Correlation of Capillary Tube and Transcutaneous Methods with Serum Biochemistry in Bilirubin Levels in Neonates with Jaundice

Objective: The aim of this study was to compare transcutaneous bilirubin (TcB) measurement, which is a noninvasive, easy, fast and inexpensive method in the treatment of patients with neonatal jaundice, with total serum bilirubin (TSB) measurement values, which is the standard method. Simultaneous capillary tube bilirubin values were also included in the study in terms of correlation. We investigated whether it would be safe to use TcB measurement instead of blood sampling for jaundice assessment. Materials and Methods: Between January 1, 2023 and July 1, 2023, newborns with gestational jaundice aged 37-42 weeks who were hospitalized with neonatal jaundice were enrolled in the neonatal intensive care unit of Gaziosmanpaşa University Faculty of Medicine (Tokat, Turkey). Patients with confirmed neonatal jaundice were retrospectively analyzed. Patients with antenatal or postnatal disease, ABO-Rh blood group incompatibility, and preterm-post-term neonates were excluded from the study. In addition, those who received phototherapy for the first time and did not have a history of transfusion were included in the study. Results: All 72 patients were term neonates. The mean gestational age was 37.26 weeks (range, 37-40 weeks) and the mean weight was 2789 ± 15 g (2255-4550 g). Thirty-one (43.1%) of the newborns were male. The direct Coombs test was 1+ in three newborns and 4+ in one newborn. There was a strong correlation between TcB bilirubin levels and TSB values before and after treatment (r = 0.776, p < 0.001; r = 0.773, p < 0.001, respectively). A strong correlation was observed between capillary tube bilirubin and TSB measurement values before and after treatment (r = 0.875, p < 0.001; r = 0.899, p < 0.001, respectively). Conclusion: In our study, we found a strong correlation between transcutaneous bilirubin measurement, serum bilirubin and capillary tube method performed through the ear before and after phototherapy treatment. However, due to the small size of this study, we cannot recommend the use of transcutaneous measurement alone in making treatment decisions.