Case report: the antenatal ultrasound diagnosis of megalourethra.

The antenatal ultrasound findings in a fetus which postnatally had fusiform megalourethra, rectal agenesis, recto-vesical fistula and unilateral renal hypoplasia are described. At 16 weeks gestation a cystic area was seen arising from the perineum. It later became evident that this was the urethra. Initially, an echogenic mass was noted in the pelvis, but by the second trimester, fluid-filled loops of bowel were evident. This combination of developmental abnormalities though rare is well defined. Only one previously recorded case has been suspected antenatally.