Final answer:
During pregnancy, the mother's blood volume increases by about 30%, helping to fulfill the growing fetus's needs for nourishment and waste removal.
Step-by-step explanation:
The blood volume of the mother increases by approximately 30% during pregnancy. This increase is critical for meeting the demands of fetal nourishment and waste removal. As the pregnancy progresses, changes occur in the circulatory and respiratory systems to support the growing fetus. The enhanced blood volume assists significantly in the transport of nutrients and oxygen to the fetus and the removal of wastes. Furthermore, other physiological adjustments, such as the increase in pulse and blood pressure, accommodate the expanding uterine size and changes in venous return, which may lead to varicose veins or hemorrhoids in many pregnant women.