular system in respect to time factor.
25
The S/D Ratio decreased by 0.0592/week as gestational age increased,
because as gestational age increased S/D ratio decreased due to increasing in the
end diastolic velocity. Subsequently resistance to blood flow in the umbilical
arteries falls due to continuing development of the placental vascular system
throughout pregnancy decline in the fetoplacental flow resistance.
The Study found that, there is inverse linear relationship between the RI, PI
and S\D ratio (Y axis) and GA-AVG (X axis) in normal pregnancies. The RI, PI
and S\D ratio decreased by 0.0082, 0.0131, and 0.0595 respectively as
gestational age increased this is because of the resistance to blood flow in the
umbilical arteries falls with advances of gestation due to continuing
development of the placental vascular system throughout pregnancy.
The Study found that, there is inverse linear relationship between the RI, PI,
S\D ratio (Y axis) and GA-LMP (X axis) in normal pregnancies. The RI, PI,
S\D ratio decreased by 0.0077, 0.0124, and 0.0562 respectively as gestational
age increased. This is because of the resistance to blood flow in the umbilical
arteries falls with advances of gestation due to continuing development of the
placental vascular system throughout pregnancy.
The Study found that, the estimation of GA-FL was similar to GA-LMP and
GA –average 0.976, 0.993 and 0.992 respectively.
On the other hand estimation of gestational age results indicates a good
correlation between the three estimated gestational ages although estimation
using femoral length it seem to under estimate the gestational age respectively
but still it is within the ±2 weeks limits.
The study found that, When the gestational age was 26 weeks the mean of
indices were 0.77, 1.2 and 4 respectively. When the gestational age was 28
weeks the mean of indices were 0.70, 1.0 and 3.5 respectively. When the
gestational age was 31 weeks the mean of indices were 0.66, 0.99 and 3.05
respectively. When the gestational age was 33 weeks the mean of indices were
26
0.61, 0.88 and 2.7 respectively. When the gestational age was 34 weeks the
mean of indices were 0.56, 0.81 and 2.3 respectively.
In general of the results of this study agree with previous studies which done
by (Ganesh Acharya, Tom Wilsgaard ,Torvid Pharuhas Chanprapaph, Chanane
Wanapirak and Theera Tongsong) showed that there is an inverse linear
relationship between the RI, PI S/Ratio and gestational age. Because as
gestational age increase the development of the placental vascular system
throughout pregnancy continues increase and the end diastolic velocity increase
therefor, Doppler indices (RI PI S/D ratio) decreased. But it showed minimum
variance of value of Doppler indices compared with study done by Pharuhas
Chanprapaph, Chanane Wanapirak and Theera Tongsong to for evaluation the
umbilical artery circulation in Thai population. ; This is study result (0.77-0.49)
(1, 2-0.64) (4-2) respectively. Previous study result values of RI, PI S/D ratio
was (0.756 to 0.609) (1.270 to 0.967) (3.560 to 2.511) respectively. As well it
might be due to the ethnic group because the built in equation has been
developed in a nation possesses different body characteristics than Sudanese
one.
27
5-2 conclusion:
The main objective of this study was to obtain normative data for umbilical
artery in the third trimester pregnancy.
The study found that the Doppler indices of umbilical artery range in age
group from (24-40 weeks) were 0.47-0.77, 0.64-1.2 and 2-4 for RI, PI and S/D
ratio respectively.
The normal of umbilical artery Doppler waveform indices which include; S/D
ratio, RI and PI showed a mean value of 2.61±0.48, 0.6±0.068 and 0.87±0.12
respectively.
The indices values decreases as a results of advances of gestational age i.e. in
respect to fetal development; where resistivity decrease accordingly, therefore
indices should be taken relative to gestational age.
28
5.3 Recommendations:
Assessment of umbilical artery blood flow is noninvasive exam should be
used as routine screening test in third trimester to improve the outcome.
Doppler ultrasound should be part of setup of every unit that provides
antenatal medical service with good expertise and well trained examiner.
Early screening of umbilical artery wave form should be performed to all
high risk patient this may help in early diagnosis of preeclampsia and may
decrease the maternal morbidity and mortality.
Inaccurate information concerning fetal Doppler studies may lead to
inappropriate clinical decision, it is essential that measurement be
undertaken and interpreted by expert operator who are knowledgeable
about the significance of Doppler changes and practice appropriate
techniques.
Further research should also focus on combining umbilical artery Doppler
ultrasound with other test that used in clinical care; this may improve the
predicative accuracy and the clinical important value of the tests.
29
References:
1-Sandra-L.Hagen.Ansert.Textbook of Diagnostic Sonography.7thed
.Elsevier.Mosby; California: 2012. P (1139-1166).
2-https://www.slideshare.net/mobile/drabhishekgupta9/doppler-in-
pregnancy.2september 2017
3- Harvey J. Kliman. The Umbilical Cord. The Encyclopedia of Reproduction;
Yale University School of Medicine: Sunday October 29. 2006. P (2-14).
