Impact of ABO blood groups on the fertility of different parental pairs.

Classical works dealing with the possibility of mother-child incompatibility with regard to basic ABO blood groups give contradictory conclusions. Bioreproductive and population-genetic indicators have been studied in a sample of live births and in two pregnancy samples with different "a priori" and "a posteriori" risk assessment. The analysis points out that ABO blood groups can influence fertility of different parental pairs, and consequently--assessment of the individual pregnancy risk.