There are five barrier methods of contraception:
- male condoms
- female condoms
In each instance, the method works by keeping the sperm and egg apart. Usually, these methods have only minor side effects. The main possible side effect is an allergic reaction either to the material of the barrier or the spermicides that should be used with them. Using the methods correctly for each and every sexual intercourse gives the best protection. For many people, the prevention of sexually transmitted diseases (STDs), including HIV (human immunodeficiency virus), which leads to AIDS, is a factor in choosing a contraceptive. Only one form of birth control currently available–the latex condom, worn by the man–is considered highly effective in helping protect against HIV and other STDs. FDA has approved the marketing of male condoms made from polyurethane as also effective in preventing STDs, including HIV. However, at press time, they were not yet being sold in this country. Reality Female Condom, made from polyurethane, may give limited protection against STDs but has not been proven as effective as male latex condoms. People who use another form of birth control but who also want a highly effective way to reduce their STD risks, should also use a latex condom for every sex act, from start to finish. Barrier methods, which work by keeping the sperm and egg apart, usually have only minor side effects. In addition to the possible allergic reactions or irritation common to all barrier methods, there have been some reports of bladder infections with this method. As with the contraceptive sponge, TSS is an extremely rare side effect.
A male condom is a sheath that covers the penis during sex. Condoms on the market at press time were made of either latex rubber or natural skin (also called “lambskin” but actually made from sheep intestines). Of these two types, only latex condoms have been shown to be highly effective in helping to prevent STDs. Latex provides a good barrier to even small viruses such as human immunodeficiency virus and hepatitis B. Each condom can only be used once. Condoms have a birth control failure rate of about 15%. Most of the failures can be traced to improper use. Some condoms have spermicide added. This may give some additional contraceptive protection. Vaginal spermicides may also be added before sexual intercourse. Some condoms have lubricants added. These do not improve birth control or STD protection. Non-oil-based lubricants can also be used with condoms. However, oil-based lubricants such as petroleum jelly (Vaseline) should not be used because they weaken the latex. Condoms are available without a prescription.
The Reality Female Condom consists of a lubricated polyurethane sheath with a flexible polyurethane ring on each end. One ring is inserted into the vagina much like a diaphragm, while the other remains outside, partially covering the labia. The female condom may offer some protection against STDs, but for highly effective protection, male latex condoms must be used. (The female condom should not be used at the same time as the male condom because they will not both stay in place.) In a 6-month trial, the pregnancy rate for the Reality Female Condom was about 13%. The estimated yearly failure rate ranges from 21% to 26%. This means that about 1 in 4 women who use Reality may become pregnant during a year.
The contraceptive sponge is made of white polyurethane foam. The sponge, shaped like a small doughnut, contains the spermicide nonoxynol-9. Like the diaphragm, it is inserted into the vagina to cover the cervix during and after intercourse. It does not require fitting by a health professional and is available without prescription. It is to be used only once and then discarded. The failure rate is between 18% and 28%. An extremely rare side effect is toxic shock syndrome (TSS), a potentially fatal infection caused by a strain of the bacterium Staphylococcus aureus and more commonly associated with tampon use.
The diaphragm is a flexible rubber disk with a rigid rim. Diaphragms range in size from 2 to 4 inches in diameter and are designed to cover the cervix during and after intercourse so that sperm cannot reach the uterus. Spermicidal jelly or cream must be placed inside the diaphragm for it to be effective. The diaphragm must be fitted by a health professional and the correct size prescribed to ensure a snug seal with the vaginal wall. If intercourse is repeated, additional spermicide should be added with the diaphragm still in place. The diaphragm should be left in place for at least six hours after intercourse. The diaphragm used with spermicide has a failure rate of from 6% to 18%.