Male condoms are thin sheaths of latex (rubber), polyurethane (plastic), or animal tissue that are rolled onto an erect penis immediately prior to intercourse. They are commonly called "safes" or "rubbers." Female condoms are made of polyurethane, and are inserted into the vaginal canal before sexual relations. The open end covers the outside of the vagina, and the closed ring fits over the cervix (opening into the uterus). Both types of condoms collect the male semen at ejaculation (the release of semen during intercourse), and thus act as a barrier to fertilization. Condoms also perform as barriers to the exchange of bodily fluids between persons involved in a sexual act, whether male-to-male, male-to-female, or female-to-female contact.

Both male and female condoms are used to prevent pregnancy and to protect against acquired immunodeficiency syndrome (AIDS), genital warts and other sexually transmitted diseases. To accomplish these goals, the condom must...