Pregnancy Physiology Flashcards
outline the stages an embryo goes through after fertilisation
ovulation - fertilisation - cleavage - morula - blastocyst - implantation
what is the name of the clump of cells that is implanted after fertilisation
blastocyst
where does fertilisation usually occur
ampulla of the fallopian tube
on what days after fertilisation does the blastocyst move to the uterus
days 3-5
on what days after fertilisation does the blastocyst implant onto the uterus lining
day 5-8
what do the inner and outer cells of the blastocyst become respectively
inner - embryo
outer - placenta
what 2 types of tissue is the placenta derived from
trophoblast tissue and decidual tissue (mucosal lining of the uterus)
maternal and foetal blood do not cross true/false
true - separated by connective tissue
which hormone signals for the corpus luteum to continue secreting progesterone
HCG
the foetal heart and placenta are functional by which week of pregnancy
5th
outline some of the main functions of the placenta
2 way gas exchange
water and electrolyte diffusion
glucose enters foetus through simplified transport
de-oxygenated blood returns to the mother via which vessel
uterine vein
oxygenated blood enters the foetus via which vessel
umbilical vein
what is the main function of HCG
prevents involution of the corpus luteum
what does the corpus luteum stimulate
progesterone release
what are the main functions of HCS
growth hormone like effects
breast development
reduces insulin sensitivity in the mother allowing more glucose for the foetus
outline 3 functions of progesterone
development of decidual cells
decreases uterine contractility
prepares for lactation
outline 3 functions of oestrgoen
enlargement of uterus
breast development
relaxation of ligaments/increases uterine contractility
how does cardiac output change in response to pregnancy
increases due to uteroplacental circulation demands
why does CO decrease again roughly 8 weeks before term
due to uterus compressing on the vena cava
does plasma volume increase or decrease in pregnancy
decrease
what does the change in plasma volume and erythropoiesis mean for Hb concentration in pregnancy
erythropoiesis increases in pregnancy therefore Hb concentration decreases by dilution which in turn decreases plasma viscosity
does GFR and renal plasma volume increase or decrease in pregnancy
increase causing increased resorption of ions and water
what is the average weight gain during pregnancy
24 lbs
what is the additional calorie requirement in pregnancy
approximately 250-300 extra calories per day
which phase of pregnancy is sensitive to insulin and which is insensitive to insulin
1-20 weeks - sensitive to insulin
21-40 - insensitive to insulin, foetus also has increased metabolic demands
taking B vitamins helps with which process
erythropoiesis
taking folic acid helps prevent which defect
neural tube defects
why is vitamin K indicated before parturition
to prevent intracranial haemorrhage during birth
list some drugs that are concentrated/transmitted through breast milk
amiodarone carbimazapine nicotine heroin benzodiazepines
what effect on the neonate does amiodarone have
neonatal hypothyroidism
what effect on the neonate does cytotoxics in pregnancy have
bone marrow suppression
what effect on the neonate does benzodiazepines in pregnancy have
drowsiness
what does phenytoin in pregnancy increase the risk of
cleft lip/cleft palate
what does stillbestrol in pregnancy cause
vaginal adenocarcinoma as the child becomes older
what does sodium valproate in pregnancy increase the risk of
neural tube defects
by the end of the pregnancy, how does the oestrogen : progesterone ratio change
oestrogen increases to prepare for birth
which hormone stimulates contractility and excitability of the uterus
oxytocin
which hormone controls the growth of the lobular breast system
oestrogen
progesterone controls growth of the lobular system
which hormone promotes the production of breast milk
prolactin
describe the difference between foremilk and hindmilk
foremilk - protein rich
hindmilk - thinner, less protein for when the baby has been fed well
which hormone controls the let down reflex
oxytocin
describe the let down reflex
in response to stimuli such as a baby crying the brain senses that as hunger and promotes the let down of milk into the breast
which hormone is responsible for nausea and vomiting in early pregnancy
HCG
serum HCG levels double every __ in an early singleton pregnancy
48hours - if this is incorrect suspect a pathology
an unusually high HCG is suggestive of what condition
molar pregnancy
a falling HCG is suggestive of what condition
failing pregnancy such as miscarriage
a static or slow rising HCG is suggestive of what condition
ectopic pregnancy
how does blood pressure change in normal pregnancy
drops - lowest point is in second trimester
approx drops by 15mmHg from normal but returns in third trimester
what are the normal levels of Hb in pregnancy
first trimester Hb 110g/L
second and third trimester Hb 105g/L
