Purpose : The detection of hydronephrosis(HN) with antenatal ultrasonography was first reported in the 1970s. Prenatal HN is diagnosed with an incidence of 1:100 to 1:500 on antenatal screening. Recently, the purpose of antenatal screening has changed from simple detection to selection for specific diagnosis-based management. this study is to evaluate the usefulness of antenatal sonography for HN and to investigate the differential causes of HN and their clinical outcomes.
Patients and methods : 11,783 live neonates with prenatal ultrasonographic examination at Ajou University School of Medicine, from Sep. 1994 to Aug. 2001 were analyzed.
Results and conclusion : Hydronephrosis (>10 mm) was detected in 119 (1.0%) cases antenatally and among these, 91 were proved to have HN postnatally Males were three times more affected than females. Additional imaging studies revealed that ureteropelvic junction obstruction was the most common postnatal diagnosis (47%), followed by multicystic dysplastic kidney, vesicoureteral junction obstruction and vesicoureteral reflux. During 20 months’’ follow-up(3 to 72 months), 58(48%) renal units showed spontaneous resolution and surgical interventions were necessary in 10 (7.4%) of postnatally confirmed hydronephrotic renal units.