Physiologic changes in pregnancy.

Pregnancy is associated with physiologic changes that affect virtually every organ system in the mother. These physiologic changes allow the parturient to support the growing uterus and fetus and to withstand labor and the postpartum course. Because the gravida may require surgery while pregnant, it is important to have an appreciation of these physiologic changes. These maternal adaptive responses have significant implications for anesthetic, operative, and perioperative management.