7.Physiologic changes in pregnancy (renal system, hormonal changes) Flashcards
what occurs to the GFR, BUN and creatinine during pregnancy?
GFR increases by 40-50% early in pregnancy and is maintained elevated until delivery (= hyperfiltration state)
BUN and Creatinine both decrease by about 25%
what is the normal Creatinine value in pregnancy?
0.4-0.8 mg/dL
not pregnant: 0.6 to 1.1 mg/dL
why is there a risk for UTI and renal stones during pregnancy?
due to Obstructive uropathy by the gravid uterus at the pelvic brim, and dilation of the ureter (physiological by progesterone)
*glucosuria in 50% of pregnancies
is Glucosuria a normal finding of pregnancy?
YES
seen in up to 50% of pregnant women; primarily due to decreased proximal tubular glucose absorption
how is Respiratory alkalosis of pregnancy compensated?
by increased HCO3- excretion (by up to 20%).
what occurs to the plasma sodium during pregnancy?
lowers by 4-5 mEq/L.
due to increase in GFR
even though there’s an increase in the RAAS –> increased levels of aldosterone–>increased sodium resorption
what is the role of hCG (human chorionic gonadotropin) for the first 8-10 weeks of pregnancy?
Maintains corpus luteum (and thus progesterone) by acting like LH
when is ↑ hCG?
multiform gestation, molar pregnancy, choriocarcinoma, and Down syndrome
when is ↓ hCG ?
in ectopic or failing pregnancy, Edward syndrome, and Patau syndrome
what is the main estrogen in pregnancy and what produces the most of it ?
estriol E3
the placenta
the ovaries contribute in a lesser degree
what is the role of estrogen in pregnancy?
- Increases uterine blood flow and prepares the breast for lactation.
- Up-regulates the expression of transport proteins and SHBG; also ↑ HDL, ↓ LDL.
what is the role of progesterone in pregnancy?
- Maintains pregnancy
- Acts as a smooth muscle relaxant with multiple effects on the CV, GI, GU, and biliary systems.
- Decreases myometrial excitability → decreased contraction frequency and intensity.
- Decreases prolactin action of the breast during pregnancy. Fall in progesterone after delivery releases the inhibition, resulting in lactation.
- Increases body temperature.
progesterone is produced by?
initially by the corpus luteum, then replaced by the placenta (after week 10)
Another name for Human placental lactogen (hPL) who produces this hormone?
Human chorionic somatomammotropin (hCS)
placenta
what is the role of hPL?
- important for ensuring constant nutrient supply to the fetus.
- Induces lipolysis with a concomitant increase in circulating free fatty acids.
- Acts as an insulin antagonist (along with various other placental hormones), thereby having a diabetogenic effect; leads to increased levels of insulin and protein synthesis.
