Pregnancy and Heart Disease
by James B. Lam, M.D.
Fifty years ago, doctors regularly told women with heart disease to avoid pregnancy. That changed as more was learned about the changes a pregnant woman's body undergoes and now it is not unusual for women with heart disease to have a normal (albeit carefully monitored) pregnancy.
Pregnancy puts tremendous strains on the heart and circulatory system. By the time the baby is due, blood volume has increased by up to 50 percent, meaning the heart must beat faster and harder to move all that blood.
It is essential that women with heart disease discuss their illness with their doctors before becoming pregnant. While most women with heart disease can carry a baby to term under the care of a obstetrician and cardiologist, those with certain congenital heart diseases--cyanotic congenital heart disease, pulmonary hypertension, or severe aortic stenosis--are at high risk of losing their babies, their lives, or both.
It is also important to discuss with the doctor the possibility of passing on a congenital heart defect to the child. Between four and five percent of children born to women with significant congenital heart disease inherit the condition. With some disorders the rate can climb to 50 percent.
There are a range of precautions a doctor may advise for a pregnant woman with heart disease. They include a reduction in physical activity with frequent 20 to 30 minute rests in bed to minimize the heart's work load; always lying on the left side so that the uterus does not compress the vena cava--the large blood vessel in the lower body that brings blood back to the heart. A low-salt and sodium diet may be recommended and the mother-to-be may be told to avoid long, hot showers or tub baths that dilate blood vessels in the arms and legs and divert blood away from the developing baby.
In rare circumstances a woman develops heart muscle disease around the time of birth called peripartum dilated cardiomyopathy. "Peripartum" means "around the time of birth." Another name for this damage to the heart muscle tissues is congestive cardiomyopathy. The muscle becomes inflamed for no apparent reason--there is no bacterial or viral infection. If the woman is treated promptly and recovers from the disease, there is a very high risk it will recur if she becomes pregnant again. Although the cause of the disease is not known, researchers note that it is more common in black women than other women in the United States.
© 1999 Cardiovascular Institute of the South, printed with permission via Mediconsult.com, Inc.
