Maternal Physiology

Question 1

Total Body Water Metabolism

Answer 1

6.5 L -> 8.5 L State of chronic volume overload (active Na and water retention (>))

Question 2

Osmoregulation

Answer 2

Serum Na usually drops 3-4 because greater increase in water retention Activation 4-5x of renin, angiotensin, aldosterone (2x) ANP & BNP elevation

Question 3

CV Changes

Answer 3

Plasma volume increases by 50% RBC mass up 20-30% - dilutional anemia Decreased SVR (progesterone) CO up by 40% (SV mainly) - more to renal, breast, skin, uterus S3 common Increase in sinus tachy

Question 4

Labor CV changes

Answer 4

p

Question 5

Pulmonary Changes

Answer 5

TV increases RR same Progesterone = sensitive to CO2 = hyperventilation PaO2 up (normal = 104-108) pH up

Question 6

Respiratory Volume Changes

Answer 6

Up TV (so minute ventilation RRxTV is increase) normal FVC, down ERV

Question 7

Pregnancy Gas Values

Answer 7

t

Question 8

Renal Changes

Answer 8

Relative hydronephrosis (more right side) from compression and progesterone vasodilation Pyelonephritis common and can cause problems Increased GFR = less BUN/Cr Can worsen underlying disease permanently

Question 9

Hematology Changes

Answer 9

Platelets also diluted

Question 10

GI changes

Answer 10

Only 200/300 increase in calories need Hyperemesis (4-16 wks) Down tone and motility (progesterone) Increased reflux Early satiety More diarrhea and constipation More gallstones

Question 11

Skin Changes

Answer 11

Increase in pigmentation Melasma From hCG, fairly permanent