Teratogenicity of anticonvulsant drugs. IV: The association of clefting and epilepsy.

Cleft lip with or without cleft palate (CL/P) is the most common congenital malformation reported among infants of epileptic mothers. This study sought to examine the relative roles of anticonvulsant teratogenicity and other factors responsible for this association. Among 175 families with a proband with isolated CL/P, there were 13 parents with epilepsy and a high frequency of other family members with CL/P and epilepsy. Evaluation of the 13 cases suggested that teratogenicity of anticonvulsant drugs was not the primary factor responsible for the observed association of maternal epilepsy and clefting. Among 140 families with a proband with clefting other than CL/P, there were no instances of parental epilepsy observed.