Risk of Congenital Heart Defects Higher Among IVF Twins

The prevalence of congenital heart disease (CHD) among in vitro fertilization (IVF) pregnancies is similar to that of the general population, but there is an increased risk of CHD among twins resulting from IVF, according to research by Yale School of Medicine researchers.

Mert Ozan Bahtiyar, M.D., assistant professor in the Department of Obstetrics, Gynecology & Reproductive Sciences, will present the abstract today at the Society for Maternal-Fetal Medicine Annual Meeting in Dallas, Texas.

“We found that twin pregnancies conceived through IVF have a higher prevalence of CHD than singletons,” said Bahtiyar, noting the group found a three-fold increase. “IVF twins are usually fraternal, but past studies of identical twins also showed up to a 13-fold increase in congenital heart defects.”

Working with the Fetal Cardiovascular Center at Yale University and Yale-New Haven Hospital, a central referral center for the State of Connecticut, Bahtiyar and his colleagues examined almost 2,000 patients using fetal echocardiography. Among those patients, 250 women were pregnant as a result of in vitro fertilization. They did not have other medical problems that would require echocardiograms. Approximately 30 percent of these women had twin pregnancies.

Bahtiyar said that previous reports of increased CHD risk in pregnancies conceived via IVF might be due, in part, to a higher frequency of multiple pregnancies resulting from this form of conception. “The increased twinning seems to be the cause of the abnormality and not IVF per se.”

Bahtiyar and his team plan to do a larger study with more women.

“The next step is to explore why this is happening,” he said. “Knowing about the risk of these defects will help increase the likelihood of a child’s survival after birth.”

Other authors on the study included Antonette T. Dulay, Bevin P. Weeks, Alan H. Friedman and Joshua A. Copel.

A discussion on this topic is available on Yale University iTunes U, “Health and Medicine” section.