Results of systematic voiding cystourethrography in infants with antenatally diagnosed renal pelvis dilation

Abstract

Objectives: To assess the yield of neonatal renal ultrasonography as a predictor of abnormalities on voiding cystourethrography (VCUG).

Study design: We prospectively followed 264 infants with antenatal renal pelvis dilation. Two successive neonatal renal ultrasound examinations were performed at day 5 and 1 month after birth. VCUG was performed in all infants.

Results: Neonatal ultrasound findings were abnormal in 190 infants (72% of total). Among them, 63 (33%) had an abnormal VCUG. The most common abnormalities were primary vesico-ureteral reflux (VUR) in 30 infants, VUR into the lower pole of a duplex kidney in 14, refluxing megaureter in 9, posterior urethral valves in 5, and ureterocele in 5. When both neonatal ultrasound findings were normal (74 infants), the VCUG showed abnormalities in only 5 (6.7%) patients (4 low-grade primary VUR and 1 posterior urethral valve). The sensitivity, specificity, positive predictive value, and negative predictive value of 2 successive ultrasound scans in the neonatal period to predict an abnormality on VCUG were 93%, 35%, 33%, and 93%, respectively.

Conclusions: A normal-appearing urinary tract on 2 successive neonatal ultrasound scans rarely coexists with abnormal findings at VCUG. Therefore, in such patients, VCUG does not seem justified.