Teratogenic Effects of Antiepileptic Medications

During the last few years epilepsy and pregnancy registries and other large scale observational studies have provided new information on the teratogenic effects of the most frequently used antiepileptic drugs (AEDs). The prevalence of major congenital malformations associated with exposure to carbamazepine or lamotrigine appears to be only marginally increased from the expected, while malformation rates with valproate have been reported to be 2 to 4 times higher. Recent studies also suggest that compared with carbamazepine, lamotrigine and phenytoin, exposure to valproate in utero may be associated with poorer postnatal cognitive development. However, adverse outcomes with valproate appear to be dose-related, and doses below 800-1,000 mg/day might not be associated with worse outcome than with other AEDs. Information on the teratogenic potential of other newer generation AEDs than lamotrigine is still insufficient.