4-Pharuhas Chanprapaph, Chanane Wanapirak and Theera Tongsong. Umbilical
Artery Doppler Waveform Indices in normal pregnancies. Journal of Obstetrics
and Gynecology; Thai :June 2000. Volume12. P (103-107).
5- Ganesh Acharya. Tom Wilsgaard and Torvid Kiserud. Reference ranges for
serial measurements of umbilical artery Doppler indices in the second half of
pregnancy. American Journal of Obstetrics and Gynecology; Elsevier: 2005.
Volume192 (3) .P (937–944).
6- Brian j. trudinger Warwick. Giles colleen. Cook john. Trudinger.
Department of obstetrics. University of Sydney; Australia Westmead hospital: 1
January 2000 .Volume 92. P (23–30).
7- Asim Kurjak. Donald School Textbook of Ultrasound in Obstetrics and
Gynecology. 3rd
edition. Jape Brothers Medical; New York: 2011.P (500-515).
8- Carol MD RumackCM. Wilsons. Charbonneau. Levine. Diagnostic
ultrasound. 4th
ed. Elsevier Mosby; Library of Congress: 2011. P (1515-1520).
23
Appendices
24
Appendix (A)
Data collection sheet
The National Ribat University
College of Graduate Studies and Scientific Research
Evaluation of Umbilical artery blood flow indices in normal
pregnancy using ultrasonography
NO Gestational
age LMP
GA -FL GA Average PI RI S/D
ratio
25
Appendix (B)
Ultrasound images
image no1:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(31week)show an arterial waveform with forward flow throughout the cardic cycle and
relatively high end diastolic flow resulting in low dopler indices.RI=0.71 PI=1 S/D=3.4.
image no 2:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(32week)show an arterial waveform with forward flow throughout the cardic cycle and
relatively high end diastolic flow resulting in low dopler indices.RI=0.63 PI=0.94 S/D=3.
26
image no3:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(37week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.64 PI=0.94
S/D=2.7.
image no 4:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(37week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.51 PI=0.68 S/D=2.
27
Image no 5:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(32week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.53 PI=0.7
S/D=2.1.
Image no 6:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(38week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.53 PI=1 S/D=3
28
Image no 7:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(30week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.63 PI=0.90
S/D=2.7.
Image no 8:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(33week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.64 PI=0.94
S/D=2.7.
29
.
Image no 9:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(36week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.53 PI=0.70
S/D=2.1.
Image no 10:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(35week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.64 PI=0.94
S/D=2.8.
30
Image no11:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(39week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.51 PI=0.7 S/D=2.
Image no 12:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(34week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.69 PI=1 S/D=3.2.
31
Image No13:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(37week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.63 PI=0.95
S/D=3.
Image no14:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(37week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.68 PI=0.85
S/D=2.8.
32
`
Image No 15:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(36week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.65 PI=0.94
S/D=2.8.
Image No16:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(34week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.65 PI=1 S/D=2.9.
33
Image no17:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(38week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.64 PI=0.90
S/D=2.5.
image no 18:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(33week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.64 PI=0.96
S/D=2.8.
34
image no19:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(36week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.60 PI=0.78
S/D=3.3.
Image no20:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(35week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.61 PI=0.90
S/D=2.5.
35
Image no21:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(36week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.49 PI=0.64 S/D=2.
Image no22:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(32week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.71 PI=1 S/D=3.5.
36
Image no23:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(3week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively hig h end diastolic flow resulting in low dopler indices.RI=0.64 PI=0.96
S/D=2.8.
.
Image no24:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(36week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.67 PI=1
S/D=3.07.
37
Image no25:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(33week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.60 PI=0.80
S/D=2.47.
Image no26:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(34week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.51 PI=0.70
S/Dratio=2.
38
Image no27:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(40week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.59 PI=0.83
S/Dratio=2.4.
Image no22:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester (34week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.56 PI=0.78
S/D=2.2.
39
Appendix No22:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(39week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.53 PI=0.70
S/Dratio=2.1.
Appendix No30:show normal umbilical artery velocity.spectrial doppler of the UA in third
trimester(32week)show an arterial waveform with forward flow throughout the cardic cycle
and relatively high end diastolic flow resulting in low dopler indices.RI=0.95 PI=1
S/Dratio=2.8.
40
Appendix (c)
Table (5.1) compare mean for measurement of RI, PI and S\D ratio in relation to GA LMP weeks.
