THURSDAY, Nov. 29 (HealthDay News) -- Having doctors monitor blood levels of the drug lamotrigine in pregnant women with epilepsy can help reduce the number of seizures they experience, U.S. research shows.

Lamotrigine, an epilepsy drug, is taken by pregnant women with epilepsy because of its relatively mild risk of causing birth defects. However, the drug has also been linked to increased seizure activity in 75 percent of pregnancies, according to background information in the study.

This study, reported in the Nov. 28 online issue of Neurology, found that monitoring levels of lamotrigine in the blood helps reduce overall seizure activity associated with the drug. It also helps improve the overall health of mother and fetus, the researchers say.

"This is important data considering current treatment guidelines do not address how to dose epilepsy drugs once women become pregnant," study author Dr. Page B. Pennell, of the Emory University School of Medicine in Atlanta, said in a prepared statement.

The study included 53 women taking lamotrigine who underwent drug monitoring every one to three months during their pregnancies. Drug doses were adjusted depending on lamotrigine levels in the blood. The goal was to maintain each woman's target lamotrigine level based on pre-pregnancy information.

Among the women in the study, 39 percent had increased seizure activity during pregnancy, 33 percent had reduced seizure activity, and 28 percent had no change. The health of their babies was similar to that of babies born to women without epilepsy.

"These rates are more consistent with what's been reported for pregnant women with epilepsy using other medications, and show the effectiveness of drug monitoring," Pennell said. "Our findings provide a foundation for treatment guidelines to prevent increased seizure frequency and ultimately improve the health of the mother and fetus."

More information

The American Academy of Family Physicians has more about epilepsy and pregnancy.