Among sexually active 15- to 19-year-olds, 83% of females and 91% of males reported using at least one method of birth control during last intercourse

Among sexually active 15- to 19-year-olds, 83% of females and 91% of males reported using at least one method of birth control during last intercourse. Thus, sexually active adolescent women wishing to avoid pregnancy are less likely than those of other ages to use contraceptives (18% of 15- to 19-year-olds used no contraceptives, versus 10.7% average for women ages 15 to 44), according to an analysis of periodic survey data from the National Center for Health Statistics.

Among adolescents, the most common methods of contraception are birth control pills (used by 43.5% of 15- to 19-year-old women at risk for unintended pregnancy) and condoms (used by 22% of adolescent women). In 2007, 61.5% of high school students reported using a condom the last time they had sexual intercourse, up from 46% in 1991. Adolescent women are more likely to use Depo Provera (11% of teens versus 4.8% for women ages 15 to 44) but less likely to use IUDs (0.2% versus 1.9% overall), which require little user action and are thus among the most effective in typical use.

While 90% of teens surveyed in a poll commissioned by NBC News and People magazine knew they could get an STD from having sexual intercourse, only 67% said that they use protection every time they have sex.Boys who have received sex education are three times more likely to use contraception than their peers who have not, but for girls there is no difference. Before the 1980s, 57% of 15- and 16-year-old girls did not use contraception the first time they had intercourse. By 2007, that number fell to 25%.

Girls who stop using contraception after the first time they have intercourse have been found more likely than those who continue to use it to be less able and willing to plan for sexual intercourse, less apt to believe that pregnancy was likely to occur and less apt to want to remain non-pregnant. They were also more likely to be older and to have been sexually active for at least 6 months. Girls who stopped using contraception were also less likely to have career goals and had more positive expectations themselves about the effects of childbearing on their lives.

One simulation projected that increasing contraceptive availability among teenagers reduces teen pregnancies in the short run, but may result in more teen pregnancies in the long run. The researchers found "that even well intended contraception policies can be self-defeating." This study also found that decreasing access to contraception leads to lower rates of sexual activity among teenagers and thus will lower the teen pregnancy rate in the long run. However, another study outlined the dangers of new laws being enacted that limit adolescents' access to contraceptives, including condoms.