Predicting significant hyperbilirubinaemia using birth weight
- 1Division of General Pediatrics, University of California, San Francisco, California, USA
- 2Division of Research, Kaiser Permanente Medical Care Program, Oakland, California, USA
- 3Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, Washington, USA
- 4Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA
- Dr V Flaherman, University of California, San Francisco, 3333 California St, Box 0503, San Francisco, CA 94143-0503, USA; FlahermanV{at}peds.ucsf.edu
- Accepted 13 January 2008
- Published Online First 19 February 2008
Abstract
Background: A recent study proposed a risk factor scoring system for prediction of hyperbilirubinaemia that assigned increased risk to infants of higher birth weight.
Objective: To investigate this novel finding in a large, retrospective cohort analysis.
Methods: 105 384 newborns (≥2000 g and ≥36 weeks) were analysed, and the effect of higher birth weight on total serum bilirubin (TSB) ≥342 μmol/l was reported 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 500 g of birth weight on TSB ≥342 μmol/l declined with increasing gestational age from 1.55 (95% CI 1.28 to 1.87) at 36 weeks to 1.30 (95% CI 1.12 to 1.50) at 37 weeks and 1.14 (95% CI 1.01 to 1.29) at 38 weeks. There was no association for infants ≥39 weeks.
Conclusion: Higher birth weight predicts TSB ≥342 μmol/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.
Footnotes
-
Competing interests: None.
