The completed reproductive performances of 161 couples selected before marriage and classified by ABO blood group.

Abstract

SummaryOne hundred and sixty‐one engaged white couples, resident in the eastern United States, were blood grouped and, after about 18 years, supplied detailed information on their reproductive history. After classifying the couples by ABO mating type, the possible effect of blood groups on (1) number of pregnancies, (2) number of livebirths, (3) number of stillbirths, (4) number of spontaneous abortions, and (5) interval between marriage and birth of first child was explored. No differences between incompatible (i.e. the husband has A and/or B agglutinogen which is lacking in the wife) and compatible matings were found which were significant at the 0–05 level. However, for the proportion of births which were stillbirths, the probability of the difference between incompatible and compatible matings is 0–0588, the proportion being over three times as high in incompatible matings. These findings and other aspects of the data are discussed. An appendix describing each couple is given.