To evaluate the severity, laterality, and gender distribution of infant vesicoureteral reflux (VUR) and its potential impact on renal outcome, we compared patients presenting fetally (FDR group) and those presenting with a urinary tract infection (INF group).

A retrospective review of 202 patients with the diagnosis of VUR before 6 months of age was performed. The grade of VUR, gender, laterality, initial renal scarring, breakthrough urinary tract infections, new renal scarring, and surgical intervention were compared between the INF group (n = 146) and FDR group (n = 56).

The male/female ratio in the FDR group was 1.67:1 compared with 0.60:1 in the INF group. The FDR group had more unilateral VUR than the INF group (P <0.001), and no significant difference was found between the two groups in terms of VUR grade distribution (P = 0.13), percentage of initial damage (28% of FDR patients versus 23% of INF patients), or clinical course. In either group, boys and girls exhibited a very similar distribution of grade and renal damage.

Our findings do not support the commonly held belief that fetally diagnosed reflux is an overwhelmingly male, bilateral, and high-grade phenomenon. Few differences were observed between infants diagnosed fetally and those diagnosed subsequent to urinary tract infection. Once diagnosed, from either group, infant reflux has neither great morbidity nor a frequent need for surgery.