Predicting significant hyperbilirubinemia using birth weight
- Assiamira Ferrara (assiamira.ferrara{at}kp.org)
Abstract
Background: A recent study proposed a risk factor scoring system for prediction of hyperbilirubinemia that assigned increased risk to infants of higher birth weight. Our large, retrospective cohort analysis investigated this novel finding.
Methods: Our retrospective cohort study analyzed 105,384 newborns ≥2000 g and ≥36 weeks and reports the effect of higher birth weight on total serum bilirubin (TSB) ≥342 ìmol/L using logistic regression to control for gestational age, scalp injury diagnosis, maternal diabetes, method of delivery and other confounders.
Results: The odds ratio for the effect of an additional 500g of birth weight on TSB ≥342 ìmol/L declined with increasing gestational age from 1.55 (1.28-1.87) at 36 weeks, to 1.30 (1.12-1.50) at 37 weeks and 1.14 (1.01-1.29) at 38 weeks. There was no association for infants ≥39 weeks.
Conclusion: Higher birth weight predicts TSB ≥342 ìmol/L in 36-38 week infants, but not in infants ≥39 weeks. Further research should explore the causal mechanism for the association in less-mature infants.
