But newer antiepileptic medications used during the first trimester carry no such risks, finds a new study published Monday in the Journal of the American Medical Association.
“Commonly, the message was, ‘you cannot have children,’” says Dr. Page Pennell, chair of the Professional Advisory Board for the Epilepsy Foundation. “So it really was an unfortunate situation when young women or even teenagers were told that their whole life-course was determined by the fact that they need an epilepsy medication.”
The second-generation of antiepileptic medications began appearing in the early 1990s, and are commonly prescribed to treat other conditions too, such as migraines and bipolar mood disorder.
Importantly, the study only measures the risks of birth defects – it does not measure other risks, such as miscarriages and learning disabilities.
“We have some pretty consistent findings between studies that show that some medications, for instance, Valproic acid, have a particularly high risk for children having a learning disability and possibly even autism spectrum disorder,” says Pennell. “But other medications can be quite safe and not have increased risks of learning problems in the child.”
One major limitation of the study findings is the grouping of antiepileptic drugs into just two broad categories, says Pennell. The study compares newer drugs with older drugs, but within and across those two categories, some drugs are safer than others.
For example, the antiepileptic drug topiramate is one of the second-generation drugs found to be safe by the study, but in March the FDA issued a stronger warning for the drug, saying that “there is positive evidence of human fetal risk based on human data.”
The researchers studied data from 837,795 live-born infants in Denmark using the country’s Medical Birth Registry and information on filled prescriptions from the Registry of Medicinal Product Statistics.