Recent developments in barrier methods of contraception

Women have used contraceptive barriers for centuries, such as leaves, to prevent pregnancy and sexually transmitted diseases (STDs). Spermicides are used with at least 3 of the 5 modern female barrier methods -- the diaphragm, the cap, and the sponge. The thin domed rubber diaphragms lie diagonally across the cervix, the vault, and part of the anterior vaginal wall. Suction holds the cervical/vault caps in place. Women must be fitted for these 2 methods before use. Women can buy a small polyurethane sponge impregnated with 1 gram of nonoxynol-9 spermicide to cover the cervix over the counter. It has a high failure rate, however, since adequate instructions for insertion are not provided. The vaginal ring is not designed to fit into 1 fixed position in the vagina, yet probably spends most of its time in the posterior fornix. The ring continuously releases the levonorgestrel or a spermicide. The recently developed vaginal shield or female sheath has promise. It is a hollow tube made of strong elastic polyurethane. Since the era of the ancient Romans and Egyptians, men have used barriers made of such diverse material as animal bladders, silk, and lamb intestine, to protect against dirt and disease or for decoration. Condoms were 1st manufactured in the 1900s and had to be washed and dried following each act of intercourse. With the increase in STDs during World War II, condom distribution to the troops became standard practice. Today condoms come in a variety of colors, lengths, and strengths. Some have been coated with the spermicide nonoxynol-9 which protects against STDs. The condom follows oral contraceptives as the most popular form of contraceptive in the United Kingdom. A 1987 television campaign to promote barrier method use in light of the AIDS epidemic backfired. For example, it implied that diaphragms and sponges protect women from HIV.