COMPARATIVE STUDY OF RH-D ANTIBODY TITRES OF AMNIOTIC FLUIDS AND CORRESPONDING MATERNAL SERA IN RH-D SENSITIZED PREGNANCIES

IT has been well documented that the severity of erythroblastosis foetalis resulting from maternal Rh factor sensitization is not always proportional to the titre of the mother's serum Rh isoagglutinins1-12. The titre of Rh antibodies in cord serum from Rh negative infants of Rh negative mothers is usually equal to the titre obtained in the maternal serum except for saline agglutinins13. In cases of erythroblastosis resulting from Rh sensitization, however, it is not possible to ascertain how many Rh antibodies have passed into the foetal circulation, for such antibodies are absorbed by the infant's Rh positive cells. Rh antibodies may not be demonstrable in the infant's serum except where excessive amounts (more than necessary to coat all foetal erythrocytes) have been acquired from the mother. © 1969 Nature Publishing Group.