Heart disease as a complication of pregnancy; with emphasis on indications for recommending therapeutic abortion or avoidance of conception.

Mere diagnosis of a valvular heart lesion without circulatory incapacity is inconsequential in considering the prognosis for a pregnant woman.There are grave dangers of heart failure during pregnancy, labor or the postpartum period in women who have had congestive failure prior to pregnancy or during a previous pregnancy and delivery. Decisions as to whether or not to recommend avoidance of pregnancy or therapeutic abortion should depend not alone upon the prospect of death during gestation or at the time of delivery, but also upon the possibility of increased impairment of heart function and physical incapacity of the mother in the postpartum period. Because of the extensive surgical procedure there are few indications for interrupting pregnancy after the third lunar month; and because the major circulatory loads do not increase after the eighth month, rarely should labor be prematurely induced after that time.The exertion of labor, although generally inconsequential, in some cases may produce sustained oxygen debt. In cases in which labor in a previous pregnancy has been accompanied by heart failure, cesarean section should be considered as a means of lessening the possibility of serious failure or death, although this is not a frequent consideration. In the resemblance of circulatory changes that occur, during delivery and immediately postpartum, to those changes produced by the closure of an arteriovenous shunt or patent ductus arteriosus, lies a suggestion as to some of the causative factors in heart failure during or soon after delivery. Probably of great importance is the decrease in blood volume and hemoconcentration at delivery followed by the return of water to the circulatory system, with consequent transient increase in blood volume, in the postpartum period. Additionally, the rise of venous pressure after use of oxytocic drugs suggests that rapid infusion of blood from an engorged uterus may cause an abrupt and perhaps poorly tolerated hypervolemia. Death by heart failure in pregnancy and the puerperium has become extremely rare in recent years due to the frequent observations, meticulous diagnosis of impending failure and improved care of cardiac patients jointly by the obstetrician and the internist. In addition to digitalis therapy and sodium restriction, patients exhibiting evidence of impending heart failure may require bed rest through the entire third trimester of pregnancy. Oxygen should be administered during labor in such patients and anoxia guarded against during anesthesia.