The predictive significance of umbilical cord bilirubin and bilirubin/albumin ratio for neonatal jaundice in healthy term newborns

The aim of this study is to determine the value of the questions asked in routine follow-up, the cord blood bilirubin (CBB) and bilirubin/albumin (B/A) ratio in estimating the risk of developing hyperbilirubinemia. Term and healthy 217 newborns whose CBB and albumin could be obtained and whose needed to be measured bilirubin level at the 24thand 72nd hours of life were included. Nutrition, sex and nationality, consanguinity between parents, jaundice in the sibling (s), mother's medications were questioned. CBB and albumin, serum total bilirubin (STB), serum albumin and transcutaneous bilirubin (TcB) at the 24th and 72nd hours of life, were recorded. CBB and cord B/A ratio, STB and serum B/A ratio, and TcB at the 24th and 72nd hours were found to be higher in the babies who received the phototherapy (p < 0.001 for all). The moderate positive correlation (correlation coefficient 0.383) at the 24th hour and strong positive correlation (correlation coefficient 0.759) at the 72nd hour between STB and TcB measurements was detected. In estimating the need for phototherapy the sensitivity and specificity of CBB were 74.2% and 56.5%, the sensitivity and specifity of cord B/A was 74.2%, and 61.8%. The cut-off value of CBB in estimating the need for phototherapy is 1.8, and the cut-off value of the cord B/A ratio is 0.56. When the cut-off value is 1.8 for the CCB and the cord B/A ratio is 0.56, the positive predictive values are low, but the negative predictive values are significantly high (92.9% and 93.5%, respectively) in determining the need for phototherapy. CBB and B/A ratio are important in predicting the possibility of indirect hyperbilirubinemia (IHB) development. Babies should be followed closely in terms of IHB development when their CBB value is 1.8 mg/dL and above, and the cord blood B/A ratio is 0.56 and above.