Fetal hydantoin syndrome in triplets. A unique experiment of nature.

Birth defects associated with phenytoin and phenobarbital taken during pregnancy include craniofacial and limb deformities. These anomalies were found in various degrees of severity in triplets born to a mother taking phenobarbital and phenytoin for an epileptic disorder, giving us a unique opportunity to recognize different manifestations of the hydantoin syndrome in infants that presumably were exposed to the same level of the drugs. These infants were trizygotic and their clinical manifestations varied widely, suggesting the possibility that genetic background may play a significant role in the susceptibility of the fetus to phenytoin and phenobarbital during pregnancy.