WEEK 12: 12.6 Pregnancy Flashcards
(12 cards)
How is metabolism affected in pregnancy?
It isn’t static, metabolism changes as pregnancy progresses
Mother initially anabolic —> catabolic by late pregnancy
What happens in early pregnancy to the mother’s metabolic changes?
Increased insulin production, normal/enhanced insulin sensitivity (adipocytes) —> energy storage
What happens in later pregnancy to the mother’s metabolic changes?
elevated insulin —> insulin resistance –> lipolysis –> hepatic glucose production —> maintain fetal nutrient supply
What happens to B cell mass in early pregnancy?
It increases, which allows increased insulin secretion from early pregnancy (to make up for reduced insulin sensitivity due to estrogen and progesterone)
What effect does increased insulin have on energy storage?
It promotes white adipose tissue fat storage
Why is there insulin resistance in late pregnancy?
to maintain maternal circulating glucose, to maintain fetal supply of glucose
this results in decreased insulin sensitivity
& increased basal hepatic glucose production via gluconeogenesis
What happens in regards to lipid metabolism in late pregnancy?
due to peripheral insulin resistance, glucose is not broken down for energy, hence there is increased lipolysis and increasing circulating fatty acids & glycerol for maternal energy and feto-placental supply
shift to fat oxidation as maternal energy source to spare glucose and amino acids (for fetus)
increased fat oxidation leads to ketones for fetal energy
How do progesterone and estrogen affect cardiac function?
progesterone stimulates maternal heart growth by stimulating growth and inhibiting apoptosis of cardiomyocytes
elevated estrogen may allow increased activation of stretch activated kinases to stimulate heart growth
Why does blood pressure fall in the first half of pregnancy ?
vascular resistance falls, arterial compliance increases during pregnancy, increasing blood vessel volume and reducing afterload on the heart.
vasodilation & arterial compliance are mediated by increased production of nitric oxide
elevated maternal circulating relaxin and estrogen conc. during pregnancy induces expression of NO in maternal blood vessels
Why is there a higher blood volume in pregnant women?
maternal plasma and extracellular fluid volume increases 45-50% during pregnancy, occupying greater vascular volumes created by the placenta through vasodilation and enabling perfusion of added vessels in the placenta, as well as greater blood flow to maternal tissues like kidneys
What happens to pregnant women as a result of increased blood volume?
- altered water balance from elevated aldosterone and cortisol in later pregnancy leads to more sodium and water retention
RAAS is upregulated by estrogen, increasing sodium absorption
osmostat set point changes so thirst increases at lower than usual osmolality
What clinical consequences can arise in pregnancy due to increased fluid volumes?
- increased fluid volume/hemodilution are normal
- oedema (excess fluid in tissues leads to swelling)
- increased connective tissue fluid can cause laxity/pain in some joints
