Recent experience with and future directions of contraceptive implants and injectable contraceptives.

Subdermal implantable contraception has been the most important addition to contraceptive technology in the past 2 decades. The Norplant system is only the first of a new family of long acting methods of high effectiveness, high acceptability, and prompt reversibility. The main advantage of the second generation implant systems, to be available soon, is the reduction in the number of implants, which greatly facilitates insertion and removal. However, great improvement in bleeding control is not to be expected. Large and carefully designed epidemiological studies have contributed to clear the main objections to the US Food and Drug Administration (FDA) approval of depot medroxyprogesterone acetate (DMPA) as an injectable contraceptive. New progestin-only, long acting injectables are being tested, but significant improvements over existing methods are difficult to foresee, although every alternative is welcome. Monthly combined injectables have been in great demand, at least in China and Latin America, because of better bleeding control. Improved combined monthly injectables, less estrogenic and more progestin dominated, have been developed and are being introduced in several countries and should soon replace the old monthly injectables. Contraceptive implants and injectables have shown to be an important addition to the contraceptive options available to women throughout both the developing and developed world.