Study of 284 births in Rochester, Minn, to 138 women who had epilepsy suggests (as have other studies) that there is an increased incidence of malformations among the offspring of women taking anticonvulsants. Among the 141 children born to mothers taking one or more of the anticonvulsants, ten had serious malformations, including five with congenital heart lesions, two with cleft palate, and one with both heart and palate anomalies. Among 56 offspring to mothers with epilepsy who did not take anticonvulsants in the first trimester but were comparable with the 141 in respect to age, parity, and type of seizure, there was one malformation (agenesis of the testis). There were no malformations among 26 offspring of mothers whose epilepsy had been in remission or among 61 offspring of mothers whose pregnancies predated the epilepsy.