Epilepsy Drug May Boost Birth Defect Risk

By Steven Reinberg
HealthDay Reporter
Monday, July 21, 2008; 5:00 PM

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MONDAY, July 21 (HealthDay News) -- Pregnant women who use the epilepsy drug topiramate alone or in combination with other epilepsy drugs may be increasing their risk of birth defects, British researchers report.

Topiramate (brand name Topamax) is a common anti-seizure medication used by many with epilepsy. It's also used to treat migraine headaches. Many similar drugs also increase the risk of birth defects, but until this report, the link between birth defects and topiramate had not been well studied.

"More research needs to be done to confirm these results, especially since it was a small study," lead researcher John Craig, of the Royal Group of Hospitals in Belfast, Northern Ireland, said in a news release from the American Academy of Neurology. "But these results should also get the attention of women with migraine and their doctors, since topiramate is also used for preventing migraine, which is an even more common condition that also occurs frequently in women of childbearing age."

The report is published in the July 22 issue of the journal Neurology.

For the study, the researchers collected data on women who became pregnant while taking topiramate alone or in combination with other epilepsy drugs.

Craig's team found that of the 178 babies born, 16 (4.8 percent) suffered from major birth defects. Among the babies with birth defects, three of the mothers were taking topiramate exclusively, while 13 were taking topiramate plus other epilepsy drugs.

Four of the babies had cleft palettes or cleft lips. That's a rate 11 times higher than one would expect among women not taking the drug, the researchers said.

Among male babies, four had genital defects, with two classified as "major defects." That's a rate 14 times higher than normal, the researchers reported.

The incidence of birth defects among women taking topiramate was higher than the rate of birth defects in the general population, which is about 1 percent to 2.5 percent. And there were more birth defects among women taking topiramate along with the epilepsy drug valproate, compared with women taking topiramate and another epilepsy drug.