Fetal Hydantoin syndrome
Incidence
1 in 2000 live births with subtle fetal effects being 2-3 times more common. Sporadic disorder due to maternal hydantoin intake; epoxide hydrolase levels may influence effects on fetus.
Clinical Characteristics
Fetal hydantoin syndrome refers to a pattern of growth deficiency, developmental delay, and malformations in children who were exposed to hydantoin (phenytoin, Dilantin) during pregnancy. Fetuses exposed to phenytoin have a 5-10% percent risk of developing the full-blown hydantoin syndrome. Clinical pattern including a distinctive face with hypertelorism, shallow and broad nasal bridge, short nose, and wide mouth; eye anomalies including colobomata and strabismus; cleft palate or broad alveolar ridges, small terminal digits and nails; orthopedic anomalies including club feet, dislocated hip, or scoliosis; cardiac and urinary outflow defects. Major complications include low birth weight or delayed growth after birth, small head circumference with developmental delays, feeding problems due to gastrointestinal anomalies, and a variety of anomalies affecting the heart, skeleton, or urinary tract. The face may appear different, with widely spaced eyes, shallow and broad nasal bridge, short nose, and wide mouth. Eye anomalies include ptosis (hooding of the upper lids), colobomata (clefts in the iris or retina), and strabismus (wandering eyes). Cleft or high palate with broad ridges near the gums can be noted inside the mouth, and the neck is often short with webbing or redundant skin. Small ends of the digits and small nails are the most distinctive skeletal anomaly, but congenital hip dislocation, club feet, rib anomalies, spinal anomalies, and scoliosis (curved spine) can occur. Cardiac septal defects, urinary outflow tract obstruction, small penis or cryptorchidism (undescended testicles) in males, and occasional brain anomalies have been reported.
Precipitants
No attacks. The cause is exposure to Dilantin during pregnancy.
Provocation Tests
no
Diagnostic Procedures
The diagnosis of fetal hydantoin syndrome depends on recognition of the distinctive pattern of anomalies in infants with documented exposure to the drug.