Module 2: Pregnancy Flashcards
first phase in first trimester
embryonic phase
phase of the 2nd and 3rd tri
fetal phase
embryonic tissues
ectoderm, mesoderm, endoderm
ectoderm
outer layer formed in 2nd week
mesoderm
middle layer formed in third week
endoderm
inner layer formed in second week
ectoderm forms the…
spinal cord
mesoderm forms the…
heart
endoderm forms the…
bladder and urethra
chorion
precursor to placenta
amnion
precursor to amniotic sac
what 3 things occur during the first 3 weeks of pregnancy?
- embryo implants into endometrium
- foetal membranes become chorion and amnion
- placental function begins
fetal phase is characterised by
rapid growth in the size of the fetus
what does the fetus look like at the end of the 2nd trimester?
resembles a small baby with wrinkled, red and transparent skin. layer of vernix caseosa and lanugo
vernix caseosa
white cheesy substance covering the baby’s skin
lanuga
fine hair covering baby
when is fetal movement felt?
17-20 wks
size of baby at end of 2nd tri
50cm, 3.2-3.4kg
during pregnancy, the mother’s blood flow is increased by what?
1/3
what two factors increase (oxygen)
cardiac output and respiratory rate
the heartbeat is audible by fetoscope at?
20wks
what b vitamin helps prevent neural tube defects?
folic acid
fetal feces
not normally excreted until after birth, formed in intestine after swallowing amniotic fluid
poor oxygenation in the third trimester can result in ?
relaxation of baby’s anal sphincter leading to feces in the amniotic fluid, indicating fetal distress
when is urine excreted in the amniotic fluid?
when kidneys mature around 16-20 weeks
what can disturb the baby’s temperature?
spas, saunas, illness, leading to birth defects
what are teratogens?
agents that are harmful to the baby
smoking, drugs and alcohol can cause?
preterm labour, miscarriage, low birth weight, SIDS, learning disorders and birth defects
the uterus changes from being the size of the fist to filling the entire pelvic cavity by how many weeks?
16
as the pregnancy progresses, how does the mother’s anatomy change?
abdominal organs press against the diaphragm, pressure on the thoracic cavity causes the ribs to flare and the thorax to widen
what is lordosis?
accentuated lumbar curvature due to increased weight in the abdomen
relaxin
hormone produced by the uterus to prepare the birth canal for labour by relaxing the pelvic ligaments and pubic symphysis
gastrointestinal physiological changes
nausea, heartburn, constipation
why do pregnant women experience nausea?
as their body systems adjust to elevated levels of progesterone and estrogen
why do pregnant women experience heartburn?
displacement of esophagus, crowding of the stomach > reflux of stomach acid into esophagus
why do pregnant women experience constipation?
reduced motility in the digestive tract
urinary system
kidneys produce more urine to dispose/process of fetal metabolic wastes
nasal mucosa
becomes swollen in congested due to estrogen > causes stuffiness and nose bleeds
dyspnea in pregnancy
difficult breathing due to decline in residual volume
what is residual volume
air remaining in the lungs after maximum expiration
the most dramatic changes during pregnancy occur in what system?
cardiovascular
what happens to water, blood volume and pressure?
they increase
what does blood volume during pregnancy increase by and what does this prevent?
25-40%
blood loss during birth
cardiac output is increased by what due to BP and HR
20-40%
what does increased cardiac output help to do?
propel more blood around the body
why might a pregnant woman experience varicose veins or swollen ankles/feet?
venous return from lower limbs reduced due to pressure on pelvic blood vessels
childbirth is also called?
parturition
what happens in the blood during the last few weeks of pregnancy?
estrogens reach their highest levels
the increase in estrogen during the last few weeks of pregnancy results in what?
oxytocin receptors formed in the myometrium > braxton hicks contractions
which two chemical signals cause real contractions?
oxytocin produced stimulates release of prostaglandins
emotional and physical stresses in the final weeks of pregnancy cause what?
activation of the hypothalamus signalling release of oxytocin by the posterior pituitary
positive feedback mechanism of the hypothalamus
stronger contractions cause release of more oxytocin, causing even more vigorous contractions
antiprostaglandin drugs such as ____ will do what?
aspirin and ibuprofen
inhibit labour as both are needed for labour to initiate
4 stages of labour
dilation, expulsion, placental, postnatal
dilation stage of labour
time from the start of true contractions until the cervix is fully dilated
how long does dilation usually last?
6-12+ hours
what occurs with contractions during dilation?
each contraction forces the infant’s head against the cervix, causing it to efface and dilate
expulsion stage of labour
period from full dilation to delivery
how long does the expulsion stage take?
50 minutes in a first birth, 20 minutes in subsequent births but as long as 2 hours
head first position
vertex
when is the placenta delivered
within 15 minutes of the birth
what may be administered to ease the delivery of the placenta?
synthetic oxytocin
postnatal period
1-2 hours after birth
anatomy of sperm
head, acrosome, midbody, tail
which hormone causes ovulation
lutenising hormone (LH)
FSH (produced by and targeting what)
follicle stimulating hormone produced by anterior pituitary targeting the ovaries and testes
lutenising hormone
anterior pituitary targeting ovaries and testes
health promotion in pregnancy allows women to?
make informed health decisions affecting her pregnancy outcome
3 important nutrients during pregnancy
folate, iron, calcium
perinatal mental health
mental health during pregnancy and for the first year after irth
stats of antenatal depression
1/10
antenatal depression
depression during pregnancy
postnatal depression stats
1/6 women 1/10 men
baby blues
affecting 80% of new mothers, experienced 3-5 days post birth and lasting for a few days
which screening is used for antenatal and postnatal depression?
edinburgh postnatal depression scale
treatment for postnatal depression
psychological therapy, medication, hospital admission
stat of maternal rescusitation
1 in 30,000
Where is relaxin produced?
Ovary, placenta, breast, prostate
What does relaxin target?
Smooth muscle, connective and cardiac tissue cells
When is relaxin released?
During ovulation and throughout pregnancy
What effect does relaxin have on sperm?
It increases their mobility
Where is oxytocin produced?
Hypothalamus
Which organs does oxytocin target?
Uterus and breast tissue
What does oxytocin do?
Cause uterine contractions and helps with lactation
What produces prolactin?
Anterior pituitary
What does prolactin target?
Breast tissue
What kind of hormone is prolactin and what does it stimulate?
Protein hormone stimulating milk production
What does FSH stimulate
Production of ova and sperm
