Contraceptives
Each method of birth control has a failure rate--an inability to prevent pregnancy over a one-year period. Sometimes the failure rate is due to the method and sometimes it is due to human error, such as incorrect use or not using it at all. Each method has possible side effects, some minor and some serious. Some methods require lifestyle modifications, such as remembering to use the method with each and every sexual intercourse. Some cannot be used by individuals with certain medical problems. Most forms of contraception can be split into two groups: the physical, or barrier methods, and the chemical methods. Different forms of contraception can also be combined.
There are five barrier methods of contraception: male condoms, female condoms, diaphragm, sponge, and cervical cap. 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.
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.