fertilization and conception

7/27/2019 Fertilization and Conception

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Fertilization and Conception


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Intrauterine life reaches full term 9 calender months, 40

weeks, or 280 days.

Fertilization occurs when one sperm penetrates the ovum

Fertilization of the ovum takes place in the outer 1/3 of thefallopian tube and occurs within 24 hours of the ovums

release.

The newly formed organism, known as a zygote, has a 22pairs of autosomal chromosomes.


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The zygote, has three distinct cell layers

- endoderm (inner layer) respiratory, digestive, liver, and

the pancreas system

- mesoderm ( middle layer) skeleton, connective tissue,cartilage, muscle and the circulatory, lymphoid,

reproductive and urinary system.

- ectoderm ( outer layer) the brain, spinal cord, nervous,and outer body parts ( skin, hair, and nails)


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The zygote moves through the fallopian tube uterus

within 3 to 4 days.

Within 3 days a solid ball of cell Morula has formed

forms central cavity Blastocyst. Cell at the end of the blastocyst develop into the Embryo,

and those at the opposite end will begin to form the

placenta.

Between days 6 and 10, enzymes are secred that allow the

blastocyst to burrow into endometrium and become

completely covered Implantation


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Chorionic villi, fingerlike projections, develop to obtain oxygen and

nutrition from the maternal blood supply and dispose of carbon

dioxide and waste products


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The placenta produces essential hormones that help

maintain the pregnancy.

The placenta is extremely porous, noxious materials such

as viruses and drugs can also pass from mother to child. The effect of noxiuous agent on unborn child depends on

the developmental stage; embriyonic stage being the most

crucial

This is a crucial stage in the development of organ

systems and the main external features.


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The period gestation is devided :

1. First trimester

2. Second trimester

3. Thirt trimester


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First Trimester

Physical changes

- the first 3 calender months:

1. fetal cell continue to differentiate and develop into

essential organs system

2. interference with growth can cause the congenital

absence of a organ system or extensive structural or

functional alterations.3. disruption of one system often occurs with disruption

of others


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At the end of the first trimester, some reflexes are present,

kidney secretion begins, the heart beat can be heard by

Doppler

The sex of the infant is distinguishable by outwardappearance


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Health promotion

- three risk factors have been possible effect on prenatal

development : nutrition, stress, and mothers age

1. Nutritiona. Folic acid intake is encouraged decreasing the

incidence of neural tube defects

b. Morning sickness, report excessive nausea and vomiting

2. Avoid exposure to teratogenic agents, such as : rubelle or Germanmeasles virus, drugs, smoking, alcohol, caffeine


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Second Trimester

Physical changes

- measurement of the height of the uterus above the

symphysis pubis is one indicator of fetal growth

- by the end of the 6th month, most system are completeand can function

- finger and toes are differentiated, rudimentary kidney

function, and the sex of the fetus can be determined- covered with vernix caseosa and lanugo.


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fetal heart tones are audible by stethoscope

the liver and pancreas are functioning

hair forms

sleepwake pattern are established

lung surfactant is produced

eyelibs open.


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Health promotion

- include planning for the birth

- concern for personal safety

- gestational events and appropriate maternal rest- nutrition

- dental care

- physical activity

- posture

- employment

- infant feeding options


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Cont..

- UTI increase the risk of preterm labor discuss proper

voiding

- Education to recognize potential complications

- Prematurity, causes: physiological stresses, poverty,smokers and poor prenatal care; potential: multiple

pregnancies and fetal infections; abruptio placentae and

placenta plevia


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Third Trimester

Physical Changes

- the fetus grows to approximately 50 cm in length

- subcutaneous fat is stored, and weight increases to between 3.2

dan 3.4 kg.- the skin thickens, lanugo begins to disappear

- fetal body becomes rounder and fuller

- a tremendous spurt in brain growth

- the CNS has established its total number of neurons andconnections between neurons, and myelination of nerve fibers

prgresses at a rapid rate


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- able to make tha transition from intrauterine to extrauterine life.

- cardiac system can change its circulation to end bypassing of the

lungs

- the lungs are capable of maintaining the inflanted state for gasexchange.

- temperature maintenance systems, reflexes, and sensory organs

are ready for use


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Health promotion

- preparing her mind and body for the delivery.

- information regarding the childbirth process and breast- feeding

- assess the couples strengths and weaknesses. Cognitive changes

- periods of diminished oxygen (anoxia) during fetal life are known to

cause deficits in later cognitive functioning,

- inadequate prenatal nutrition has been associated with lower brainweight


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- infant with LBW and VLBW indicates increased risk for

learning disorders, school failures, temperament problems,

neurological and motor impairment and developmental

delay. Psychosocial changes

- nutritional deficiencies of the fetus can significantly

influence later psychosocial development.


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Transition From Intrauterine to Extrauterine Life

Physical Changes

- circulatory, pulmonary, and thermal changes

nurse maintaining an open airway, stabilizing and

maintaining body temperature, and protecting the newbornfrom infection

- assess APGAR Score 1 and 5 minutes after birth

nurse monitors the newborns body temperature and othervital signs until they stabilize


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Phychosocial changes

- the nurse promotes the parents and newborns need for close

physical contact.

- assess physical factors ( e.g fatique, hunger, and health ) andemotional factors ( e.g happiness and needs for affection and touch).

- bonding occur when parents and newborn elicit reciprocal and

complementary behavior.

- parental bonding behaviors include attentiveness and physicalcontact

- newborn bonding behavior involves maintenance of contact with the

parent.


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Health Risk

- nasopharyngeal and oropharyngeal suction are susceptible to heat

loss and cold stress

- hypothermia see measures to prevent cold stress- prevention of infection : good hand-washing techniques, wearing

gloves when touching mucous membranes and when drawing blood

- prophylactic treatment againts neisseria gonotthoeae and other

infections, which can be transmitted during passage through aninfected vaginal canal.

- Vit K is administeres SD shortly after birth .

- the stump of the moist umbilical cord.


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Measures to prevent cold stress

Mechanism of heat

loss

Nursing Intervention

Evaporation Immediately dry newborn after delivery. Wrap in blanket.

Delay first bath until temperature and other vital signs are

stable

Conduction Warm objects that have direct contact with newborn. Covers

newborns head

Convection Prevent unnecessary exposure to cold

Radiation Use radiant warmer until temperature stabilizes. Avoid cold

drafts

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