Reference intervals for laboratory tests are important in the diagnosis and treatment of disease. However, due to difficulty in recruiting sufficient numbers of reference subjects, studies regarding reference intervals for biochemical analytes in neonates is lacking. The aim of this study was to compare and validate the reference intervals for 23 biochemical analytes in the cord blood of neonates. From August to December 2017, 79 consecutive neonates born at the Wonju Severance Christian Hospital (Wonju, Korea) with C-reactive protein concentration less than 0.05 mg/dL were included in this study. All of 23 biochemical analytes were measured by the cobas 8000 c702 (Roche Diagnostics, Switzerland). Mean ± 2 standard deviations (SD) were calculated if the values were normally distributed, and median and the range of 2.5-97.5 percentile were described when the values were not normally distributed. We compared the neonatal reference intervals for 23 biochemical analytes. Alkaline phosphatase and gamma glutamyl transferase showed significant differences according to sex, and direct bilirubin revealed significant differences depending on the delivery mode. These compared reference intervals of 23 biochemical analytes will be useful for clinical decision-making in the management of neonates.

Keywords: biochemical, cord blood, neonates, reference interval