Most women who have heart disorders—including heart valve disorders (such as mitral valve prolapse) and some birth defects of the heart—can safely give birth to healthy children, without any permanent ill effects on heart function or life span. However, women who have moderate or severe heart failure before pregnancy are at considerable risk of problems.
Pregnancy requires the heart to work harder. Consequently, pregnancy may worsen a heart disorder or cause a heart disorder to produce symptoms for the first time. Usually, serious problems, including death of the woman or fetus, occur only when a heart disorder is severe before the woman becomes pregnant. About 1% of women who have a severe heart disorder before becoming pregnant die as a result of the pregnancy, usually because of heart failure.
The risk of problems increases throughout pregnancy as demands on the heart increase. Pregnant women with a heart disorder may become unusually tired and may need to limit their activities. Rarely, women with a severe heart disorder are advised to have an abortion early in pregnancy. Risk is also increased during labor and delivery. After delivery, women with a severe heart disorder may not be out of danger for at least 6 months, depending on the type of heart disorder.
A heart disorder in pregnant women may affect the fetus. The fetus may be born prematurely. Women with birth defects of the heart are more likely to have children with similar birth defects. Ultrasonography can detect some of these defects before the fetus is born. If a severe heart disorder in a pregnant woman suddenly worsens, the fetus may die.
During labor, women who have a severe heart disorder may be given an epidural anesthetic. This anesthetic blocks sensation in the lower spinal cord and prevents women from pushing. Pushing during labor strains the heart because it increases the amount of blood returning to the heart. Because pushing is not possible, the baby may have to be delivered with forceps. However, an epidural anesthetic should not be used if women have aortic valve stenosis.
For women with some types of heart disorders, pregnancy is inadvisable because it greatly increases the risk of death. Primary pulmonary hypertension and Eisenmenger's syndrome are examples. If women who have one of these disorders become pregnant, doctors advise them to terminate the pregnancy as early as possible.
The heart's walls may be damaged late in pregnancy or after delivery, causing peripartum cardiomyopathy. The cause is unknown. This disorder tends to occur in women who have had several pregnancies, who are older, who are carrying twins, or who have preeclampsia. In some women, heart function does not return to normal after pregnancy. Peripartum cardiomyopathy tends to occur in subsequent pregnancies, particularly if heart function has not returned to normal. Thus, women who have had this disorder are often discouraged from becoming pregnant again.
Peripartum cardiomyopathy can result in heart failure (see Heart Failure), which is treated as usual except that angiotensin-converting enzyme (ACE) inhibitors and aldosterone antagonists (spironolactone and eplerenone) are not used.
Heart valve disorders:
Ideally, heart valve disorders are diagnosed and treated before the women become pregnant. Doctors often recommend surgical treatment for women with severe disorders.
The valves most often affected in pregnant women are the aortic and mitral valves. Disorders that cause the opening of a heart valve to narrow (stenosis) are particularly risky.
Women with mitral valve prolapse usually tolerate pregnancy well.
Last full review/revision December 2008 by Sean C. Blackwell, MD