The Fetal Hydantoin Syndrome refers to a variety of congenital malformations and developmental problems that occur in an infant born to an epileptic female who took diphenylhydantoin (Dilantin) during the pregnancy.



(1) exposure to hydantoin during pregnancy

(2) exclusion of other conditions

(3) presence of phenotypic traits


Supportive evidence: siblings not exposed to dilantin are phenotypically normal


More common phenotypic features at birth:

(1) low birth weight

(2) hypertelorism

(3) shallow and broad nasal bridge

(4) microcephaly

(5) wide mouth

(6) short nose


Less common findings:

(1) colobomata

(2) strabismus

(3) high palate

(4) cleft lip and/or palate

(5) broad alveolar ridges

(6) short neck

(7) cystic hygroma

(8) inguinal hernia

(9) nail hypoplasia

(10) hirsutism

(11) cranial asymmetry

(12) rib or vertebral anomalies

(13) scoliosis

(14) hypoplastic distal digits

(15) hip dislocation

(16) club feet

(17) pyloric stenosis or duodenal atresia

(18) imperforate anus

(19) diaphragmatic hernia

(20) cardiac malformation

(21) hyposplenism

(22) renal hypoplasia or urinary tract anomalies

(23) urogenital defects in males (hypospadias, cryptorchidism, micropenis, bifid scrotum)

(24) holoprosencephaly

(25) wide anterior fontanelle

(26) seizures

(27) vision problems


Developmental problems:

(1) growth deficiency, with short stature

(2) developmental delay

(3) mild cognitive and/or learning disability


To read more or access our algorithms and calculators, please log in or register.