Guidelines for urinary tract infections and antenatal hydronephrosis should be gender specific

Aim Febrile urinary tract infections (UTIs) may be associated with long-term renal damage. Our goal was to identify risk factors for future UTIs in children who had voiding cystourethrography (VCUG) as a part of an antenatal hydronephrosis (ANH) assessment or after a febrile UTI. Methods We conducted a cohort study based on the medical records of children aged 0-24 months who underwent a VCUG between January 2004 and December 2011 and had at least six months of follow-up. The incidence of future UTIs was assessed. Results We included 285 children: 176 had a primary UTI and 109 had ANH. We recorded 28 UTIs during the follow-up period, and the risk was 12.5% after a primary UTI and 5.5% after an ANH (p = 0.049). Multivariate analysis showed no risk difference was found between the groups. Females had a greater risk of febrile UTIs (hazard ratio 3.3, 95% confidence interval 1.03-9.2, p = 0.04), but the UTI risk did not differ between children with or without VURs. Conclusion Female infants were at greater risk of febrile UTIs, regardless of the presence of VUR, VUR degree, ANH or a previous UTI. Clinical guidelines for UTI and ANH assessment should preferably be gender specific.