A case of prenatal diagnosis of fetal hydantoin syndrome by ultrasound

Abstract

Fetal hydantoin syndrome (FHS) is a set of disruptions occasionally present in fetuses exposed in utero to phenytoin or other anticonvulsants. Administration of phenytoin in early pregnancy may impair proper psychomotor performance expected for children's development. Several combined phenotypic markers delineate the syndrome, but the presence of single clinical signs is more common. There is controversy about the etiology of FHS. Associated disruptions may be related to a deficiency in a detoxifying enzyme (epoxide hydrolase), vascular problems, and/or factors not yet known. Genetic causes are believed to influence susceptibility to the drug. This text reports an unusual pattern of malformations detected in an ultrasound scan (gastroschisis, sacral meningomyelocele, and absence of the right lower limb) and in the anatomopathological study (left-side gastroschisis, sacral meningomyelocele, scoliosis, left clubfoot, absence of the right lower limb, and pectus carinatum) of a fetus whose mother took phenytoin. These defects may have been provoked by exposure to the drug during embryogenesis. In view of similar malformations observed in cases of prenatal exposure to cocaine, a recognized vasoconstrictor, it is suggested that vascular disruptions of hemodynamic origin constituted the event leading to some of the anomalies caused in the developing embryo. A complication of the chorionic villus sampling procedure, used for cytogenetic analysis, is another possibility.<br>A síndrome da hidantoína fetal consiste em um conjunto de disrupturas por vezes observadas em fetos expostos à fenitoína ou outros anticonvulsivos no período pré-natal. A administração de fenitoína em fase precoce da gravidez pode prejudicar o desempenho psicomotor esperado no desenvolvimento infantil. Diversos indicadores fenotípicos, em conjunto, caracterizam a síndrome, mas a presença de sinais clínicos isolados é mais comum. Há controvérsia quanto à sua etiologia. As disrupturas associadas podem estar relacionadas à deficiência de uma enzima desintoxicante (epóxide-hidrolase), a problemas vasculares e/ou a fatores ainda desconhecidos. Acredita-se haver causas genéticas conferindo susceptibilidade à substância. Este texto relata um padrão distinto de malformações detectadas no período pré-natal ao ultra-som (gastrosquise, meningomielocele sacral, escoliose, ausência do membro inferior direito), bem como posteriormente ao exame anatomopatológico (gastrosquise à esquerda, meningomielocele sacral, escoliose, pé esquerdo torto, ausência do membro inferior direito e pectus carinatum) de feto cuja mãe fez uso de fenitoína. Os defeitos podem ter se originado da exposição à droga durante a embriogênese. Em vista de malformações semelhantes observadas em casos de exposição pré-natal à cocaína, um conhecido vasoconstritor, sugere-se que rupturas vasculares de origem hemodinâmica constituíram o evento por trás de algumas das anomalias causadas no embrião em desenvolvimento. Uma complicação do procedimento de coleta de amostra de vilo corial utilizado para anál...

An update on maternal medication‐related embryopathies

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