SATURDAY, Dec. 3 (HealthDay News) -- Seizures among women of childbearing age with epilepsy may worsen during menstruation or ovulation, researchers have found.

In the study, investigators at the Comprehensive Epilepsy Center at the University of California, Irvine, examined the trend of seizures associated with menstrual cycles (called "catamenial" seizures) among a group of women aged 19 to 50.

The study participants responded to a questionnaire about the worsening of their seizures during their menstrual cycle, and the researchers used these responses as well as the women's monthly seizure calendars to identify those with catamenial seizures.

Among the women with catamenial seizures, the investigators examined the type of epilepsy they had, the frequency of their seizures, their response to medications as well as neuroimaging findings and seizures during pregnancy, according to a news release from the American Epilepsy Society.

Two-thirds of the women with catamenial epilepsy had a diagnosis of partial epilepsy. The rest had primary generalized epilepsy. Meanwhile, about 75 percent of the women with catamenial epilepsy had medically refractory seizures -- which means they're resistant to treatment. The rate was twice that of their peers with epilepsy who did not have catamenial seizures.

A high percentage of women with catamenial epilepsy who had children reported having more seizures during pregnancy, according to the study authors, Avriel Linane and Mona Sazgar.

The study findings were slated to be presented Sunday at the annual meeting of the American Epilepsy Society in Baltimore. The data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The Epilepsy Foundation of America has more about women and epilepsy.