Which cardiovascular parameter increases by 60% during pregnancy?

During pregnancy, plasma volume is significantly increased, with estimates suggesting that it can rise by approximately 50-60%. This expansion is a crucial adaptation to support the growing fetus, enhance nutrient delivery, and accommodate the demands placed on the maternal body. Increased plasma volume leads to hemodilution, which helps to maintain adequate perfusion to maternal organs and the placenta.

While both blood volume and red cell mass do increase during pregnancy, the plasma volume is the primary component that expands most dramatically by 60%. Heart rate also tends to increase during pregnancy as a compensatory mechanism for the increased blood volume and metabolic demands, but the specific parameter that demonstrates a 60% increase is plasma volume. The changes in blood volume and red cell mass are important, but they do not reflect the same degree of percentage increase as plasma volume does. Thus, focusing on plasma volume provides the clearest insight into this significant cardiovascular adaptation during pregnancy.