Antenatal hydronephrosis.

The diagnosis, workup, and management of prenatal hydronephrosis have undergone a swing from preemptive surgical treatment to a more conservative approach as the natural history of the differential diagnoses becomes more appreciated. We examine different radiologic tests for determining the diagnoses associated with antenatal hydronephrosis. A review of the more common differential diagnoses of prenatal hydronephrosis and current treatment options for ureteropelvic junction obstruction, vesicoureteral reflux, ureteroceles, ectopic ureters, and megaureters is undertaken.