Pregnancy Flashcards
what is the chorionic membrane made up of
cytotrophoblast and syncytitrophoblast
which part of the trophoblast allows for implantation
syncytiotrophoblast as this contains specialised receptors to allow for initial contact and to enter the endometrium
when and where does implantation occur
day 6 on the superior, posterior uterine wall
what is an ectopic pregnancy
where implantation occurs anywhere other than the uterine body
where do ectopic pregnancies most commonly occur
Fallopian tubes
what is placenta praevia
where implantation occurs over the internal os
how many umbilical arteries are there and what do they carry
2 carrying deoxygenated blood from the foetus to the placenta
how many umbilical veins are there and what do they carry
1 carrying oxygenated blood from the placenta to the foetus
what is the decidua
the modified endometrium which controls the invasion of the embryo into the endometrium
what is the decidua like in pre-eclampsia
sub-optimal therefore doesn’t allow full implantation of the embryo
what cardiovascular changes are seen in a pregnant woman
varicose veins and oedema - due to increased IVC pressure from compression
bp may decrease slightly
hypertrophy of heart, heart murmur
what may cause a decrease in bp in pregnancy
progesterone causing vasodilation
what happens to calcium metabolism during pregnancy
placenta produces DHCC which increases calcium absorption to pass to the foetus to help bone development
what steroid hormones are produced by the placenta
oestrogen and progesterone
when does the placenta start producing steers hormones
about 11 weeks
how does inhibin prevent a further pregnancy
inhibits FSH so follicle maturation can’t occur
what affects does progesterone have
vasodilator
increases appetite
why is an increase in appetite advantageous in pregnancy
to increase fat stores to supply foetus when its more metabolically active and for use of fatty acids for respiration for the mother
what protein hormones does the placenta produce
hCG
hCS
hCT
hCC
what does hCG do
supports corpus leutum until placenta takes over hormone production
where is hCG produced
syncytiotrophoblast
what does hCS stand for
human chorionic somatomammotrophin
what does hCS do
decreases the mothers sensitivity to insulin so there is more glucose circulating in her blood so more glucose to diffuse across the placenta
what structures in the placenta allow for maximising exchange
villi in the cotyledons
what are cotyledons
areas where both maternal tissue and fatal villi are found and so where exchange occurs
what happens to the placenta membrane as the foetus grows
it gets thinner - decreasing the diffusion gradient
what do the cytotrophoblast do
develop into the syncytiotrophoblast is there are holes/gaps in this layer
how is passive immunity achieved through the placenta
IgG can diffuse through the placenta to supply the foetus
what is teratogenesis
when normal development of the fetus is altered
what are teratogens
agents which influence/alter normal development of the fetus
give some examples of teratogens
alcohol, thalidomide, warfarin, ACE inhibitors, smoking
when is the most sensitive period for the effect of teratogens
embryonic period (2-8 weeks)
what is a molar pregnancy
where there is overgrowth of the trophoblast and so implantation can go all the way through the uterus and it can spread into the blood
what is choriocarcinoma
malignancy of the chorionic membrane
what does gestational diabetes cause
an increase in glucose in the child
what effects will the child have due to gestational diabetes
larger
hyperplasia of B cells in pancreas sue to increase in insulin production
increase in glycogen stores in the liver
reparatory distress syndrome
why can babies born to mothers which gestational diabetes have respiratory distress syndrome
as they have a premature birth so didn’t have enough time to produce surfactant
why are babies born to mothers with gestational diabetes hypoglycaemic at birth
as they suddenly have their glucose supply dropped and it takes times for their feedback mechanisms to fix this as hey haven’t been needed before
what is physiological anaemia in pregnancy
where there is an increase in plasma volume but not RBC mass and so there is a decrease in the haematocrit
why does the plasma vol of blood increase but RBC mass does not in pregnancy
as the nutrients the baby needs are in the plasma where as they don’t have a big required for oxygen
what affects can the baby have if the mother has severe anaemia
underdeveloped, still birth, growth retardation
what causes pre-eclampsia
the embryo does not implant into the endometrium fully and so the needs to the foetus can’t be met - therefore the mother increases blood flow to the placenta to try and combat this
what signs/symptoms will a women with pre-eclampsia have
protein in the urine
high blood pressure
decrease in kidney and liver function
oedema (pitting)
what is eclampsia
life threatening seizures
what changes occur in the reflexes of a mother with pre-eclampsia
the increased blood flow causes more activity of the reflexes
what eye changes will occur in pre-eclampsia
double vision, blurry, blindness - due to ischamia to the back of the eyes
