Newborn screening for ABO hemolytic disease

Confusion still exists regarding the true incidence of ABO hemolytic disease and the significance of the various laboratory investigations commonly employed in its evaluation. With such imprecision in diagnosis, early hospital discharge of newborns can be a potential problem. To evaluate the usefulness of more extensive screening than commonly employed and to identify possible indicators of severity, a pilot study of cord blood screening was undertaken. In the study, 1391 cord blood specimens were tested for type, Rh, direct antiglobulin test (DAT), indirect Coombs, and total and indirect bilirubin. Of the specimens, 53.3 percent were type A, B, or AB, and 19.3 percent of both A and B infants and 7 percent of AB infants had immune antibodies in their sera. DAT was neither diagnostic nor predictive of severity. DAT was negative in 48 percent of infants with serum antibody and did not correlate with cord blood or peak serum bilirubin levels. The cord blood bilirubin also was not diagnostic of hemolytic disease but was moderately predictive of peak bilirubin levels. The data do not support the use of any routine screening tests in the management of ABO hemolytic disease.