Relationship between infectious screening and early unconjugated hyperbilirubinemia in well-appearing neonates

Neonatal hyperbilirubinemia (NH) may be the initial and solitary sign of infectious condition in neonates. This retrospective cohort study aims to evaluate the risk of sepsis or urinary tract infection in well-appearing infants with NH below 7 days old.

All neonates (n = 8779) born in Taipei Veterans General Hospital from 2013 to 2017 were evaluated retrospectively. A total of 2523 initially well-appearing babies were admitted because of NH. After being hospitalized, patients were categorized into two groups according to the initial transcutaneous bilirubin (TCB) level. Infectious screening results, which include C-reactive protein (CRP), differential count, blood culture, urinalysis, and urine culture, were analyzed.

Regarding CRP, 2.7% (18/667) of neonates with NH had elevated CRP (≥1 mg/dL). Among 547 blood cultures, eight were positive, with 0.4% (2/547) non-coagulase-negative staphylococcus (CoNS) bacteremia and 1.1% (6/547) CoNS bacteremia. In urinalysis, 16.6% (182/1094) of NH neonates had pyuria, and 6.7% (25/372) had positive urine cultures. NH with a higher initial TCB level was related to an increased chance of elevated CRP (4.7% vs. 1.5%, odds ratio: 3.29, p = 0.024) and pyuria (20.6% vs. 12.6%, odds ratio: 1.79, p < 0.001). The rate of positive urine culture between the higher and lower TCB groups had no significant difference (6.6% vs. 6.9%, p > 0.99). Significant bacteriuria was more common in NH neonates admitted at later age (>2 days) (4.9% vs. 11.5%, p = 0.035).

In well-appearing neonates below 7 days old, NH with a higher initial TCB is associated with an increased rate in pyuria and abnormal CRP. No difference was found in the rate of positive urine culture between higher and lower TCB levels. Significant bacteriuria was more common in older NH neonates. Septicemia is rare among well-appearing neonates with NH.