Subclinical hemolytic disease of the newborn due to anti-e

A case of subclinical hemolytic disease of the newborn resulting in reticulocytosis and positive direct and indirect antiglobulin tests in an infant both ABO- and Rh(D)-compatible with its mother is reported. The antibody was an IgG, non-complement-binding molecule present in low titer with a low avidity for the antigen, acted optimally in enzyme systems, did not manifest dosage effect, and caused slight extravascular destruction of fetal erythrocytes. Routine antibody screening of all pregnant women should be performed and neonatal cord blood specimens analyzed to avoid unexpected infant morbidity and mortality, and to characterize hemolytic disease of the newborn due to rare atypical antibodies more fully.