Fetal hydantoin syndrome

Fetal hydantoin syndrome, also called fetal dilantin syndrome, is a group of birth defects caused by a developing fetus exposure to the teratogenic effects of phenytoin, an anticonvulsant medication sold as Dilantin and commonly prescribed for epilepsy. About a third of infants exposed to phenytoin in the womb develop symptoms, which can include restricted growth, a small head, facial abnormalities, underdeveloped fingernails, heart defects such as ventricular or atrial septal defects, cleft lip or palate, and developmental delay or intellectual disability, though most infants exposed to the drug do not develop the syndrome. There is no specific diagnostic test; diagnosis rests on recognizing the characteristic pattern of symptoms together with a documented history of prenatal phenytoin exposure, and treatment is individualized, often involving early intervention, therapy services and surgery when needed, particularly for cleft conditions.