Relationship between Transcutaneous and Serum Bilirubin in Preterm and Term Neonates before and during Phototherapy

Background Neonatal jaundice is a common condition. Total serum bilirubin (TSB) measuring is standard for bilirubin testing, while transcutaneous bilirubin (TcB) is an alternative method. We aimed to evaluate the correlation between TSB and TcB in term and preterm neonates. Materials and Methods This prospective cross-sectional study was conducted to on 93 term and preterm neonates in Fatemieh Hospital in 2018, Hamadan, Iran. The samples were categorized into two groups, including term and preterm icteric neonates. Neonates were evaluated to determine the necessity of bilirubin estimation with TSB measurement. After the confirmation of jaundice, the blood samples obtained were sent to the laboratory for bilirubin estimation, and at the same time, the TcB measurement was performed by the bilirubinometer. Selectra X-L was utilized by which the blood samples were analyzed through the dichloroanilin method. The Pearson correlation coefficient was used to evaluate the relationship and stringency of the correlation between the approaches. Results In general, 61% and 38% of neonates were boys and girls, respectively. Before phototherapy, the TSB values were lower than TcB estimations in term and preterm neonates. The estimated Pearson correlation coefficients were obtained at r=0.729 (P<0.001), and r=0.802 (P<0.001) in term and preterm neonates, respectively. After phototherapy, contrary to the obtained results before phototherapy, the TSB concentration was higher than TcB concentrations. The difference between the measured values of the two approaches was more significant in term neonates. The Pearson correlation coefficient estimations were r=0.804 (P<0.001), and r=0.901 (P<0.001) in term and preterm neonates, respectively. Conclusion Based on the results, there was a significant correlation between the values of TSB and TcB in term and preterm neonates.