Estrogen contraception may exacerbate seizure frequency. (Survy of 93 Women With Epilepsy).

SEATTLE -- One in five women with epilepsy could experience an increase in the frequency of their seizures after initiating estrogen-containing contraception, according to a survey of 93 epilepsy patients who had used hormonal contraception.

"The number of women in our survey is reasonably high. But still you have to take the findings with a fairly big pinch of salt. It was not a controlled study," Dr. Pavel Klein of the department of neurology at Georgetown University, Washington, D.C., said in an interview.

Seizures were not increased among those women who used long-term progesterone contraceptive methods such as Depo-Provera or Norplant, suggesting that those forms of birth control might be a better option for women with epilepsy, Dr. Klein said at the annual meeting of the American Epilepsy Society.

It has been known since the 1950s that estrogen can exacerbate seizure activity and that progesterone may have a mediating effect, but this relationship had been seen only in animal studies and a few anecdotal reports of isolated cases. In general practice the belief has tended to be that estrogen-containing contraceptives did not exacerbate seizures, he said.

The researchers interviewed 182 consecutively seen women with epilepsy between the ages of 14 and 55. ...