We determined the resolution rate of vesicoureteral reflux and the factors that influence it to formulate nomograms to predict the probability of annual resolution for individual cases of reflux. We studied 2,462 children with primary vesicoureteral reflux diagnosed between 1998 and 2006. Cox proportional hazards regression was used to model time to resolution as a function of statistically significant demographic and clinical variables. The resulting model was used to construct nomograms predicting the annual cumulative probability of reflux resolution. Multivariate analysis showed that all cases of unilateral reflux resolved earlier than female bilateral reflux (HR 1.42, p <0.001). Additionally age less than 1 year at presentation (HR 1.31, p <0.001), lower reflux grade (2.96, p <0.001 for grade I; 2.28, p <0.001 for grade II; 1.63, p <0.001 for grade III), reflux diagnosed on postnatal evaluation for prenatal hydronephrosis or sibling screening (1.24, p = 0.002) and single ureter (1.55, p <0.001) were associated with significantly earlier resolution of reflux. Specific predicted cumulative probabilities of reflux resolution at annual intervals from diagnosis (1 to 5 years) were calculated for every possible combination of the significant variables. Our analyses demonstrate that resolution of vesicoureteral reflux is dependent on age at presentation, gender, grade, laterality, mode of clinical presentation and ureteral anatomy. We constructed nomogram tables containing estimates of annual reflux resolution rate as a function of these variables. This information is valuable for clinical counseling and management decisions.

The clinical relevance of prenatal hydronephrosis is not well-defined. We determined the risk of febrile urinary tract infection in the absence of screening for vesicoureteral reflux, and whether postnatal voiding cystourethrography should be performed in patients with a history of prenatal hydronephrosis and postnatally persistent Society for Fetal Urology grade II hydronephrosis. From a longitudinal database of patients with prenatal hydronephrosis maintained since 1998 we identified those with postnatally persistent grade II hydronephrosis. This cohort was divided into patients who were and were not screened with an initial voiding cystourethrogram. The rates of vesicoureteral reflux and development of febrile urinary tract infection were determined. Of 2,076 patients with prenatal hydronephrosis 1,514 had grade II hydronephrosis. Of the patients 76% underwent an initial voiding cystourethrogram and vesicoureteral reflux was found in 28%. There was no relation between laterality of hydronephrosis and incidence of vesicoureteral reflux. There was no difference between nonscreened and screened patients with respect to gender and laterality of hydronephrosis. Urinary tract infection developed in 1.3% of the patients who were screened and did not have vesicoureteral reflux and, therefore, were not receiving antibiotics. Of the screened patients with vesicoureteral reflux who were receiving prophylactic antibiotics urinary tract infection developed in 1.6% at a mean age of 9.4 months. In 363 patients who did not undergo an initial voiding cystourethrogram we estimated (based on the screened population) that 101 would have vesicoureteral reflux and 5 would have a urinary tract infection. However, a febrile urinary tract infection developed in 16 patients (4.4% overall, p <0.0001) at a mean age of 9.3 months. Voiding cystourethrogram performed in these 16 patients revealed vesicoureteral reflux in 12. Of all the patients with a urinary tract infection who were ultimately observed to have vesicoureteral reflux (including those initially screened and those discovered to have reflux after a urinary tract infection) the laterality of hydronephrosis, grade of reflux and laterality of reflux were comparable. In patients with a history of prenatal hydronephrosis who are observed to have postnatally persistent grade II hydronephrosis identification of vesicoureteral reflux and use of prophylactic antibiotics significantly reduce the risk of febrile urinary tract infection. Therefore, we recommend that patients with a history of prenatal hydronephrosis and postnatally persistent hydronephrosis be screened with voiding cystourethrography early in life, and be placed on prophylactic antibiotics until the screening results are known.