INCIDENCE OF ABO HEMOLYTIC-DISEASE OF THE NEWBORN IN A GROUP OF HONG-KONG BABIES WITH SEVERE NEONATAL JAUNDICE

Abstract Two methods were used to determine the incidence of ABO haemolytic disease of the newborn (ABO‐HDN) among Hong Kong Chinese infants. The first method employed the Lui elution technique to elute anti‐A, B from cord blood of Group A and B babies with a Group O mother, and set out to correlate the titration score of the eluate with the serum bilirubin of the neonates. This method proved to be a failure because of the poor correlation. The second method was mathematical. By comparing the ‘expected’ frequency of various mother‐infant ABO combinations (based on the ABO distribution of our local population) with the ‘observed’ frequency of a cohort of infants with severe neonatal jaundice, it was found that only two combinations (O‐A and O‐B mother‐infant pairs) were responsible for ABO‐HDN, for which the incidence was 1 in 5 among infants with a serum bilirubin level of 300 μmol/L or more. Copyright © 1990, Wiley Blackwell. All rights reserved