What percentage increase in cardiac output occurs during pregnancy?

During pregnancy, there is a significant physiological change in a woman's body, particularly in the cardiovascular system. The correct answer is a 25% to 50% increase in cardiac output, which is attributed to multiple factors associated with pregnancy.

As the pregnancy progresses, the body requires increased blood flow to support the growing fetus, placenta, and maternal tissues. The heart pumps more blood due to several adaptations, including an increase in blood volume and alterations in vascular resistance. This increase in stroke volume, combined with a modest rise in heart rate, leads to the overall increase in cardiac output.

This increase is crucial as it ensures that adequate oxygen and nutrients reach the developing fetus while also meeting the metabolic demands of the mother. Understanding the range of 25% to 50% helps to appreciate the extent of cardiovascular changes that occur, emphasizing the need for careful monitoring of cardiovascular health during prenatal care.