Pregnant women with congenital heart disease may have low complication risks during delivery

However, such women were more likely to undergo cesarean section and remain in the hospital longer, researchers said.

"We are pleased to find the risk of complications are not as high as expected in women with congenital heart disease," said Robert M. Hayward, M.D., lead study author and a cardiac electrophysiology fellow of the University of California in San Francisco. "While we don't know why these women have longer hospital stays, it's possible their doctors are keeping them admitted for extra observation."

Previous research has found that childbirth is a time of increased risk for complications in women with congenital heart disease, but little is known about what those cardiovascular risks might be.

Congenital heart disease occurs when there is a problem with the structure of the heart at birth. Congenital heart defects affects about 8 of every 1,000 infants born -- about 32,000 infants each year in the United States. Today, there are more than 1 million Americans living with congenital heart disease. Improvements in the treatment of congenital heart disease has helped more women reach childbearing age. -

Researchers analyzed medical records of more than 2.7 million women who gave birth in California. Among this group, 3,218 women had non-complex congenital heart disease and 248 women had complex congenital heart disease, whose conditions were more advanced and had likely warranted surgical treatment during early childhood.

Researchers found:

• Reports of heart failure, arrhythmias and cardiac arrest were low for all three groups of women.
• In-hospital death rates were not significantly higher for women with complex congenital heart disease
• 47 percent of women with complex congenital heart disease underwent cesarean section compared to 40 percent of women with non-complex congenital heart disease and 33 percent of women without congenital heart disease.
• Women with complex congenital heart disease remained in the hospital on average 5 days, compared with women with non-complex congenital heart disease (3.4 days) and women without congenital heart disease (2.5 days).
• A history of congestive heart failure was more common in women with complex congenital heart disease (8.1 percent) versus 2.6 percent of women with non-complex congenital heart disease and 0.08 percent in women without congenital heart disease.

Hayward cautions that their study offers only a snapshot in time and does not address the maternal health of those with congenital heart disease during pregnancy or postpartum, nor does it look at fetal health during pregnancy.

"The data allows us to see associations, but it does not suggest any cause and effect," Hayward said. "We'd like to look at the period after delivery to see if there were any new admissions, heart failure or other complications to develop a better understanding of the health needs of maternal patients with congenital heart disease."