Comparative Assessment of Transcutaneous Bilirubin Versus Total Serum Bilirubin Measurements in Preterm Infants

Hyperbilirubinemia is a common condition, particularly among preterm neonates. Although transcutaneous bilirubin (TCB) measurement offers a non-invasive modality for bilirubin assessment, its diagnostic accuracy in preterm populations remains incompletely characterized. This study addresses a knowledge gap by focusing on preterm neonates between 28 and 35 weeks of gestation and evaluating the concordance between TCB and total serum bilirubin (TsB) measurements.

A prospective cohort study was conducted at a tertiary care academic medical center between April 2023 and February 2024. The cohort included preterm neonates (≤35 weeks of gestation) admitted to the Neonatal Intensive Care Unit (NICU). TCB measurements were obtained within two hours of each TSB sampling using BiliCare™, a transcutaneous bilirubin meter. Statistical analyses, including Bland-Altman plots and Lin's concordance correlation coefficient (CCC), were used to evaluate the agreement between the two methods, TCB and TsB.

A total of 300 paired bilirubin measurements from preterm neonates (gestational age range: 24-35 weeks) were analyzed. TCB and TsB demonstrated substantial concordance, with CCC values of 0.88 for neonates born at ≤28 weeks, 0.92 for those born at 29-32 weeks, and 0.95 for those born at>32 weeks. Minor variability and systematic bias were noted. The limits of agreement across all groups fell within a clinically acceptable range of ±4 mg/dL.

TCB represents a viable non-invasive alternative to TsB for bilirubin monitoring in preterm neonates with hyperbilirubinemia, potentially minimizing the need for frequent invasive blood sampling. However, the observed variability across gestational age subgroups underlines the need for cautious interpretation, particularly in subpopulations where discrepancies may occur. Further investigations are warranted to optimize the application of TCB in larger neonatal cohorts.