Women who are diagnosed with epilepsy may be at a higher infertility risk, according to a study published in the journal Neurology.

Over the course of 10 years, a team of researchers monitored the infertility rate among a total of 375 women with an average age of 26 years. Throughout the trial, 62 percent of the participants had become pregnant, while 38 percent were infertile.

Of the women, 7 percent of those who didn’t use epilepsy medications were infertile. However, 32 percent of women using one drug, 41 percent who were taking two and 60 percent of patients taking three or more drugs were unable to have children.

Furthermore, the investigators discovered that women who were prescribed three or more medications to treat epilepsy were 18 times more likely to become infertile.

Alison M. Pack, a physician from Columbia University, stated that “based on these findings, women with epilepsy should be counseled about the potential risk of infertility and referred for an evaluation if they have not conceived within two years.”

Approximately 12 percent of women in the U.S. are infertile, according to the Centers for Disease Control and Prevention.