Non-invasive management of fetal obstructive uropathy.

Fetal outcome was studied in 43 consecutive cases of fetal obstructive uropathy in which no prenatal treatment was undertaken: 12 babies survived. In the 31 who did not survive, oligohydramnios was present in 24 and urethral atresia was the most common cause of obstruction (in 27). At necropsy, bilateral renal dysplasia was found in 23 and pulmonary hypoplasia in 13; 16 had structural or chromosomal anomalies, less than half of which were detected by prenatal ultrasound. In the survivors, 8 had posterior urethral valves, 1 had oligohydramnios, and 2 had associated anomalies. Obstructive uropathy is often associated with other anomalies which may escape prenatal ultrasound detection, and studies to determine the efficacy of intrauterine decompression techniques must allow for this observation.