title: Contraceptive use and annual acceptors required for fertility transition: results of a projection model.
abstract: Major fertility declines in developing countries are invariably accompanied by large increases in contraceptive prevalence and in the annual number of new acceptors. This article applies a target-setting model to make hypothetical projections of trends in prevalence and number of acceptors over the course of a full fertility transition. The sensitivity of these trends to variations in proximate determinants such as the marriage pattern and the duration of lactational amenorrhea, as well as in the discontinuation rate and the method mix, are examined. It is concluded that a contraceptive prevalence of around 75 percent is needed to achieve replacement-level fertility and that variations in proximate determinants other than contraceptive prevalence have only a modest effect on this result. On the other hand, trends in new acceptors are demonstrated to be very sensitive to discontinuation rate changes. As a consequence, it is generally difficult to draw conclusions about trends in fertility from trends in acceptors.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000568:Amenorrhea / Q000209:etiology; D003267:Contraception; D003906:Developing Countries; D005260:Female; D005298:Fertility; D006801:Humans; D007774:Lactation / Q000502:physiology; D008393:Marriage; D008962:Models, Theoretical; D010342:Patient Acceptance of Health Care; D011247:Pregnancy; D013245:Sterilization, Reproductive / Q000639:trends