Does vesicoureteric reflux diagnosed following prenatal urinary tract dilatation need active management? A narrative review.

Vesicoureteric reflux (VUR) diagnosed following investigation of prenatally-detected urinary tract dilatation (UTD), often remains asymptomatic and yet raises much parental and medical anxiety and management conundrums. Previous studies suggest that "prenatal" VUR appears to have a different natural history to that of VUR diagnosed following investigation of recurrent febrile urinary tract infections (UTIs). The concept is not new: reports from Great Ormond Street (1997) and the Society for Fetal Urology registry (1999) highlighted the characteristics of VUR patients diagnosed following investigation of prenatal hydronephrosis, who were noted to be predominantly male with high-grade VUR and established renal uptake defects on DMSA. To date, studies on VUR management and outcome have included both prenatally-diagnosed and symptomatic patients, confounding the results. Studies focussing specifically on the asymptomatic cohort are few, and generally only include patients on prophylaxis. Hence the true natural history of the condition is not known. A systematic review of 18 articles including 829 asymptomatic infants, of whom 473 (69.4 %) were males and 48.7 % had high grade (IV-V) VUR, revealed that 15.4 % of infants developed at least one breakthrough UTI despite initiation of CAP from birth. The limited data available showed no conclusive benefit of CAP, primarily due to lack of a strong comparator cohort. The recent PREDICT trial is the only randomised controlled trial to date, specifically on asymptomatic patients, assigned to prophylaxis or no treatment. Febrile UTI's mostly occurred in the first 6 months, in 21 % of the prophylaxis group vs 35 % of the no treatment group. Although the trial showed a small significant benefit of prophylaxis, this came at the expense of non-E Coli and resistant UTI's in the prophylaxis group. Importantly, there was no difference between the groups in the incidence of new scars at 2-year follow up. The authors concluded that prophylaxis might only be of benefit in girls, for the first year only. This thought-provoking study challenged current practice and led to this narrative review, aimed at a critical appraisal of the literature on this topic.