Comparison of the accuracy of transcutaneous bilirubin measurements from different sites before and after phototherapy in term and preterm newborn infants

Objective: Serum bilirubin measurement is a gold standard method in determining neonatal hyperbilirubinemia, but it is a painful and invasive procedure. It has been shown that the screening for newborn jaundice can be performed easily, in a shorter time, and non-invasively, reliably by transcutaneous bilirubin (TcB) measurement. The aim of this study is to determine the most suitable site for TcB measurement by comparing TcB levels measured from the sternum, abdomen, interscapular and gluteal sites with TSB levels before and after phototherapy. Methods: This prospective study was conducted in Muğla Training and Research Hospital, Neonatal Intensive Care Unite between August 2020 and August 2021. The neonates with a gestational age of 34-41 weeks who were admitted for phototherapy due to newborn jaundice in the first 28 days of life were included in the study. TcB levels measured from five regions (forehead, sternum, abdomen, interscapular and covered gluteal sites) before and after phototherapy were compared with TSB levels measured from venous blood. Results: 108 neonates with a mean gestational age of 37.6 ± 1.5 weeks and with a mean birth weight of 3108 ± 548 g were included in the study. Intraclass correlation coefficient (ICC) analysis showed that TcB measurement performed from the sternum before phototherapy (ICC=0.657, p<0.001) and TcB measurement from the gluteal site after phototherapy (ICC=0.619, p<0.001) had the best correlation with TSB. In late preterm infants (34-36 weeks), it was observed that TcB measurements performed from the forehead (r=0.948, p<0.001) before phototherapy and performed from the gluteal site (r=0.623, p=0.002) after phototherapy had the best correlation with TSB. Conclusion: It was concluded that TcB measurements performed from the sternum for newborn jaundice screening and performed from the covered gluteal site after phototherapy were effective and reliable. Key words: Newborn, jaundice, transcutaneous bilirubin, phototherapy, hyperbilirubinemia.