Postpartum cardiac output is most accurately described as which of the following?

• A. Cardiac output remains unchanged
• B. Cardiac output decreases with tachycardia
• C. Cardiac output increases for about 48 hours
• D. Cardiac output decreases and heart rate decreases

Answer: (C)

In the postpartum period, the heart pumps more because the body shifts a large volume of blood back into circulation after delivery (autotransfusion) and the circulating volume from pregnancy remains high. This increases venous return to the heart, stretches the ventricles, and raises stroke volume, so cardiac output rises. This elevated output typically lasts about 24 to 48 hours after delivery before returning toward pre-pregnant levels over the next days to weeks as the cardiovascular system rebalances.

So the statement that cardiac output increases for about 48 hours postpartum matches what actually happens. It isn’t unchanged, it isn’t decreased, and a decrease with tachycardia isn’t consistent with the typical postpartum hemodynamic pattern, where CO remains elevated despite any accompanying tachycardia.