Poggiali IV, et al. - In a cohort of 162 children with congenital solitary functioning kidney (SFK), researchers investigated risk factors for renal injury and developed a predictive model using Cox proportional hazards model in this retrospective study. They assessed primary endpoint, which was time until the occurrence of a composite event of renal injury, which included proteinuria, hypertension, and chronic kidney disease (CKD). Among participants, 132 (81.5%) presented multicystic dysplastic kidney, 20 (12.3%) renal hypodysplasia, and 10 (6.2%) unilateral renal agenesis. Persistent proteinuria was detected in 10 (6.2%), hypertension in 11 (6.8%), CKD stage ≥ 3 in 9 (5.6%), and the composite outcome in 18 (11%) of 162 patients included in the analysis. Creatinine, recurrent urinary tract infection (UTI), and contralateral renal length at admission were identified as the independent predictors of the composite event after adjustment by the Cox model. For most of infants with congenital SFK, an overall low risk of renal injury was reported. A subgroup of patients with an increased risk of renal injury over time was identified by the proposed prediction model.