OBJECTIVES: Antenatal hydronephrosis is the most common genitourinary pathologic finding during gestational ultrasonography. Congenital midureteral strictures are an unusual cause of prenatal hydronephrosis, with 13 total previously reported and only 1 diagnosed as a result of antenatal ultrasonography. METHODS: We present 4 cases of midureteral strictures as the cause of antenatal hydronephrosis and review the published data on congenital midureteral obstruction. RESULTS: All midureteral strictures in our series and in the published reports were treated surgically after varying periods of observation. Retrograde pyelography was diagnostic in all cases. CONCLUSIONS: This atypical cause of antenatal hydronephrosis may provide additional insight into the controversy regarding preoperative retrograde pyelography before surgical intervention for ureteropelvic junction obstruction. Given the typical misdiagnosis of ureteropelvic junction obstruction in the setting of midureteral stricture disease, we believe that the threshold for retrograde pyelography should be very low.
OBJECTIVES: Antenatal hydronephrosis is the most common genitourinary pathologic finding during gestational ultrasonography. Congenital midureteral strictures are an unusual cause of prenatal hydronephrosis, with 13 total previously reported and only 1 diagnosed as a result of antenatal ultrasonography. METHODS: We present 4 cases of midureteral strictures as the cause of antenatal hydronephrosis and review the published data on congenital midureteral obstruction. RESULTS: All midureteral strictures in our series and in the published reports were treated surgically after varying periods of observation. Retrograde pyelography was diagnostic in all cases. CONCLUSIONS: This atypical cause of antenatal hydronephrosis may provide additional insight into the controversy regarding preoperative retrograde pyelography before surgical intervention for ureteropelvic junction obstruction. Given the typical misdiagnosis of ureteropelvic junction obstruction in the setting of midureteral stricture disease, we believe that the threshold for retrograde pyelography should be very low.