Physiological Changes in Pregnancy
Highest cardiac output in pregnancy is: (AIIMS May 2012)
a. Cardiac output increases by 40% during pregnancy, 50% during each uterine contraction in labor, and 80% immediately postpartum (as the uterus contracts, blood from uterus is pushed back into the maternal system, also known as “autotransfusion”).
b. Therefore the risk of cardiac failure is maximum in the immediate postpartum period (followed by intrapartum). To avoid this, diuretics should be given after placental delivery to heart disease patients.
(Ref: Williams 22nd ed pg 1020)