FDA Drug Safety Communication

The U.S. Food and Drug Administration (FDA) is informing the public that children born to mothers who take the anti-seizure medication valproate sodium or related products (valproic acid and divalproex sodium) during pregnancy have an increased risk of lower cognitive test scores than children exposed to other anti-seizure medications during pregnancy. This conclusion is based on the results of epidemiologic studies that show that children born to mothers who took valproate sodium or related products throughout their pregnancy tend to score lower on cognitive tests (IQ and other tests) than children born to mothers who took other anti-seizure medications during pregnancy.

In the primary epidemiologic study upon which FDA's conclusion is based, cognitive tests were performed at age three. In supportive studies, cognitive tests were performed at ages five to 16. Cognitive tests are commonly used to assess development in a variety of areas, including intelligence, abstract reasoning, and problem solving.

The long-term effects on cognitive development from exposure to valproate sodium or related products during pregnancy are unknown. It is also not known whether these effects occur when fetal exposure is limited to less than the full duration of pregnancy, such as the first trimester.

FDA has evaluated all available evidence to date, and will be adding information about the risk of lower cognitive test scores to the valproate product labels in the Warnings and Precautions section, the Use in Specific Populations: Pregnancy section, and to the Medication Guides that are being developed for the valproate drug products.

FDA previously warned pregnant women and women of childbearing age about valproate use during pregnancy due to the known risk of birth defects (teratogenic effects) of these products. A teratogen is anything known to cause birth defects during development of an embryo or fetus. Valproate products are assigned to Pregnancy Category D. FDA released an Information for Healthcare Professionals communication in December 2009 on the risk of neural tube birth defects following exposure to valproate products during pregnancy.

The benefits and the risks of valproate sodium and related products should be carefully weighed when prescribing these drugs to women of childbearing age, particularly for conditions not usually associated with permanent injury or death. If the use of valproate is not essential, alternative medications that have a lower risk to the fetus of birth defects and adverse cognitive effects should be considered in pregnant women and women of childbearing age. If the decision is made to use valproate in women of childbearing age, effective birth control should be used.

View the full FDA Drug Safety Communication on FDA.gov