Skin bilirubin nomogram for the first 96 h of life in a European normal health newborn population, obtained with multiwavelength transcutaneous bilirubinometry

Aim: Hour-specific nomogram evaluation of serum or skin bilirubin is a suitable approach for managing neonatal hyperbilirubinemia and it is recommended by American Academy of Paediatrics. We aimed to provide data about skin bilirubin levels during the natural course of hyperbilirubinemia in European healthy neonates. Methods: We enrolled 2198 healthy newborn infants (gestational age [GA] >= 35 weeks) from 24 to, 96 h of life and performed transcutaneous bilirubin (TcB) measurement, in order to draw the nomogram for 10th, 25th, 50th, 75th and 95th percentiles of skin bilirubin, both for term and near term babies. All measurements were performed with a multiwavelength transcutaneous bilirubinometer (Respironics BiliCheck (TM)), within 2 h of the designed time and data were analysed with linear and local smoother regression. Results: We described the peculiar pattern of skin bilirubin increasing rate over different time periods. Bilirubin linearly increases rapidly in the first 48 h and less rapidly from 48 to 72 h, while the increment is insignificant from 72 to 96 h. Conclusion: We provide the first data on skin bilirubin trend in a large predominantly breastfed and healthy European newborn population during the natural course of nonpathologic hyperbilirubinemia. Nomogram and increment rate of skin bilirubin are useful to identify neonates requiring closer evaluation and to plan an adequate follow-up.