Fetal Dilantin syndrome

Dilantin is the brand name of the drug phenytoin sodium in the United States, commonly used in the treatment of epilepsy. About one third of children whose mothers are taking this drug during pregnancy develop minor face and limb birth defects. A smaller population will have growth problems and developmental delay, or mental retardation. Heart defects and cleft lip may also be featured. The entire group of defects caused by the drug's teratogenicity is called Fetal Dilantin Syndrome. It may also be called Fetal Hydantoin Syndrome, Dilantin Embryopathy, or Phenytoin Embryopathy.

ymptoms

*Abnormalities of the skull and facial features
*Growth deficiencies
*Underdeveloped nails of fingers and toes
*Mild developmental delays
*Occasionally, cleft lip and/or palate, microcephaly, and brain malformations with more significant developmental delays may present.

Fetal Hydantoin Syndrome (FHS)Meadow SyndromeCongenital Hydantoin SyndromeDilantin SyndromeFetal Dilantin SyndromeFetal Phenytoin SyndromeHydantoin Syndrome …Multiple abnormalities in infants whose mothers were treated for epilepsy with hydantoin anticonvulsants during pregnancy. The abnormalities include disorders of growth and mental development, dysmorphic facies, and osteoarticular, cardiovascular, and other anomalies. Neoplasms complicate some cases.Head and neck: Microcephaly, brachycephaly, midfacial hypoplasia, wide fontanels, metopic ridging, and mild micrognathia.Ears: Low-set deformed ears.Eyes: Blepharoptosis, mild hypertelorism, and strabismus.Nose: Short nose with a broad depressed bridge and epicanthal folds.Mouth and oral structures: Cupid's bow of the upper lip and occasional cleft lip/and palate.Neck: Short neck with mild webbing.Thorax: Widely spaced nipples.Abdomen: Umbilical or inguinal hernia.Hand and foot: Finger-like thumbs, aplasia or hypoplasia of the distal phalanges, supernumerary phalangeal epiphyses, and clubfoot. Dermatoglyphic abnormalities consist of abnormal palmar creases.Skin appendages: Coarse hair, hirsutism, low hairline, and nail hypoplasia.Cardiovascular system: Variable coarctation of the aorta, endocardial cushion defect, double outlet right ventricle, ventricular septal defect, atrial septal defect, and bicuspid pulmonic valve.Gastrointestinal system: Intestinal malrotation.Hematopoietic system: Hemorrhagic complications.Growth and development: Growth and mental retardation.Etiology and pathogenesis: Teratogenic and potential carcinogenic effects of phenytoin and related hydantoin anticonvulsants.Additional features: Neuroblastoma, mesenchymoma, and Wilms tumor have been reported in some infants.

Dilantin is a drug commonly used in the treatment of epilepsy. About one third of children whose mothers are taking this drug during pregnancy have minor face and limb birth defects. A smaller proportion may have growth problems and developmental delay or mental retardation. Cleft lip and heart defects are occasional features.

Fetal Hydantoin Syndrome is a rare disorder that is caused by exposure of a fetus to the anticonvulsant drug phenytoin (Dilantin). The symptoms of this disorder may include abnormalities of the skull and facial features, growth deficiencies, underdeveloped nails of the fingers and toes, and/or mild developmental delays. Other findings occasionally associated with this syndrome include cleft lip and palate, having an unusually small head (microcephaly) and brain malformations with more significant developmental delays.

Safe usage during pregnancy has not been established.Reports in recent years indicate a higher incidence of congenital abnormalities in children whose mothers used anticonvulsant medication during pregnancy. Reported abnormalities include cleft lip/palate, heart malformations, and the fetal hydantoin syndrome (consisting of craniofacial abnormalities, nail and digital hypoplasia, prenatal growth deficiency, microcephaly and mental deficiency associated with intrauterine development during therapy). There is good evidence of a genetic predisposition to congenital abnormalities induced by phenytoin.There have been isolated reports of malignancies, including neuroblastoma, in children whose mothers received phenytoin during pregnancy.Usage should not be discontinued if the medicine is administered to prevent major seizures because of the possibility of precipitating status epilepticus with attendant hypoxia and threat to life.Because of altered absorption, increased protein binding, and/or increased metabolic clearance of hydantoin anticonvulsants during pregnancy, pregnant women receiving hydantoins may experience an increased incidence of seizures. Serum hydantoin concentrations must be monitored and doses increased accordingly. A gradual resumption of the patient's usual dosage may be necessary after delivery.Exposure to hydantoin anticonvulsants prior to delivery may lead to an increased risk of life-threatening haemorrhage in the neonate, usually within 24 hours of birth. Hydantoins may also produce a deficiency of vitamin K in the mother, causing increased maternal bleeding during delivery. The risk of maternal and infant bleeding may be reduced by administering water-soluble vitamin K to the mother during delivery and to the neonate, intramuscularly or subcutaneously immediately after birth. Some patients may experience a rapid reduction in maternal hepatic phenytoin metabolism at the time of delivery, requiring the dosage to be reduced within 12 hours postpartum.