Sonographic temporary nephromegaly in children during the initial febrile urinary tract infection is a significant prognostic factor for recurrent infection

Abstract

Abstract There is no available data on the relationship between sonographic temporary nephromegaly in children with the initial episode of febrile urinary tract infection (fUTI) and recurrent fUTI, with a focus on whether nephromegaly is temporary or not. A multicenter retrospective cohort study on children who underwent renal ultrasound during initial fUTI was conducted between 2013 and 2020. Sonographic temporary nephromegaly is defined as increased renal length during initial fUTI following normal length of a kidney after completion of antibiotic treatment. This study included 343 children. In comparison to children without sonographic temporary nephromegaly (n = 307), duration of fever and intravenous antibiotics were significantly longer, and the level of serum CRP, creatinine and the proportion of children had recurrent fUTI were significantly higher in those with sonographic temporary nephromegaly (n = 36). In an additional analysis of 100 patients receiving voiding cystourethrography, Logistic regression model confirmed that vesicoureteral reflux (VUR) was significantly correlated with temporary nephromegaly and recurrence. The indication receiving cystourethrography in 9 of 16 with VUR who had temporary nephromegaly was recurrent fUTI. Our results suggest that sonographic temporary nephromegaly on initial infection could be a predictive factor for recurrence and VUR, and children with this factor could detect VUR before recurrence.