The latex rubber or animal intestine condom, or contraceptive sheath, serves as a cover for the penis during coitus and prevents the deposition of semen in the vagina. The advantages of the condom are that it provides highly effective and inexpensive contraception as well as protection against sexually transmitted diseases (STDs). Some condoms now contain a spermicide, which may offer further protection against failure, particularly if the condom breaks. Given the concern about both STDs and the HIV epidemic, condom use should be a significant consideration for persons who are at risk for contracting such infections.

The condom probably is the most widely used mechanical contraceptive in the world today. Most condoms are made of latex that is 0.3-0.8 mm thick, a membrane that is impervious to both sperm and most bacterial and viral organisms that cause STDs or HIV infection. However, the less commonly used lamb’s intestine condom is not impermeable to such organisms. The failure of all condoms is due to imperfections of manufacture (about 3 per 1000); errors of technique, such as applying the condom after some semen has escaped into the vagina; and escape of semen from the condom as a result of failure to withdraw before detumescence. In overall use, failure rates with condoms range from 2-15% in the first year of use.

When greater contraceptive effectiveness is desired, a second method such as contraceptive vaginal jelly or foam should be used in conjunction with the condom. This significantly reduces the chances for condom failure due to mechanical or technical deficiencies. No association has been established between the use of vaginal contraceptives (spermicides) and the occurrence of congenital malformations if a pregnancy occurs.