Follow-up of congenital abnormalities of the kidney and urinary tract from the antenatal period to the first year of life: a retrospective study from Turkey

Purpose: This study aimed to evaluate the progression of renal function and clinical outcomes during the first year of life in infants with congenital abnormalities of the kidney and urinary tract (CAKUTs) detected via antenatal ultrasonography.Methods: This retrospective, observational cohort study included 55 infants, categorized into two groups: those with collecting system anomalies (CSAs) and those with renal parenchymal malformations (RPMs). The primary outcomes were the incidences of acute kidney injury (AKI) and chronic kidney disease (CKD) as well as the prognostic indicators linking the antenatal and postnatal periods.Results: CSAs were more common in both the antenatal and postnatal periods, with incidence rates of 54.5% and 56.4%, respectively. Hydronephrosis was the most frequently detected CAKUT type during the antenatal period (47.2%). Multicystic dysplastic kidney was the most predominant lesion in both antenatal and postnatal diagnoses within the RPM group, accounting for 38.2%. Although the incidence of AKI did not differ significantly between the two groups, CKD was more prevalent in the RPM group (P<0.05). Gestational age, presence of oligohydramnios, and several ultrasonographic findings (including loss of corticomedullary differentiation, bladder trabeculation, and cysts) were significantly associated with the development of AKI. In multivariate logistic regression analysis, loss of corticomedullary differentiation remained an independent predictor of AKI (odds ratio, 13.5; 95% confidence interval, 1.8–100.0; P=0.011).Conclusions: Loss of corticomedullary differentiation on postnatal ultrasound is an important predictor of AKI, highlighting the need to investigate its relevance during the prenatal period.