GA b LMP RI PI SD
25 Mean .6500 1.0000 3.2000
26 Mean .7700 1.2000 4.0000
27 Mean .6700 .9667 3.1000
Std. Deviation .05196 .05774 .45826
28 Mean .7000 1.0000 3.5000
29 Mean .6367 .9400 2.9000
Std. Deviation .04726 .06557 .36056
30 Mean .6000 .8500 2.4000
31 Mean .6650 .9950 3.0500
Std. Deviation .02121 .00707 .07071
32 Mean .6120 .8940 2.6000
Std. Deviation .03899 .05639 .18708
33 Mean .6191 .8845 2.7182
Std. Deviation .07803 .15267 .56182
34 Mean .5650 .8150 2.3000
Std. Deviation .06403 .05972 .25820
35 Mean .6200 .9433 2.8167
Std. Deviation .06573 .07633 .44907
36 Mean .5930 .8560 2.5600
Std. Deviation .06832 .12030 .53996
37 Mean .6125 .8850 2.6481
Std. Deviation .05698 .11679 .41584
38 Mean .5533 .7683 2.2750
Std. Deviation .07127 .12097 .42239
39 Mean .5858 .8300 2.4583
Std. Deviation .05518 .11144 .34234
40 Mean .5658 .8542 2.4333
Std. Deviation .06127 .10405 .41851
Total Mean .6001 .8703 2.6017
N 100 100 100
Std. Deviation .06807 .12189 .48064
41
Table (5.2) compare mean for measurement of RI, PI and S\D ratio in relation to GA FL weeks.
GA FL RI PI SD
24 Mean .7700 1.2000 4.0000
25 Mean .6533 .9667 3.1000
Std. Deviation .04509 .05774 .45826
26 Mean .7000 1.0000 3.3500
Std. Deviation .00000 .00000 .21213
27 Mean .6900 1.0000 3.2000
28 Mean .6000 .8600 2.4500
29 Mean .6200 .9500 3.0000
30 Mean .6467 .9400 2.8333
Std. Deviation .02887 .05292 .23094
31 Mean .6329 .9343 2.8143
Std. Deviation .07342 .14853 .50143
32
Mean .5887 .8300 2.4875
Std. Deviation .07019 .10850 .53033
33 Mean .6017 .8667 2.7000
33 w2d Mean .6500 .9500 2.8000
33w3d Mean .6500 .9600 2.8000
34 Mean .6188 .9075 2.7500
Std. Deviation .07396 .13221 .58064
35 Mean .5910 .8850 2.5400
Std. Deviation .05587 .10384 .41687
35w5d Mean .6700 1.0000 3.0700
36 Mean .5714 .8150 2.4071
Std. Deviation .07843 .13883 .49531
37 Mean .5853 .8093 2.4333
Std. Deviation .05668 .10694 .33523
38 Mean .5686 .8843 2.4714
Std. Deviation .04981 .09641 .35456
38w3d Mean .5600 .7700 2.2000
38w5d Mean .6000 .9000 2.5000
39 Mean .5600 .7750 2.4000
Std. Deviation .10100 .15000 .66833
39w5d Mean .5900 .8300 2.4000
40 Mean .5500 .8500 2.2500
Std. Deviation .07071 .07071 .35355
Total Mean .6001 .8703 2.6017
Std. Deviation .06807 .12189 .48064
42
Table (5.3) compare mean for measurement of RI, PI and S\D ratio in relation to GA-AVG weeks.
GA AVG RI PI SD
25 Mean .7100 1.1000 3.6000
Std. Deviation .08485 .14142 .56569
26 Mean .6550 .9500 3.0500
Std. Deviation .06364 .07071 .63640
27 Mean .7000 1.0000 3.5000
28 Mean .6900 1.0000 3.2000
28w5d Mean .6000 .8700 2.5000
29 Mean .6100 .9000 2.7000
Std. Deviation .01414 .07071 .42426
30w5d Mean .6800 1.0000 3.1000
31 Mean .6367 .9367 2.8000
Std. Deviation .01155 .04726 .17321
31w5d Mean .5750 .8500 2.4000
Std. Deviation .03536 .07071 .00000
32 Mean .6575 .9625 2.9750
Std. Deviation .08500 .18875 .58523
32w5d Mean .6200 .8780 2.7400
Std. Deviation .06856 .12418 .55946
33 Mean .5980 .8480 2.4200
Std. Deviation .04712 .06723 .26833
33w5d Mean .5000 .7300 2.1000
Std. Deviation 0.000 0.04243 0.14142
34 Mean .6325 .9150 2.9250
Std. Deviation .02363 .08062 .22174
34w5d Mean .5950 1.0000 2.6000
Std. Deviation .13435 .00000 .84853
35 Mean .6267 .8767 2.8000
Std. Deviation .06121 .14109 .56214
35w5d Mean .5700 .8900 2.4000
Std. Deviation .05657 .01414 .14142
36 Mean .5825 .8575 2.4725
Std. Deviation .06468 .12563 .48672
36w5d Mean .6533 .9667 2.9667
Std. Deviation .00577 .03055 .05774
37 Mean .5791 .7982 2.4182
Std. Deviation .08031 .13423 .44681
37w5d Mean .5550 .7500 2.2000
Std. Deviation .04950 .07071 .28284
38 Mean .5755 .8073 2.4000
Std. Deviation .05592 .11118 .35496
38w5d Mean .5800 .8367 2.4000
Std. Deviation .07211 .13051 .40000
39 Mean .5643 .8786 2.4429
Std. Deviation .03952 .08275 .31015
39w5d Mean .5800 .8000 2.5333
Std. Deviation .11358 .17321 .75056
40 Mean .5500 .8500 2.2500
Std. Deviation .07071 .07071 .35355
Total Mean .6001 .8703 2.6017
Std. Deviation .06807 .12189 .48064