An age difference between sexual partners is a social norm in most societies; typically, the man is older than the woman. The acceptability of unions in which the husband is considerably older than his wife is more variable, although relatively large age differences are found in patriarchal societies. Large age gaps are often accompanied by differences in maturity, life experiences, social position and financial resources, which may make relationships inherently unequal and a source of risk for women's health.1-5 For instance, asymmetries in age, education and economic circumstances compromise women's ability to negotiate safer sexual behavior. [1][2][3][6][7][8] The studies that have examined associations between partners' age differences and contraceptive behavior have concentrated on adolescent females' nonmarital relationships and on whether protection was used against STIs (especially HIV). [1][2][3][4][7][8][9][10][11][12][13][14][15][16][17] The emphasis on adolescents and on nonmarital relationships may divert attention from more common age asymmetries and from the risks that may exist in such relationships. For instance, age differences in marital relationships are usually of little public interest, unlike situations involving unmarried adolescents. Furthermore, there is the need to examine the role that contraceptive use may play in preventing unintended pregnancy in age-asymmetric relationships, given that contraception has been found to be an effective means of fertility control for various health, economic and social reasons.
18Examination of age differences between marital partners is of particular importance in Sub-Saharan Africa, where, as a result of gender imbalances and cultural influences, males are frequently in charge of what happens (or does not happen) within relationships, including sexual interactions and decisions regarding family size and contraceptive use. The limited decision-making power of women in this setting often impedes their ability to achieve their fertility goals. [19][20][21][22][23][24][25][26] Moreover, in a patriarchal context, pronatal views tend to be stronger among men than among women, and husbands' real or perceived opposition to family planning may prevent wives who want to delay or stop childbearing from using contraceptives.