Birth control
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, 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.
In teenagers, pregnancies are at greater risk of poor outcomes. Comprehensive sex education and access to birth control decreases the rate of unintended pregnancies in this age group. While all forms of birth control can generally be used by young people, long-acting reversible birth control such as implants, IUDs, or vaginal rings are more successful in reducing rates of teenage pregnancy. After the delivery of a child, a woman who is not exclusively breastfeeding may become pregnant again after as few as four to six weeks. Some methods of birth control can be started immediately following the birth, while others require a delay of up to six months. In women who are breastfeeding, progestin-only methods are preferred over combined oral birth control pills. In women who have reached menopause, it is recommended that birth control be continued for one year after the last menstrual period.
About 222 million women who want to avoid pregnancy in developing countries are not using a modern birth control method. Birth control use in developing countries has decreased the number of deaths during or around the time of pregnancy by 40% and could prevent 70% if the full demand for birth control were met. By lengthening the time between pregnancies, birth control can improve adult women's delivery outcomes and the survival of their children. In the developing world, women's earnings, assets, and weight, as well as their children's schooling and health, all improve with greater access to birth control. Birth control increases economic growth because of fewer dependent children, more women participating in the workforce, and/or less use of scarce resources.
Methods
| Method | Typical use | Perfect use |
| No birth control | 85% | 85% |
| Combination pill | 9% | 0.3% |
| Progestogen-only pill | 13% | 1.1% |
| Sterilization | 0.5% | 0.5% |
| Sterilization | 0.15% | 0.1% |
| Condom | 21% | 5% |
| Condom | 18% | 2% |
| Copper IUD | 0.8% | 0.6% |
| Hormonal IUD | 0.2% | 0.2% |
| Patch | 9% | 0.3% |
| Vaginal ring | 9% | 0.3% |
| MPA shot | 6% | 0.2% |
| Implant | 0.05% | 0.05% |
| Diaphragm and spermicide | 12% | 6% |
| Fertility awareness | 24% | 0.4–5% |
| Withdrawal | 22% | 4% |
| Lactational amenorrhea method | 0–7.5% | <2% |
Birth control methods include barrier methods, hormonal birth control, intrauterine devices, sterilization, and behavioral methods. They are used before or during sex, while emergency contraceptives are effective for up to five days after sex. Effectiveness is generally expressed as the percentage of women who become pregnant using a given method during the first year, and sometimes as a lifetime failure rate among methods with high effectiveness, such as tubal ligation.
Birth control methods fall into two main categories: male contraception and female contraception. Common male contraceptives are withdrawal, condoms, and vasectomy. Female contraception is more developed compared to male contraception, these include contraceptive pills, hormonal or non-hormonal IUD, patch, vaginal ring, diaphragm, shot, implant, fertility awareness, and tubal ligation.
The most effective methods are long-acting and do not require ongoing health care visits. Surgical sterilization, implantable hormones, and intrauterine devices all have first-year failure rates of less than 1%. Hormonal contraceptive pills, patches or vaginal rings, and the lactational amenorrhea method, if adhered to strictly, can also have first-year failure rates of less than 1%. With typical use, first-year failure rates are considerably higher, at 9%, due to inconsistent use. Other methods, such as condoms, diaphragms, and spermicides, have higher first-year failure rates even with perfect usage. The American Academy of Pediatrics recommends long acting reversible birth control as first line for young individuals.
While all methods of birth control have some potential adverse effects, the risk is less than that of pregnancy. After stopping or removing many methods of birth control, including oral contraceptives, IUDs, implants and injections, the rate of pregnancy during the subsequent year is the same as for those who used no birth control.
For individuals with specific health problems, certain forms of birth control may require further investigations. For women who are otherwise healthy, many methods of birth control should not require a medical exam—including birth control pills, injectable or implantable birth control, and condoms. For example, a pelvic exam, breast exam, or blood test before starting birth control pills does not appear to affect outcomes. In 2009, the World Health Organization published a detailed list of medical eligibility criteria for each type of birth control.
Hormonal
is available in several different forms, including oral pills, implants under the skin, injections, patches, IUDs and a vaginal ring. They are currently available only for women, although hormonal contraceptives for men have been and are being clinically tested. There are two types of oral birth control pills, the combined oral contraceptive pills and the progestogen-only pills. If either is taken during pregnancy, they do not increase the risk of miscarriage nor cause birth defects. Both types of birth control pills prevent fertilization mainly by inhibiting ovulation and thickening cervical mucus. They may also change the lining of the uterus and thus decrease implantation. Their effectiveness depends on the user's adherence to taking the pills.Combined hormonal contraceptives are associated with a slightly increased risk of venous and arterial blood clots. Venous clots, on average, increase from 2.8 to 9.8 per 10,000 women years which is still less than that associated with pregnancy. Due to this risk, they are not recommended in women over 35 years of age who continue to smoke. Due to the increased risk, they are included in decision tools such as the DASH score and PERC rule used to predict the risk of blood clots.
The effect on sexual drive is varied, with an increase or decrease in some but with no effect in most. Combined oral contraceptives reduce the risk of ovarian cancer and endometrial cancer and do not change the risk of breast cancer. They often reduce menstrual bleeding and painful menstruation cramps. The lower doses of estrogen released from the vaginal ring may reduce the risk of breast tenderness, nausea, and headache associated with higher dose estrogen products.
Progestin-only pills, injections, and intrauterine devices are not associated with an increased risk of blood clots and may be used by women with a history of blood clots in their veins. In those with a history of arterial blood clots, non-hormonal birth control or a progestin-only method other than the injectable version should be used. Progestin-only pills may improve menstrual symptoms and can be used by breastfeeding women as they do not affect milk production. Irregular bleeding may occur with progestin-only methods, with some users reporting no periods. The progestins drospirenone and desogestrel minimize the androgenic side effects but increase the risks of blood clots and are thus not the first line. The perfect use first-year failure rate of injectable progestin is 0.2%; the typical use first failure rate is 6%.
Barrier
s are devices that attempt to prevent pregnancy by physically preventing sperm from entering the uterus. They include male condoms, female condoms, cervical caps, diaphragms, and contraceptive sponges with spermicide.Globally, condoms are the most common method of birth control. Male condoms are put on a man's erect penis and physically block ejaculated sperm from entering the body of a sexual partner. Modern condoms are most often made from latex, but some are made from other materials such as polyurethane, or lamb's intestine. Female condoms are also available, most often made of nitrile, latex or polyurethane. Male condoms have the advantage of being inexpensive, easy to use, and have few adverse effects. Making condoms available to teenagers does not appear to affect the age of onset of sexual activity or its frequency. In Japan, about 80% of couples who are using birth control use condoms, while in Germany this number is about 25%, and in the United States it is 18%.
Male condoms and the diaphragm with spermicide have typical use first-year failure rates of 18% and 12%, respectively. With perfect use, condoms are more effective with a 2% first-year failure rate versus a 6% first-year rate with the diaphragm. Condoms have the additional benefit of helping to prevent the spread of some sexually transmitted infections, such as HIV/AIDS; however, condoms made from animal intestines do not.
Contraceptive sponges combine a barrier with a spermicide. Like diaphragms, they are inserted vaginally before intercourse and must be placed over the cervix to be effective. Typical failure rates during the first year depend on whether or not a woman has previously given birth, being 24% in those who have and 12% in those who have not. The sponge can be inserted up to 24 hours before intercourse and must be left in place for at least six hours afterward. Allergic reactions and more severe adverse effects such as toxic shock syndrome have been reported.