What’s a mother-to-be to do? That may be the question of the decade for women of childbearing age who have epilepsy. Do they risk having a seizure while pregnant? Or do they risk exposing their fetus to anti-epileptic medications?

“This is a critical issue,” says Michael Privitera, MD, Professor of Neurology and Director of the Epilepsy Center at the University of Cincinnati Neuroscience Institute. “On the one hand, if a woman with epilepsy stops taking medication, she risks having seizures, which can hurt the fetus. On the other hand, we know that most of the antiepileptic drugs cause problems for the fetus. But our knowledge of the effects is imprecise, and the evidence base from which to make informed decisions in individual cases is limited.” For 11 years Dr. Privitera has served as the local principal investigator for an ongoing multicenter study of the adverse effects of antiepileptic drugs on the children of women who take them during pregnancy. Dr. Privitera helped design the study, and the UC Epilepsy Center has thus far enrolled more patients than any other academic health center site.

Early findings from the study were profound: Children born to mothers who took anti-seizure medications known as valproate while pregnant may have impaired cognitive development.

The news was so significant that it appeared as the lead paper, “Cognitive function at 3 years of age after fetal exposure to antiepileptic drugs,” in the April 16, 2009 issue of the New England Journal of Medicine. And on June 30, 2011 the U.S. Food and Drug Administration followed up with a Drug Safety Communication that warned of the link between lower IQ and exposure in the womb to valproate sodium or related products.

The FDA stated that, “Valproate products are FDA-approved drugs to treat seizures, and manic or mixed episodes associated with bipolar disorder (manic-depressive disorder), and to prevent migraine headaches. They are also used off-label (for unapproved uses) for other conditions, particularly for other psychiatric conditions. Valproate products include: valproate sodium (Depacon), divalproex sodium (Depakote, Depakote CP, and Depakote ER), valproic acid (Depakene and Stavzor), and their generics.”

“The research found that even in the absence of obvious malformations like cleft palate or spina bifida, children born to mothers receiving valproate had statistically significant and clinically relevant reductions in IQ at age 3 compared to children born of mothers receiving other antiepileptic drugs,” Dr. Privitera says.

As of 2007, valproate was still the second most commonly used anti-epileptic medication in women of childbearing age in the United States. Last week’s FDA warning, Dr. Privitera notes, is likely to change the way physicians treat women of childbearing age who have epilepsy. “It is rare that a study has such broad impact on the field,” he adds.

At the Epilepsy Center, drug safety during pregnancy is an important part of treatment decisions, says David Ficker, MD, the center’s Associate Director and head of its New-Onset Seizure Clinic.  “When we see new patients who wish to have children, we always discuss risk,” Dr. Ficker says. “Ideally, we want to prescribe treatment that is optimal for both the short- and long-term. If a woman hopes to have children five years from now, we want to find a medication that will work today and that also will be safe for her baby.”

Still, the decisions for mothers and physicians are not always easy. Another anti-epileptic drug, carbamazepine, has been found to have an effect on the verbal abilities of children exposed in the womb.

“Ultimately, there is much more research to be done,” Dr. Privitera says. “Someday, we hope to have tools that will enable us to select the optimal medication for each individual patient.”

– Cindy Starr