Endocrinology of pregnancy Flashcards
when does hCG start to occur?
starts 8 days after aovulation
what does hCG do?
informs corpus luteum to pump out as much progesterone and estrogen as posssible
where is hCG produces?
by trophoblast
whats the function of progesterone during pregnancy?
- maintains decidual lining
- used by fetal adrenal cortex as a substrate in the synthesis of cortisol and aldosterne.
- quiets uterine muscle activity by inhibiting prostaglandin production and myometrial responsiveness to oxytocin.
- contributes to mammary gland developement while also supressing lactation.
why can fetal adrenal cortex not produce aldosterone and cortisol?
b/c it lacks 3-b-HSD
how is estriol synthesised?
- cholesterol ( from fetal zone of adrenal cortex) –> progesterone–>DHEA-s ( will go to fetal liver)–> 16-OH-DHEAS–> placenta ( sulphate removed)–> estriol (E3) produced by armotase.
function of estrogen?
- stimulate continues growth of uterine muscles necessary for labor.
- stimulate prolactin
- developement of mammary gland ducts
when does fetal adrenal cortex become adult adrenl cortex?
2nd half of pregnancy
it utilizes placental progesterone ( from maternal cholesterol) to produce cortisol.
why is production of cortisal in fetus important?
b/c plays a major role in developement of surfactant, lungs, interstitial villi and closure of ductus arteriosus of the fetus.
name hormones that placenta produces?
- GnRH
- TRH
- GHRH
- somatostatin
- ACTH
- TSH
- CRH
function of CRH?
stimulates fetal pituritary to secreate ACTH causing fetal cortisol and DHEA production causing E2:P4 ratio to increase
positive feedback of CRH production?
amplifies CRH production.
whats the E2:P4 ratio before delivery?
its ratio increases, but estradiol is dominant due to
what local production does estrogen do?
local production of prostaglandins PGE2 and PGF2-a–> increase in [ca2+]ic–> uterine smooth m. contraction
what does oxytocin do and what stimulates it?
- stimulant of uterine contraction which is stimulated by cervix dilation.
