We constructed a transcutaneous bilirubin (TcB) nomogram to represent major sectors of the Israeli population. We studied the risk of hyperbilirubinemia, defined as meeting the requirements for phototherapy, per percentile risk category.STUDY DESIGN:
Newborns ≥ 36 weeks gestation were tested daily for TcB, using Drager JM-103 devices, during birth hospitalization. A nomogram was constructed and divided into four risk groups and validated by calculating the need for phototherapy for each group.RESULTS:
A total of 3303 measurements were performed on 1059 consecutive newborns including Ashkenazi, Sephardic and mixed Ashkenazi/Sephardic Jews, Arab and Ethiopian Jewish. Phototherapy risk increased progressively and more than 100-fold, from 0/225 in the < 40th percentile group through 27/120 (22.5%) for those >95th percentile (relative risk (95% confidence interval) 102 (6 to 1669) for those > 95th percentile compared with those < 40th percentile). The optimal risk for discriminating the need for phototherapy was > 75th percentile (sensitivity 93.33, specificity 59.47).CONCLUSION:
The risk of significant hyperbilirubinemia increased progressively with increasing percentile. Newborns >75th percentile groups are at high risk for phototherapy and should be closely monitored.