Background: Although the majority of cases with antenatally detected hydronephrosis (ANH) resolve during postnatal period; patients should be monitored for the risk of developing ureteropelvic junction obstruction (UPJO) which requires surgical intervention. We aimed to define independent risk factors for operation in whom diagnosis of UPJO was precisely proven with histopathological evidence.
Methods: Medical files of 155 children (186 renal units) with anteroposterior pelvic diameter (APPD) ≥ 7 mm or ≥ 1SFU (Society of Fetal Urology) grade of pelvicalyceal dilatation were retrospectively investigated.