Hemolytic disease of the newborn due to anti-A

Eleven cases of hemolytic disease of the newborn are described in which the only blood group antibody in the mother's serum, incompatible with the infant's cells, was anti-A. The direct antiglobulin (Coombs) test on the infant's red cells was weakly positive in 7 cases and negative in 4 cases. In every case the mother's serum displayed immune characteristics, in particular the ability to lyse A cells. Osmotic fragility was increased in 10 out of 11 cases. This finding is contrasted with those in a series of cases of hemolytic disease of the newborn due to anti-Rh.