“…Children with an antenatal diagnosis of PUJ obstruction reportedly show a significant improvement in renal function after surgery compared with those who are diagnosed and operated much later because of their clinical symptoms [12]. In early published series, King et al [6] encouraged immediate pyeloplasty, regardless of renal function, after obstruction was detected by diuretic renography. In recent years, Koff et al [7,9,15] suggested that unilateral antenatal hydronephrosis caused by PUJ obstruction is a relatively benign condition requiring surgery only in highly selected cases.…”