What cardiovascular changes occur during pregnancy?

During pregnancy, one of the most significant cardiovascular changes is the increase in blood volume. This increase is crucial as it serves several purposes: it enhances nutrient delivery to the growing fetus, supports the expanded uteroplacental circulation, and helps accommodate the physiological changes that occur during pregnancy, such as the increase in metabolic demands.

The body generally experiences a rise in blood volume by approximately 40-50% above non-pregnant levels, which begins early in pregnancy and peaks around the second trimester. This increase helps to maintain adequate blood flow to both the mother and the developing fetus while also providing a buffer against blood loss during delivery.

This physiological adaptation is essential for the health of both the mother and the baby, providing the necessary support for fetal development and the increased demands placed on the mother's cardiovascular system. Other options do not accurately reflect the typical cardiovascular changes seen during pregnancy; for instance, the heart rate typically increases, body temperature generally remains stable or may slightly rise due to hormonal changes, and blood pressure often decreases in the first two trimesters but can vary widely during pregnancy.