Prenatal Diagnosis of Sex Differentiation Disorders: The Role of Fetal Ultrasound

We describe our experience with prenatal diagnosis of sex differentiation disorders, with focus on the role of ultrasound scans for coherent assessment of prenatal diagnosis. Over a 5-yr period all cases suspected of sexual ambiguity based on abnormal ultrasonographic scans (US) or US/genotype US discrepancy were evaluated prenatally by three modalities: 1) repeated fetal US; 2) genetic studies, primarily karyotype and fluorescence in situ hybridization analysis of sex-determining region on the Y gene (SRY); and 3) hormonal assays of amniotic fluid. Of approximately 10,000 gestations, 16 fetuses underwent prenatal evaluation. Twelve were referred because of an abnormal US and 4 because of genotype-phenotype discrepancy. Five fetuses were diagnosed with female pseudohermaphroditism (21-hydroxylase deficiency in 3 and urorectal septum malformation sequence in 2). Four fetuses were diagnosed with male pseudohermaphroditism (1 with steroid sulfatase deficiency, 1 with presumed camptomelic dysplasia, and 2 und...