Single screening test for neonatal cholestasis is not yet feasible from blood spots

Early detection of cholestasis improves the outcome in infants with biliary atresia and could prevent some cases of vitamin K dependent bleeding. Tandem mass spectrometry can be used to measure bile acid concentrations in the blood spots that are taken at 7-10 days for screening for PKU/hypothyroidism. On p 471 Mushtaq et al have shown that the bile acid concentrations are greatly increased in neonates destined to present with cholestatic jaundice. Unfortunately, however, there is too much overlap between the concentrations in cholestatic infants and those in normal infants for this to be used as a single test.