Newborn Direct or Conjugated Bilirubin Measurements As a Potential Screen for Biliary Atresia.

OBJECTIVES

Although screening for biliary atresia (BA) is associated with improved outcomes, no screening program currently exists in the United States. In this study, we explore the possibility of a screening strategy based on newborn direct or conjugated bilirubin (DB or CB) measurements. Our objective is to estimate testing's sensitivity and specificity for BA.

METHODS

Two groups were examined retrospectively. For sensitivity calculations, a BA group consisting of infants born between January 2011 and December 2014, diagnosed with BA, and cared for at a pediatric gastroenterology referral center was examined. For specificity calculations, a non-BA group that comprised of infants born between June 2009 and August 2011 in a hospital with a policy of checking newborn bilirubin concentrations was studied.

RESULTS

All 35 infants with newborn DB or CB measurements in the BA group had elevated concentrations, translating to a sensitivity of 100% (95% CI 87.7-100). In the non-BA group, 8936 of 9102 infants had DB concentrations within the laboratory's reference interval, translating to a specificity of 98.2% (95% CI 97.9-98.4). Three methods-calculating direct:total bilirubin ratios, using 99% reference intervals, and repeat testing-changed specificity to different degrees.

CONCLUSIONS

Newborn DB or CB measurements may have a high sensitivity and specificity for BA. Specificity can be further improved by using 99% reference intervals and/or repeat testing. Our findings can serve as the foundation for larger prospective studies, to determine whether newborn DB or CB measurements can be an effective screening strategy for BA.