Barrier contraception in the context of "Contraceptive pills"

Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth control only became available in the 20th century. Planning, making available, and using human birth control is called family planning. Some cultures limit or discourage access to birth control because they consider it to be morally, religiously, or politically undesirable.

The World Health Organization and United States Centers for Disease Control and Prevention provide guidance on the safety of birth control methods among women with specific medical conditions. The most effective methods of birth control are sterilization by means of vasectomy in males and tubal ligation in females, intrauterine devices (IUDs), and implantable birth control. This is followed by a number of hormone-based methods including contraceptive pills, patches, vaginal rings, and injections. Less effective methods include physical barriers such as condoms, diaphragms and fertility awareness methods. The least effective methods are spermicides and withdrawal by the male before ejaculation. Sterilization, while highly effective, is not usually reversible; all other methods are reversible, most immediately upon stopping them. Safe sex practices, such as with the use of condoms or female condoms, can also help prevent sexually transmitted infections. Other birth control methods do not protect against sexually transmitted infections. Emergency birth control can prevent pregnancy if taken within 72 to 120 hours after unprotected sex. Some argue not having sex is also a form of birth control, but abstinence-only sex education may increase teenage pregnancies if offered without birth control education, due to non-compliance.

The cervical cap is a form of barrier contraception. A cervical cap fits over the cervix and blocks sperm from entering the uterus through the external orifice of the uterus, called the os.

A condom is a sheath-shaped barrier device used during sexual intercourse to reduce the probability of pregnancy or a sexually transmitted infection (STI). There are both external condoms, also called male condoms, and internal (female) condoms.

The external condom is rolled onto an erect penis before intercourse and works by forming a physical barrier which limits skin-to-skin contact, exposure to fluids, and blocks semen from entering the body of a sexual partner. External condoms are typically made from latex and, less commonly, from polyurethane, polyisoprene, or lamb intestine. External condoms have the advantages of ease of use, ease of access, and few side effects. Individuals with latex allergy should use condoms made from a material other than latex, such as polyurethane. Internal condoms are typically made from polyurethane and may be used multiple times.

The diaphragm is a barrier method of birth control. It is moderately effective, with a one-year failure rate of around 12% with typical use. It is placed over the cervix with spermicide before sex and left in place for at least six hours after sex. Fitting by a healthcare provider is generally required.

Side effects are usually very few. Use may increase the risk of bacterial vaginosis and urinary tract infections. If left in the vagina for more than 24 hours toxic shock syndrome may occur. While use may decrease the risk of sexually transmitted infections, it is not very effective at doing so. There are a number of types of diaphragms with different rim and spring designs. They may be made from latex, silicone, or natural rubber. They work by blocking access to and holding spermicide near the cervix.

The contraceptive sponge is a contraceptive which combines barrier and spermicidal methods to prevent conception. Sponges work in two ways. First, the sponge is inserted into the vagina, so it can cover the cervix and prevent any sperm from entering the uterus. Secondly, the sponge contains spermicide.