Clinical outcome and follow-up of prenatal hydronephrosis.

Between 1987 and 1991, 160 hydronephrotic kidneys were diagnosed prenatally and confirmed postnatally in 100 infants. The aim of the study was to describe the natural history and management of primary hydronephrosis detected prenatally. We devised a new classification of obstructive uropathy outcome using ultrasonography and the diethylenetriamine penta-acetic acid scan. Accordingly, we classified the patients as having mild, moderate or severe hydronephrosis. Nine patients had pyeloplasties and 5 had ureteric reimplantations. We conclude that in most cases there is no need for immediate surgery, and that the initial approach to the management of congenital hydronephrosis should be conservative. We suggest that anti-bacterial prophylaxis be conventionally given to infants with vesicoureteral reflux and for the first 6 months of life to infants demonstrating moderate to severe newborn primary hydronephrosis.