Folic acid slashes risk of congenital heart defects: reduction of 54%.(News)

ORLANDO, FLA. -- Women who are of childbearing potential have a powerful new incentive to consume a folic acid-containing daily multivitamin: evidence from a large prospective cohort study that this reduces by 54% their risk of having a baby with a ventricular septal or conotruncal defect.

"This is the first real preventive strategy to reduce the risk of congenital heart disease," Cynthia Morris, Ph.D., observed in presenting the groundbreaking study results at the annual scientific sessions of the American Heart Association.

She reported on a National Institutes of Health-sponsored study involving 899 consecutive women who presented for routine prenatal care and 985 others referred for fetal echocardiography. Participants initiated prenatal care at about 10 weeks' gestation and averaged a dozen prenatal visits.

All underwent a detailed interview assessing pregnancy history, lifestyle, and nutrition. They were followed until their babies were 1 year old to identify all congenital heart defects.

A total of 43 infants had a conotruncal defect and 39 had an isolated ventricular septal defect, 73% of which were diagnosed prenatally. Seven affected fetuses were later aborted or were stillborn. Two children who had a chromosome 22 deletion were excluded from the study.

In a multivariate logistic regression analysis adjusting for age, race, binge drinking, smoking, and other potential confounders, women who took a daily folate supplement during the first 6 weeks of pregnancy-the period of cardiogenesis were 54% less likely to have an affected baby, said Dr. Morris of Oregon Health Sciences University, Portland.

A dose-response effect was evident, with supplements containing larger amounts of folate being more protective.