Question

Of the following statements most accurately describes the physiological changes that occur in the blood system during a normal pregnancy?

A. Blood plasma volume increases by 45% and red cell mass increases by 55%.
B. Blood plasma volume decreases by 45% and red cell mass decreases by 25%.
C. Blood plasma volume increases by 40-50% and red cell mass increases by 25%.
D. Blood plasma volume increases by 75% and red cell mass increases by 50%.
E. Blood plasma volume increases by 25% and red cell mass increases by 45%.

Answer 1

The most accurate description of physiological changes in the blood system during a normal pregnancy is that blood plasma volume increases by 40-50% and red cell mass increases by 25%.

During a normal pregnancy, there are significant changes in a woman's circulatory system.

One of the most notable changes is in the blood volume.

Blood plasma volume increases by approximately 40-50% while the red cell mass typically increases by about 25%. This expansion in blood plasma volume aids in meeting the heightened demands for fetal nourishment and waste removal.

It is also observed that there is a moderate rise in both the pulse rate and blood pressure during pregnancy. Additionally, the increased blood volume plays a role in the development of varicose veins or hemorrhoids, as the growing uterus exerts pressure on pelvic blood vessels, affecting venous return from the legs and pelvic region.

Considering the options provided and the reference information, option C, stating that 'Blood plasma volume increases by 40-50% and red cell mass increases by 25%', most accurately reflects the physiological changes in the blood system during a normal pregnancy.