[Reproductive compensation in human populations]

Reproductive compensation was studied in Russian (family planning) and Middle-Asian (with natural reproduction) urban and rural populations. Questionnaires were used describing postreproductive-age women having at least one pregnancy. The presence of reproductive compensation in a population was identified by comparison of two groups: "loaded" and "unloaded" by values of total and effective fertility. Families with excessive (compared with the mean population value) pregnancy outcome failure (spontaneous abortions, stillbirths, preproductive-age deaths of children) were ascribed to the loaded group. Reproductive compensation was discovered in all populations studied, which indicates that this phenomenon is wide-spread in human populations.