Bodyweight loss in predicting neonatal hyperbilirubinemia 72 hours after birth in term newborn infants

Background: Severe dehydration is generally believed to be a cause of significant hyperbilirubinemia in newborn babies. This study aimed to analyze the weight loss of healthy term newborn infants at 24, 48 and 72 hours after birth to predict significant hyperbilirubinemia at 72 hours. Methods: From January 2007 to December 2008, we conducted this retrospective chart review by measuring total bilirubin (transcutaneous and serum) in 343 healthy, term newborns with a birth body weight of more than 2500 g. We then analyzed the association between body weight loss (BWL) and significant hyperbilirubinemia (total bilirubin more than 15 mg/dL) 72 hours after birth. Receiver operating characteristic curves were used to evaluate the appropriate cutoff BWL percentages on the first three days after birth for the prediction of neonatal hyperbilirubinemia 72 hours after birth. Results: A total of 115 (33.5%) neonates presented with significant hyperbilirubinemia 72 hours after birth, and the percentages of BWL on the first three days were all higher than those in the non-significant hyperbilirubinemia group (all p < 0.05). Breastfeeding was not statistically correlated with significant hyperbilirubinemia (p=0.86). To predict significant hyperbilirubinemia 72 hours after birth, receiver operating characteristic curve analysis showed that the optimum cutoff BWL percentages were 4.48% on the first day of life (sensitivity: 43%, specificity: 70%, positive likelihood ratio [LR+]: 1.43, and negative likelihood ratio [LR-]: 0.82), 7.60% on day 2 (sensitivity: 47%, specificity: 74%, LR+: 1.81, LR-: 0.72), and 8.15% on day 3 (sensitivity: 57%, specificity: 70%, LR+: 1.92, LR-: 0.61) (all p < 0.05). Conclusions: BWL on the first three days after birth may be a predisposing factor for neonatal hyperbilirubinemia, and may also serve as a helpful clinical factor to prevent significant hyperbilirubinemia 72 hours after birth. The optimal BWL cutoff percentages on the first three days after birth presented in this study may predict hyperbilirubinemia and indicate the need for supplementary feeding.