Is omitting post urinary-tract-infection renal ultrasound safe after normal antenatal ultrasound? An observational study.

Abstract

Guidelines recommend obtaining a renal ultrasonogram (RUS) for young children after a first urinary tract infection (UTI). The aim of the current study was to assess the concordance of prenatal and post-UTI RUS findings in children with a first simple UTI. This was a prospective study and included all children aged 5 years or younger who were hospitalised with a first simple UTI (determined as clinical response and normalisation of temperature within 48 h on initiation of antibacterial therapy with no complications). Data were collected from each child regarding the results of prenatal and post-UTI RUS. Overall, 250 children were included in the study and the results of late-pregnancy and post-UTI RUS were available for 84% (n = 209). Complete concordance between the two RUS was demonstrated in 96% (n = 201). The predictive value of normal antenatal to normal post-UTI RUS was 96% (95% CI: 93% to 99%). These results include four children with mild transient pelvic dilatation. In eight children in whom renal anomalies were demonstrated only in post-UTI RUS, the influence of these anomalies on the children's management was negligible. Prenatal-RUS have been performed in most children <5 years old hospitalised with a first simple UTI. Concordance with post-infection tests is very high. Findings which appear only in post-infectious RUS usually have negligible effects on children's management. Thus, in such children with normal antenatal RUS omitting post-UTI RUS could be considered.