Postnatal outcomes and surgical management of prenatally detected unilateral congenital anomalies of the kidney and urinary tract.

Background: Congenital anomalies of the kidney and urinary tract (CAKUT) represent 15-20% of prenatally diagnosed congenital anomalies, often presenting unilaterally. This study aimed to describe sonographic features of fetuses with unilateral renal anomalies and evaluate their postnatal outcomes. Additionally, we assessed whether specific prenatal ultrasound findings predicted postnatal complications.

Methods: This was a retrospective, observational study including singleton pregnancies referred to our center from 2008 to 2023 for unilateral renal anomalies identified in second or third trimester ultrasounds. Sequential prenatal ultrasound evaluations were conducted to monitor disease progression and associated anomalies. Postnatal outcomes were retrieved from delivery records and pediatric follow-ups. Statistical analyses included Chi-square tests, t-tests, and ROC curve analysis to assess the predictive value of the antero-posterior diameter (DAP) of the renal pelvis for postnatal complications.

Results: A total of 226 cases were included: 116 (51.3%) pyelectases, 51 (22.6%) hydroureteronephroses, 48 (21.2%) multicystic kidneys, and 11 (4.9%) renal dysplasias. Diagnosis occurred at an average gestational age of 25 weeks, with 19.3% showing progression during pregnancy and 23% having associated anomalies detected during ultrasound examinations. Of 135 children with follow-up data, 47.4% required surgery, 1.5% developed hypertension, and 1.5% developed chronic kidney disease (CKD). Associated anomalies significantly correlated with unfavorable outcomes, such as need for intervention (P=0.001), risk of developing postnatal recurrent urinary infections (P=0.025), vesicoureteral reflux (P=0.001) and CKD (P=0.010). Progression during pregnancy correlated with vesicoureteral reflux (P=0.002) and development of anomalies in the contralateral kidney (P=0.012). DAP measurement did not reliably predict postnatal complications (AUC=0.590, P=0.191).

Conclusions: Unilateral renal anomalies are often associated with other congenital anomalies, influencing postnatal outcomes. DAP measurement was not a significant predictor of postnatal complications. Comprehensive prenatal ultrasound assessments are critical for guiding parental counseling, pregnancy management, and postnatal care.