Transcutaneous bilirubin nomogram for predicting neonatal hyperbilirubinemia in healthy term and late-preterm Chinese infants

Abstract

Identifying infants that will develop significant hyperbilirubinemia with the risk of kernicterus, and planning appropriate follow-up strategies, is particularly challenging. In this study, 36,921 transcutaneous bilirubin (TcB) measurements were obtained from 6,035 healthy neonates (gestational age ≥ 35 weeks and birth weight ≥ 2,000 g) between January 1 and December 31, 2009. All measurements were performed with the JM-103 bilirubinometer at designated times between 0 and 168 postnatal hours. TcB percentiles were calculated and used to develop an hour-specific nomogram. The rate of increase in TcB was higher during the first 72 h of age, after which levels declined to a plateau by 72-108 h of age. We constructed a TcB nomogram by using the 40th, 75th, and 95th percentile values of TcB for every 12 h of the studied interval. The 75th percentile curve of the nomogram may be an ideal cutoff point for intensive follow-up of the neonate for hyperbilirubinemia as it carries very high sensitivity (78.7%) and negative predictive value (98.5%). The specificity (45.7%) and positive predictive value (15.5%) decreased to reach their lowest levels at the 40th percentile. Of the neonates in the high-risk zone, 167 (48.8%) infants had persistent subsequent hyperbilirubinemia post-discharge, compared with 292 (27.0%) infants in the high-intermediate-risk zone at discharge. One-hundred and seventeen (5.5%) infants in the low-intermediate-risk zone moved into the high-risk zone during follow-up. No newborn infants in the low-risk zone became high-risk during follow-up. We provide an hour-specific TcB nomogram to predict neonatal hyperbilirubinemia in healthy term and late-preterm Chinese infants.