Fetal hydantoin syndrome, also called fetal dilantin syndrome, is a group of defects caused to the developing fetus by exposure to teratogenic effects of

phenytoin Phenytoin (PHT), sold under the brand name Dilantin among others, is an anti-seizure medication. It is useful for the prevention of tonic-clonic seizures (also known as grand mal seizures) and focal seizures, but not absence seizures. The in ...

. Dilantin is the

brand name A brand is a name, term, design, symbol or any other feature that distinguishes one seller's good or service from those of other sellers. Brands are used in business, marketing, and advertising for recognition and, importantly, to create an ...

of the drug phenytoin sodium in the United States, commonly used in the treatment of

epilepsy Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrica ...

. It may also be called congenital hydantoin syndrome, fetal hydantoin syndrome, dilantin embryopathy, or phenytoin embryopathy. Association with EPHX1 has been suggested.

Signs and symptoms

About one third of children whose mothers are taking this drug during pregnancy typically have

intrauterine growth restriction Intrauterine growth restriction (IUGR), or fetal growth restriction, refers to poor growth of a fetus while in the womb during pregnancy. IUGR is defined by clinical features of malnutrition and evidence of reduced growth regardless of an infant's ...

with a small head and develop minor dysmorphic craniofacial features (microcephaly and intellectual disability) and limb defects including hypoplastic nails and distal phalanges (

birth defects A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...

). Heart defects including

ventricular septal defect A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one ...

atrial septal defect Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this d ...

patent ductus arteriosus ''Patent ductus arteriosus'' (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs by flowing from the aorta, which has ...

and coarctation of the aorta may occur in these children. A smaller population will have growth problems and

developmental delay Global developmental delay is an umbrella term used when children are significantly delayed in their cognitive and physical development. It can be diagnosed when a child is delayed in one or more milestones, categorised into motor skills, speech ...

, or

intellectual disability Intellectual disability (ID), also known as general learning disability in the United Kingdom and formerly mental retardation, Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010). is a generalized neurodevelopmental disorder characterized by signif ...

Heart defect A congenital heart defect (CHD), also known as a congenital heart anomaly and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital heart defect is classed as a cardiovascular ...

s and

cleft lip A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nose. The te ...

may also be featured.

Diagnosis

There is no diagnostic testing that can identify fetal hydantoin syndrome. A diagnosis is made clinically based upon identification of characteristic symptoms in an affected infant in conjunction with a history of phenytoin exposure during gestation. It is important to note that the majority of infants born to women who take phenytoin during pregnancy will not develop fetal hydantoin syndrome.

Treatment

The treatment of fetal hydantoin syndrome is directed toward the specific symptoms that are apparent in each individual. Treatment may require the coordinated efforts of a team of specialists. Pediatricians, oral surgeons, plastic surgeons, neurologists, psychologists, and other healthcare professionals may need to systematically and comprehensively plan an affected child's treatment. Infants with fetal hydantoin syndrome can benefit from early developmental intervention to ensure that affected children reach their potential. Affected children may benefit from occupational, physical and speech therapy. Various methods of rehabilitative and behavioral therapy may be beneficial. Additional medical, social and/or vocational services may be necessary. Psychosocial support for the entire family is essential as well. When cleft lip and/or palate are present, the coordinated efforts of a team of specialists may be used to plan an affected child's treatment and rehabilitation. Cleft lip may be surgically corrected. Generally surgeons repair the lip when the child is still an infant. A second surgery is sometimes necessary for cosmetic purposes when the child is older. Cleft palate may be repaired by surgery or covered by an artificial device (prosthesis) that closes or blocks the opening. Surgical repair can be carried out in stages or in a single operation, according to the nature and severity of the defect. The first palate surgery is usually scheduled during the toddler period.

References

External links

{{Congenital malformation due to exogenous toxicity Congenital malformation due to exogenous toxicity Syndromes