32-week pregnancy presented with anomaly seen in trans-abdominal sonographic images.

Bilateral ureteropelvic junction obstruction

Ovarian cyst with bilateral hydronephrosis

Mesenteric cyst with bilateral hydronephrosis

Diagnosis: Urogenital sinus (persistent cloacal malformation)

There is bilateral severe hydronephrosis in the fetus. A cystic structure is seen in fetal abdomen with echogenic matter within it. This is the fetal bladder containing fecal matter/meconium due to the cloacal malformation. Postnatal examination confirmed the findings with a single, shared opening between the urinary bladder, rectum, and uterus/vagina.

Persistent cloaca, or urogenital sinus, is the presence of a shared chamber or outlet for the urinary bladder, vagina and uterus, and the rectum. This results in a single opening as an outlet for genitourinary and gastrointestinal systems. This causes a number of variable appearances on sonography, including hydronephrosis which may be unilateral or bilateral and a distended bladder containing fecal matter from the rectum. In other cases, there may be distended bowel loops or calcific foci within the fetal bladder, as well as ascites or hydrocolpos. The presence of a persistently distended urinary bladder in a female fetus with echogenic matter within it is one of the signs suggesting possible urogenital sinus (persistent cloacal malformation). This is an extremely rare congenital anomaly with an incidence of 1:50,000 female fetuses.

1. Rumack CM. Diagnostic Ultrasound. Ch. 39, 1377. 2011.

2. Livingston JC, Elicevik M, Breech L, Crombleholme TM, Pena A, Levitt MA. Persistent cloaca: a 10-year review of prenatal diagnosis. 

Image IQ: 32-week Female Fetus with Anomaly