Heart Disease During Pregnancy

ByLara A. Friel, MD, PhD, University of Texas Health Medical School at Houston, McGovern Medical School
Reviewed/Revised Nov 2023
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Most women who have heart disease—including certain 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. Before becoming pregnant, such women should talk to their doctor to make sure their heart disease is being treated as effectively as possible.

For women with some types of heart disease, pregnancy is inadvisable because it increases the risk of death. These include

If women who have one of these disorders become pregnant, doctors advise them to terminate the pregnancy as early as possible.

Pregnancy requires the heart to work harder. Consequently, pregnancy may worsen heart disease or cause heart disease to cause symptoms for the first time. Usually, the risk of death (to the woman or fetus) is increased only when heart disease was severe before the woman became pregnant. However, depending on the type and severity of the heart disease, serious complications may develop. These complications include accumulation of fluid in the lungs (pulmonary edema), an abnormal heart rhythm, and stroke.

The risk of problems increases throughout pregnancy as demands on the heart increase. Pregnant women with heart disease may become unusually tired and may need to limit their activities. Rarely, women with severe heart disease are advised to have an abortion early in pregnancy. Risk is also increased during labor and delivery. After delivery, women with severe heart disease may not be out of danger for 6 months, depending on the type of heart disease.

Heart disease in pregnant women may affect the fetus. The fetus may be born prematurely. Women with certain 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 severe heart disease in a pregnant woman suddenly worsens, the fetus may die.

Peripartum cardiomyopathy

The heart’s walls (myocardium) may be damaged (called cardiomyopathy) late in pregnancy or after delivery. This time frame is called the peripartum period, and thus, this disorder is called peripartum cardiomyopathy. The cause is unknown.

The following factors increase the risk of peripartum cardiomyopathy:

  • Several prior pregnancies

  • 30 years of age or older

  • Carrying more than one fetus

  • Preeclampsia (a type of high blood pressure that occurs during 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.

Treatment of peripartum cardiomyopathy is similar to treatment of heart failure

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. Stenosis of the mitral valve can result in fluid accumulating in the lungs (pulmonary edema) and a rapid, irregular heart rhythm (atrial fibrillation

Women with severe aortic or mitral stenosis that causes symptoms are discouraged from becoming pregnant.

Women with mitral valve prolapse usually tolerate pregnancy well.

Treatment of Heart Disease During Pregnancy

  • Avoidance of certain medications during pregnancy

  • During labor, an epidural injection

Doctors advise pregnant women with heart disease to do the following:

  • Schedule frequent check-ups

  • Avoid gaining excess weight

  • Avoid stress

  • Get enough rest

Anemia, if it develops, is promptly treated.

Certain medications used to treat heart disease are not used during pregnancy. They include the following:

warfarin reduces the risk that blood clots will form in these valves. Such clots can be fatal.

During labor, pain is treated as needed. If women have severe heart disease, doctors may inject an anesthetic into the lower back—into the space between the spine and the outer layer of tissue covering the spinal cord (epidural space). This procedure is called an epidural injection. This anesthetic blocks sensation in the lower spinal cord, reducing the stress response to pain and the urge to push. The purpose is to reduce the strain on the heart. Pushing during labor strains the heart because it makes the heart work harder. Because these women cannot push, the baby may have to be delivered with forceps or a vacuum extractor.

An epidural injection should not be used if women have aortic stenosis. A local anesthetic or, if needed, a general anesthetic is used instead.

Women are monitored closely immediately after delivery and are checked periodically by a cardiologist for several weeks afterward.

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