Predictors of spontaneous resolution of prenatally detected primary non-refluxing megaureter: A retrospective cohort study.

Abstract

Introduction. Obstetric ultrasonography increased the detection of primary megaureters (PM); the most common type is non-refluxing, with a tendency to spontaneous resolution. Objectives. To determine predictors and time to spontaneous resolution and incidence of urinary tract infection (UTI) with and without antibiotic prophylaxis (AP). Population and methods. Retrospective cohort. The PM was defined as an anteroposterior diameter (APD) of the retrovesical ureter ≥7 mm, with or without pelvic dilatation (≥10 mm), at the first postnatal ultrasound. Spontaneous resolution was the absence of dilatation or a ureter APD <7 mm and pelvis <10 mm. Results. Seventy patients presented with PM, 15 bilateral. Of the 85 PM, 53 (62%) resolved spontaneously. In these patients, the ureter and pelvic APD at the first postnatal ultrasound were lower than those requiring surgery (p = 0.0001). A ureteral APD ≥10 mm and pelvic APD ≥15 mm increased the risk of surgery 2.63 and 4.57 times, respectively. The median time to spontaneous resolution was 6 and 33 months for ureters with APD < or ≥10 mm (p = 0.009) respectively. The incidence of UTI in the first year was 0.21. There were 7/22 children with AP and 7/44 without AP. Conclusion. Two-thirds of the MPs resolved spontaneously in a median of 6 months, with ureter and pelvic APD at birth being predictors. The incidence of UTI was 0.21; it was more frequent in more dilated ureters.