A multicenter outcomes analysis of patients with neonatal reflux presenting with prenatal hydronephrosis

Approximately 10 to 30% of prenatal cases of hydronephrosis result in the postnatal diagnosis of vesicoureteral reflux. Using a new generic prenatal-postnatal data sheet developed by the Society for Fetal Urology the characteristics, natural history and outcome of prenatal hydronephrosis confirmed postnatally to be vesicoureteral reflux were documented at 3 centers.

We performed a retrospective multicenter review of Society for Fetal Urology data sheets completed for each patient in whom prenatal hydronephrosis was proved to be postnatal vesicoureteral reflux from 1993 to 1998.

In 56 male and 15 female patients with prenatal hydronephrosis a total of 116 refluxing renal units were confirmed postnatally. Of the 116 renal units 112 were hydronephrotic prenatally. During gestation increased hydronephrosis was noted with voiding in 4 cases. Of the 112 hydronephrotic renal units only 26 ureters in 15 patients were seen prenatally. The obstetrician considered the diagnosis of vesicoureteral reflux in only 24% of the cases. Postnatally 116 refluxing renal units were identified. Initial postnatal ultrasound was normal in 25% of the cases. Bilateral reflux was present in 36 male and 9 female patients. In 10 of the 19 uncircumcised patients (53%) urinary tract infection developed despite antibiotic prophylaxis. In 15 of the 74 renal units with grades III to V reflux the condition resolved at an average patient age of 0.9 and 2.1 years in boys and girls, respectively. A total of 27 refluxing renal units were reimplanted.

The majority of prenatal reflux occurs in boys, and it is high grade and bilateral. The data sheets designed by the Society for Fetal Urology are useful data collection instruments. The presentation and natural history of vesicoureteral reflux are different in male and female individuals. In a significant number of renal units high grade reflux resolves spontaneously. Early circumcision may decrease the incidence of breakthrough urinary tract infection in this subpopulation. In addition, the effective management of prenatally detected reflux depends on multispecialty communication.