Folic acid not protective in women on AEDs: users of antiepileptics did not see a reduction in major congenital anomalies.(Registry Data)

PHILADELPHIA -- Use of folic acid at the time of conception was not associated with a statistically significant reduction in the risk of having an infant with a major congenital anomaly in women taking antiepileptic drugs.

That finding emerged from a study of data compiled in the Antiepileptic Drug (AED) Pregnancy Registry at Massachusetts General Hospital, Charlestown. The study was presented at the annual meeting of the Teratology Society.

"This finding is, unfortunately, disappointing," Dr. Lewis B. Holmes, director of the registry, said in an interview. "A lot of physicians and patients have been hoping that, if you take folic acid at the time of conception, then you reduce your risk of malformation. These data do not support that hope" in this population.

An estimated 1 in 200 pregnant women in the United States takes an anticonvulsant drug, either for epilepsy or for various mood disorders. "It is a common exposure," said Dr. Holmes, professor of pediatrics at Harvard Medical School, Boston.

In the study, the effect of periconceptional folic acid on the risk for major congenital malformations was assessed prospectively in 505 pregnant women who were exposed to monotherapy with AEDs.

Among the 505 infants born to the study participants, 34 (6.7%) had a major malformation. Of the 34 mothers of these infants, 24 (70.6%) took periconceptional folic acid and 10 (29.4%) did not. Of the 471 mothers of the nonmalformed infants, 309 (65.6%) took the supplement. "The percentage of the women in the two groups--those with malformed children and those with nonmalformed children--who were taking folic acid at the time of conception was the same in both groups. In other words, the supplement was not protective," said Dr. Holmes.

The AED Pregnancy Registry at Massachusetts General Hospital is a national service that was ...