Fetal urogenital sinus with consecutive hydrometrocolpos because of labial fusion: prenatal diagnostic difficulties and postpartal therapeutic management.

OBJECTIVE: To elucidate the differential diagnoses of tumorous dilations in the fetal pelvic region detected by prenatal ultrasound and the postnatal management demonstrated on a fetus with 29 weeks of gestation with a retrovesical located bottle-like cystic structure measuring 54 x 31 x 27 mm within the pelvis. Postnatal findings were a labial fusion and a consecutive hydrometrocolpos due to a urethrovaginal fistula.

METHOD: Case report of a fetus affected by an intricate cloacal anomaly.

RESULTS: The long-term prognosis for this nonsyndromic form of hydrometrocolpos without any other structural defects or organic failures after operative sanitation is excellent. Final reconstruction is planned at about 12 months of age.

CONCLUSION: Prenatal diagnosis of tumorous dilations in the fetal pelvic region often involves difficulties because of numerous differential diagnoses and possible presentation in late pregnancy. Magnetic resonance imaging could be a useful complementary tool for assessing these anomalies when ultrasonography is inconclusive. In some cases, the final diagnosis cannot be confirmed until after delivery.