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Flashcards in Maternal Adaptations To Pregnancy Deck (10)

What changes happen to the urinary system during pregnancy?

Increased GFR (~55%) due to progesterone effects on the renal vessels and increased blood volume
Decrease functional renal reserve
Urinary stasis - progesterone relaxes smooth muscle in the ureters. Increased risk of UTI and pyelonephritis


What changes happen to the thyroid gland during pregnancy?

Increased production of TBG by the liver to increase t3 and t4 levels in the blood
Increased t3 and t4 production due to hCG acting on the thyroid
Decreased TSH levels due to the negative feedback


What changes happen to lipid metabolism during pregnancy?

Increase in lipolysis in t2
Increase in plasma conc of free fatty acids (they preview a substrate from maternal metabolism, leaving the glucose for the foetus, increased risk of ketoacidosis)
Essential fatty acids can cross the placenta


What changes happen to the GI tract during pregnancy?

Organs become displaced n.b. Appendix rlq -> ruq as the uterus becomes enlarged
Progesterone causes relaxation of smooth muscle, decreased bowel movements and emptying, stasis of biliary tact, chemical change of bile salt components (increased risk of stones), increased risk of pancreatitis (due to hyperlipidaemia and stones)


What changes happen to the cardiovascular system during pregnancy?

Increase in blood volume
( increased co, SV and hr)
Decrease in BP in t1 & t2 due to progesterone (decrease SVR) and placental in parallel circulation
T3 - BP relatively normal, aortocaval compression by gravid uterus


What changes happen to the immune system during pregnancy?

Non-specific suppression of the local immune system at the maternofoetal interface
N.b. Transfer of autoimmune autoimmune antibodies and anti-D antigens


What drives the changes in carbohydrate metabolism during pregnancy?

Appetite is stimulated by progesterone in the first half of pregnancy and glucose is diverted in to fat synthesis. Oestrogen stimulates an increase in prolactin and generates a maternal resistance to insulin. This decreases utilisation of maternal glucose, which increases gluconeogenesis to maximise the availability of glucose to the foetus


What happens in supine postural hypotensive syndrome?

The enlargement of the uterus can compress the IVC, preventing venous return from the lower limb, therefore reducing filling of the heart and cardiac output. It is worse when lying down due to the increased pressure on the IVC. When lying down, it can be relieved by tilting to the left


What are two long-term sequalae of chronic venous distension?

Varicose veins, haemorrhoids


What changes happen to the respiratory system during pregnancy?

Upward displacement of the diaphragm
Increase in A-P & transverse diameter of the thorax
Decreased functional residual capacity
Increased ventilation rate (hyperventilation driven by progesterone and increased production of carbon dioxide)
Increased tidal volume