Hypospadias mimicking female genitalia on early second trimester sonographic examination.

Female fetal sex was assigned based on downward direction of the genital tubercle at 14 weeks' gestation. Subsequently, amniocentesis performed due to the finding of an echogenic focus in the left ventricle revealed a male karyotype. Sonographic examination at 22 weeks' gestation revealed a markedly curved penile shaft. Power Doppler at that time demonstrated a urine jet emanating from the penile base, verifying the diagnosis of penoscrotal hypospadias. We therefore suggest that female fetal sex assignment should be based on the demonstration of the 2 or 4 parallel lines representing the labial folds and not only upon the demonstration of the downward direction of the genital tubercle.