Validation of transcutaneous bilirubin nomogram in identifying neonates not at risk of hyperbilirubinaemia: a prospective, observational, multicenter study

Background: Transcutaneous bilirubin (TcB) measurement is widely used as screening for neonatal hyperbilirubinaemia.

Aims: To prospectively validate TcB measurement using hour-specific nomogram in identifying newborn infants not at risk for severe hyperbilirubinaemia.

Study design: prospective, observational, multicenter.

Subjects: 2167 term and late preterm infants born in 5 neonatal units in the Lazio region of Italy.

Methods: All neonates had simultaneous TcB and total serum bilirubin (TSB) measurements, when jaundice appeared and/or before hospital discharge. TcB and TSB values were plotted on a percentile-based hour-specific transcutaneous nomogram previously developed, to identify the safe percentile able to predict subsequent significant hyperbilirubinaemia defined as serum bilirubin >17 mg/dL or need for phototherapy.

Results: Fifty-five babies (2.5%) developed significant hyperbilirubinaemia. The 50th percentile of our nomogram was able to identify all babies who were at risk of significant hyperbilirubinaemia, but with a high false positive rate. Using the 75th percentile, two false negatives reduced sensitivity in the first 48 hours but we were able to detect all babies at risk after the 48th hour of age.

Conclusions: This study demonstrates that the 75th percentile of our TcB nomogram is able to exclude any subsequent severe hyperbilirubinaemia from 48 h of life ahead.