ADOLESCENT TRANSITION TO COITUS AND PREMARITAL CHILDBEARING IN SUDAN: A BIOSOCIAL CONTEXT

This paper examines the biosocial basis of premarital sexual and reproductive behaviour among women in Sudan. It applies Udry's biosocial perspective, which attempts to reconcile the biological and sociological models of premarital sexual and reproductive behaviour. World Fertility Survey (WFS) data were used to study premarital first motherhood. Early puberty was found to be paramount in determining childbearing in a separate biological model, but also in a biosocial model constructed to take account of social controls. This finding suggests that social controls do not influence the biological predisposition to premarital sexual behaviour. However, given the limitations of the WFS data, conclusive evidence must await a more appropriately designed study of reproductive behaviour in Sudan.

The end of fertility: age, fecundity and fecundability in women

SummaryOnset of capacity for childbearing in women is dated biologically by menarche, although actual onset may be delayed. The end of childbearing is less understood but recent demographic and biological research on fertility at older ages is clarifying the end of fertility.The demographic view of declining fertility with age is based on age-specific fertility in natural fertility populations, artificial insemination and pregnancy rates by age and World Fertility Survey data. New data from the Demographic and Health Surveys on exposure to the risk of pregnancy shows that whereas older women biologically need longer exposure to pregnancy, exposure declines on behavioural grounds such as duration of marriage. Actual fecundity is obscured by factors of fecundability. Recent research on medically assisted conception is adding to the understanding of declining fecundity with age, especially the relative contributions of endometrial and ovarian ageing.This paper reviews the available information on declining fertility with age and discusses the implications of the extension of fertility through new medical technologies.

The Influence of Rural-Urban Migration on Migrant's Fertility Behavior in Cameroon

An autoregressive model has been applied to the 1978 Cameroon World Fertility Survey data to test the fertility adaptation hypothesis of rural-urban migration. The fertility differential between rural-urban migrants and rural stayers is very small in Cameroon when compared with that of Korea and Mexico. However, the lack of fertility differentials between rural-urban migrants and rural stayers which are the result of the unique cultural and biosocial parameters of African fertility does not imply a weak fertility adaptation effect.