Israel transcutaneous bilirubin nomogram predicts significant hyperbilirubinemia

Abstract

Objective: 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.