Renal ultrasonography findings are associated with urinary tract infection in neonates with asymptomatic hyperbilirubinemia.

OBJECTIVE: This study evaluated clinical, laboratory, and ultrasonographic factors associated with UTI in neonates hospitalized for unexplained hyperbilirubinemia. STUDY DESIGN: This retrospective cohort study included 96 neonates hospitalized for unexplained hyperbilirubinemia requiring phototherapy. UTI was defined by pyuria (>5 WBC/high-power field) and growth of a single uropathogen (≥50,000 CFU/mL) from catheterized urine samples. Neonates were classified as UTI-positive (n = 30) or UTI-negative (n = 66). Demographic characteristics, bilirubin levels, inflammatory markers, and renal ultrasonography findings were compared. RESULTS: UTI was diagnosed in 31.2% of neonates. Bilirubin levels, white blood cell counts, and C- reactive protein concentrations did not differ between groups. Pathological renal ultrasonography findings were significantly more frequent in the UTI group and were independently associated with UTI (odds ratio 4.62; 95% CI 1.39-15.40). CONCLUSION: Renal ultrasonography findings are strongly associated with UTI in hospitalized neonates with unexplained hyperbilirubinemia and may serve as a useful adjunctive evaluation tool in this high-risk population.