By the Numbers: World Birth-Control Use; September 1996; Scientific American Magazine; by Doyle; 1 Page(s)

Over the past 30 years or so, there has been a dramatic decline in world fertility rates, particularly in developing countries. Between 1960 and 1965 women in these countries averaged six births over a lifetime, but 30 years later they averaged only 3.4. In east Asia over the same period, births per woman fell 65 percent and are now below the replacement rate of 2.1 children. In other parts of Asia, births declined by about a third, whereas in Latin America, they have almost halved. In Africa, on the other hand, the drop has been only 10 percent. In the developed countries the number of births per woman declined by about 40 percent and are now below replacement level in virtually all these countries, including the U.S.

Modern contraceptive methods have played a key role in lowering fertility. Among women of reproductive age who are married (or in nonmarital unions), half now depend on such methods as female sterilization (the most popular), male sterilization, hormonal implants such as Norplant, injectibles such as Depo-Provera, intrauterine devices (IUDs), birth-control pills, condoms and diaphragms. The first four methods are almost 100 percent effective in preventing conception. Next are IUDs, followed by the pill and the male condom. Diaphragms are among the least effective. Condoms-- both the male and female type--are the only methods currently available that provide some protection against sexually transmitted diseases, such as AIDS.