Large Ureterocele Associated With a Duplex Collecting System in an Infant: A Case Report.

Ureteroceles, especially large or ectopic ones in duplex systems, present significant management challenges in neonates due to the risk of urinary tract infections (UTIs) and potential for renal scarring. We present the case of a neonate diagnosed prenatally with a large ureterocele with associated duplex system and hydronephrosis. Postnatal management followed a conservative initial approach with continuous antibiotic prophylaxis (CAP) using amoxicillin, in alignment with the AAP guidelines. The patient remained asymptomatic while awaiting definitive surgical intervention. This case highlights the efficacy of standardized urinary tract dilation (UTD) grading and the role of CAP in preventing febrile UTIs while bridging patients toward surgical decompression. However, the efficacy of CAP cannot be generalized from this case report.