<unk> , also known as contraception, anticonception, and fertility<unk> , is a method or device used to prevent pregnancy.<unk>  has been used since ancient times, but effective and safe methods of<unk>  only became available in the 20th century. Planning, making available, and using<unk>  is called family planning. Some cultures limit or discourage access to<unk>  because they consider it to be morally, religiously, or politically undesirable. The term<unk>  is a bit of a misnomer since abortion is not regularly considered under the term. The World Health Organization and United States Centers for Disease<unk>  and Prevention provide guidance on the safety of<unk>  methods among women with specific medical conditions. The most effective methods of<unk>  are sterilization by means of vasectomy in males and tubal ligation in females, intrauterine devices (IUDs), and implantable<unk> . This is followed by a number of hormone-based methods including oral pills, patches, vaginal rings, and injections. Less effective methods include physical barriers such as condoms, diaphragms and<unk>  sponges 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 male or female condoms, can also help prevent sexually transmitted infections. Other methods of<unk>  do not protect against sexually transmitted diseases. Emergency<unk>  can prevent pregnancy if taken within 72 to 120 hours after unprotected sex. Some argue not having sex is also a form of<unk> , but abstinence-only sex education may increase teenage pregnancies if offered without<unk>  education, due to non-compliance. In teenagers, pregnancies are at greater risk of poor outcomes. Comprehensive sex education and access to<unk>  decreases the rate of unwanted pregnancies in this age group. While all forms of<unk>  can generally be used by young people, long-acting reversible<unk>  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<unk>  can be started immediately following the<unk> , while others require a delay of up to six months. In women who are breastfeeding, progestin-only methods are preferred over combined oral<unk>  pills. In women who have reached menopause, it is recommended that<unk>  be continued for one year after the last period. About 222 million women who want to avoid pregnancy in developing countries are not using a modern<unk>  method.<unk>  use in developing countries has decreased the number of deaths during or around the time of pregnancy by 40% (about 270,000 deaths prevented in 2008) and could prevent 70% if the full demand for<unk>  were met. By lengthening the time between pregnancies,<unk>  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<unk> .<unk>  increases economic growth because of fewer dependent children, more women participating in the workforce, and less use of scarce resources. Video explaining how to prevent unwanted pregnancy
Birth control
Prenatal care
Well-woman examination
Prenatal and perinatal psychology
Pregnancy test
Newborn screening
Post-abortion care
Pregnancy options counseling