Transvaginal ultrasonography and transabdominal embryoscopy in the first-trimester diagnosis of Smith-Lemli-Opitz syndrome, type II.

Abstract

Our goal was to demonstrate the efficacy of transabdominal embryoscopy in the first trimester of pregnancy. A patient at risk for Smith-Lemli-Opitz syndrome, type II, was referred for prenatal diagnosis at 11 weeks 5 days of gestation. A transvaginal ultrasonographic examination revealed the presence of a nuchal membrane and bilateral polydactyly. A transabdominal embryoscopy confirmed the diagnosis of polydactyly. The patient had an unremarkable postprocedure course before termination of pregnancy 5 days later. In a second pregnancy embryoscopy revealed a normal fetal hand despite a suggestion on transvaginal ultrasonography that there was polydactyly. On the basis of this information the patient elected to continue the pregnancy, and a normal baby was delivered at 35 weeks. This case validates the efficacy of noninvasive and invasive techniques, used adjunctively, in the first-trimester diagnosis of a lethal fetal condition composed of subtle phenotypic manifestations.