physiology in pregnancy

Question 1

changes to the cardiovascular system during pregnancy

Answer 1

• significant changes in early first semester

increased circulating blood volume
systemic vascular resistance falls 20-32 weeks
increased blood flow
increased cardiac output
increased HR
in supine position (25% reduction CO)
increased O2 consumption

Question 2

what are changes in cardiovascular system intrapartum

Answer 2

autotransfusion of contractions
pain - increased catecholamines
CO increase by 10% and by 80% in 1st post delivery hr

Question 3

what are changes in cardiovascular system postpartum

Answer 3

return to normal by 3 months
blood volume decreases by 10% 3 days post delivery
SVR increase over first 2 weeks to above 30% above delivery levels
HR returns to pre pregnancy over 2 weeks
CO increases by up to 80% 1st hr post delivery then continues to fall over next 24 weeks

Question 4

what are respiratory changes during pregnancy

Answer 4

increase O2 demand 20%
40-50% increase in minute ventilation
increased RR
increased TV
decreased FRC
PEFR and FEV1 unchanged
PCO2 low
acid base balance
O2Hg dissociation curve

Question 5

what are renal changes in pregnancy

Answer 5

dilation of urinary collection system more pronounced on right
increased renal plasma flow 60-80% by end of second trimester
GFR increase and creatinine clearance increases by up to 50%
protein excretion increased
microscopic haematuria may be present
80% women develop oedema
glycosuria common
rate increase with increasing gestation
urea decrease creatinine decrease
UTIs

Question 6

what are haematological changes during pregnancy

Answer 6

plasma volume increases
lower platelet count
increase need 2-3 times for iron
10-20 fold increase in folate requirements
bcc increases
hypoercoagulable