Polygyny and fertility in Sub-Saharan Africa.

The incidence of polygyny, its effect on fertility, and its future in sub-Saharan Africa are discussed from results of the World Fertility Surveys. Polygyny, marriage in which husbands have more than 1 wife, is frequent in most of southern West Africa and western Central Africa. The proportion of men in polygynous marriages ranged form 9% in Lesotho to 48% in Senegal. In Kenya and the Ivory Cast, wives in polygynous unions have on average 1 child less than those in monogamous unions. Fertility in polygynous marriages may decreased by separate residences, age differences, subfecundity of some wives, possibly higher prevalence of sexually transmitted disease and the stricter observance in these societies of postpartum abstinence and prolonged lactation. Contrary to expectations based on social changes in Africa, the incidence of polygyny is apparently increasing, although no retrospective data were collected b the Fertility Surveys. Future fertility trends in these areas are expected to remain high, even if age at marriage for women rises, because of lessened adherence to taboos of sexual abstinence, with continued lack of contraception.