Prenatal Diagnosis and Fetal Sonographic Features of Swyer Syndrome

Abstract Swyer syndrome, also known as complete gonadal dysgenesis, is characterized by an individual who has an XY karyotype but is phenotypically female. It is typically diagnosed in adolescence after investigations for primary amenorrhea. The estimated prevalence is 1 in 20,000 to 80,000 births. Mutations in the DNA-binding region of the SRY gene account for approximately 15 to 20% of cases, with the remaining cases caused by other gene mutations. There are no reports of the established diagnosis of Swyer syndrome prenatally, or of the sonographic features that may be associated with it. This report outlines the details of a 33-year-old primigravida in whom a fetal cystic hygroma was noted on ultrasound at 12 weeks gestation. Chorionic villous sampling revealed a diagnosis of fetal Swyer syndrome. The fetus progressed to develop severe fetal hydrops and a parental decision for termination of pregnancy was made at 15 weeks of gestation.