Condom: The condom, a latex or natural-membrane sheath that fits over the erect penis, is a physical barrier to conception. The newly introduced female condom, which combines a diaphragm with a latex liner extending the length of the vagina, serves the same purpose. During ejaculation, both condoms prevent semen from entering the vagina.
One great advantage of latex condoms is that they offer a measure of protection not just against pregnancy, but also against sexually transmitted diseases such as AIDS, hepatitis B, gonorrhea, syphilis, chlamydia, herpes, and genital warts.
What about disadvantages? Occasionally a condom will break, tear, or slip during sex, allowing sperm-laden semen to spill into the vagina (backup protection with a spermicide can be of value here). Also, some men are reluctant to use a condom, claiming it forces an interruption of intercourse or dulls sexual sensation. Couples who rely on condoms alone are at a two to 12 percent risk of accidental pregnancy.
Diaphragm or Cervical Cap: Barrier devices worn by women include the diaphragm, a soft, shallow, rubber cup, and the cervical cap, a small, deep, latex cup shaped like a thimble. After smearing the inside of the diaphragm or cap with contraceptive jelly or cream, the woman inserts the device into her vagina and positions it over her cervix, the opening to her uterus. For the device to be effective she must keep it in place during intercourse and for eight hours afterward.
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The Diaphragm: A Barrier Method for Women
Stretched across a flexible wire hoop, this shallow rubber cup fits over the cervix, blocking access to the fallopian tubes and the mature egg they may harbor. The device can be inserted prior to love-making, and should be left in place for eight hours afterward. It is usually fitted individually to the woman's vaginal cavity. |
A diaphragm or cap offers women the advantage of having personal control over contraception. In addition, it can be positioned in advance and need not interrupt love-making. The diaphragm also reduces the risk of pelvic inflammatory disease and certain venereal diseases. And both diaphragm and cap are reusable.
However, as with the condom, these devices do require some preparedness and advance planning. Hence, for women relying on this approach, the risk of accidental pregnancy is six percent to 18 percent.
Spermicides: Chemical barriers to conception include spermicidal (sperm-killing) cream, jelly, and foam. These products are measured into an applicator and inserted into the vagina shortly before intercourse. The contraceptive suppository, which is inserted into the vagina and allowed to dissolve, works on the same principle, and provides protection against pregnancy for roughly an hour. The disposable contraceptive sponge contains a spermicide that becomes active when moistened. Placed against the woman's cervix, it protects against pregnancy for up to 24 hours.
An important advantage of spermicidal chemicals is that they kill not just sperm but also certain microbes, possibly including the AIDS virus. However, they do have drawbacks. Certain brands, in certain people, can cause skin or mucous membrane irritation. And because they taste bad, they can interfere with oral sex. Women who use a spermicide as their sole means of contraception have a three to 21 percent risk of accidental pregnancy.
Combinations: It's worth noting that the combination of a condom for the man plus a spermicide for the woman offers excellent protection against both pregnancy and many sexually transmitted diseases. The condom-plus-spermicide combination is the logical form of contraception for anyone who has several sexual partners, or whose sexual partner(s) might be infected with the AIDS virus or some other sexually transmitted microbe.