Natural history of neonatal reflux associated with prenatal hydronephrosis: Long-term results of a prospective study

Purpose: We have previously reported on patients with neonatal vesicoureteral reflux followed conservatively. The current study is a long-term followup of our prospective expectant management protocol for the overall cohort. Materials and Methods: Between 1993 and 1998, 31 of 260 patients with prenatal hydronephrosis had vesicoureteral reflux and were followed prospectively. Outcome analysis was done on 25 patients, excluding 6 who underwent surgery, with the end point of complete resolution or improvement of reflux using our previously reported Kaplan-Meier survival curve, urinary tract infection, dysfunctional voiding, and changes in renal function or growth, somatic growth and hypertension. Results: Of the 25 cases reflux was grades I to V in 7%, 20%, 34%, 16% and 23%, respectively. Reflux resolved in 13 patients (52%) and improved in 6 (24%). Grades I to V disease resolved in 100%, 77%, 53%, 28% and 40% of refluxing units, respectively. The improvement rate for grades III to V reflux was 13%, 14% and 30%, respectively. Breakthrough urinary tract infection occurred in 4 patients with grades IV and V reflux, and dysfunctional voiding developed in 5. Followup renal scans showed 19% and 17% decreased differential function in 2 units without new scars. There was no difference in renal length in patients with resolved versus persistent reflux or low versus high grade reflux. All patients had normal somatic growth at the 4-year followup and none had hypertension. Conclusions: Expectant management was effective in the majority of cases and associated with a low urinary tract infection rate. Neonatal vesicoureteral reflux resolved or improved in 76% of our patients by age 4 years without somatic growth retardation or hypertension. High grade reflux resolved or improved in 59% of the units and showed normal renal growth with expectant management.