American Academy of Pediatrics Committee on Drugs: anticonvulsants and pregnancy.

There is an increased risk of congenital heart disease and cleft palate among the offspring of women with epilepsy, most of whom are on anticonvulsants. Part of this increase may be caused by phenytoin. The risk of all abnormalities in these infants appears to be about 4% to 5%, which is approximately double the rate of malformations in the general population. There appears to be an ill-defined "syndrome" associated with fetal exposure to hydantoin, although it has not been proven to be caused by the drug. The risk of this "syndrome" is of unknown magnitude, but it is probably less than 10%. The significance to a given child of the abnormalities in this "syndrome" is not predictable at this time.