Congenital ureteropelvic junction obstruction is considered one of the common causes of prenatally diagnosed hydronephrosis , which if left untreated , it can lead to progressive renal impairment [1].UPJ obstruction is Congenital ureteropelvic junction obstruction is considered one of the common causes of prenatally diagnosed hydronephrosis , which if left untreated , it can lead to progressive renal impairment [1].UPJ