Pregnant women who and their physicians often face a difficult dilemma—whether to treat a woman’s pre-existing disease or condition with prescription drugs, or avoid medication all together. Either choice can create health risks for the mother and the baby.
For pregnant women with epilepsy, the problem is especially difficult. If a pregnant woman has an epileptic seizure, the seizure can cause damage to her fetus. However, prescription drugs used to prevent seizures can carry an increased risk of birth defects. These risks have been studied extensively for older drugs, but little information is available to assess the risks associated with newer anti-epilepsy medications. Current professional guidelines recommend that pregnant women with epilepsy continue taking anti-seizure medication unless they have not had a seizure in more than 2 years.
Scientists supported by the Developmental Biology and Structural Variations Branch assessed whether pregnant women who took topiramate, a prescription drug used to prevent seizures, were at increased risk of having babies with cleft lip. The researchers used information from two different datasets, analyzing each dataset separately and then combining the two. They found that women who took topiramate during the first trimester of pregnancy were more likely to have babies with cleft lip, with or without cleft palate.
However, the risk of cleft lip remained low, at an estimated 1 in 200 babies for women who took topiramate (PMID: 22917484).