Selective interactions among Rh, ABO, and sex ratio of newborns

摘要

The hypothesis that the Rh and ABO blood systems behave like the HLA system in relation to mother-conception tolerance-rejection mechanisms was tested in 25,501 mother-infant pairs. According to this hypothesis, heterozygotes carrying a paternal gene that is not present in their mother should be better tolerated than homozygotes. Significantly moreBOinfants born toAOmothers.AOinfants born toBOmothers,Rh(+) heterozygotes born toRh(-) mothers, and less significantlyAOinfants born toOOmothers confirm the hypothesis. Fewer homozygotes occurred inRh(-) infants born toRh(+) mothers and inOinfants born to non-O mothers. Deviations from the Hardy-Weinberg equilibrium found in the ABO system were modified by the Rh and sex of the infant. These data strongly support the hypothesis that at least two feto-maternal systems influence the denstiny of pregnancies: the classical known incompatibility system which operates late in pregnancy and a new one which is based on the induction of maternal tolerance early in pregnancy: maternal tolerance seems to be better elicited by heterozygous eggs or embryos carrying a gene not present in the mother. The data also support the hypothesis that the sex ratio is influenced by feto-maternal tolerance-rejection mechanisms associated with the ABO and Rh systems.