Sexual Activity

Early sexual activity is associated with emotional93 and physical health risks. Youth who engage in sexual activity are at risk of contracting sexually transmitted infections (STIs) and becoming pregnant. STIs, including HIV, can infect a person for a lifetime and have consequences, including disability and early death. Delaying sexual initiation is associated with a decrease in the number of lifetime sexual partners,94 and having fewer lifetime partners is associated with a decrease in the rate of STIs.95, 96 In addition, teen pregnancy is associated with a number of negative risk factors, for not only the mother but also for her child (see FAM6).

Indicator BEH4.A: Percentage of high school students who reported ever having had sexual intercourse by grade, selected years 1991–2019
Indicator BEH4.A: Percentage of high school students who reported ever having had sexual intercourse by grade, selected years 1991–2019

NOTE: Students were asked, "Have you ever had sexual intercourse?" Data are collected biennially.

SOURCE: Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Youth Risk Behavior Surveillance System.

Indicator BEH4.B: Among students who had sexual intercourse in the past 3 months, the percentage who reported birth control pill use before or condom use during their last sexual intercourse, selected years 1991–2019
Indicator BEH4.B: Among students who had sexual intercourse in the past 3 months, the percentage who reported birth control pill use before or condom use during their last sexual intercourse, selected years 1991–2019

NOTE: Students were asked, "The last time you had sexual intercourse, did you or your partner use a condom?" and "The last time you had sexual intercourse, what one method did you or your partner use to prevent pregnancy?" "Birth control pills" was one option. Data are collected biennially.

SOURCE: Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Youth Risk Behavior Surveillance System.

  • The percentage of students reporting ever having had sexual intercourse declined from 54% in 1991 to 46%in 2001 and was relatively stable through 2013 (47%) before decreasing to 38% in 2019.97
  • Between 1991 and 2019, the percentage of students reporting ever having had sexual intercourse declined among all four grades: 9th grade (39% to 19%), 10th grade (48% to 34%), 11th grade (62% to 47%), and 12th grade (67% to 57%).
  • In 2019, of students who had sexual intercourse in the past 3 months, about 23% reported that they or their partner had used birth control pills before their last sexual intercourse, and 54% reported condom use. Condom use increased between 1991 (46%) and 2005 (63%) and then decreased between 2005 and 2019.


















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93 Meier, A. M. (2007). Adolescent first sex and subsequent mental health. American Journal of Sociology, 112(6), 1811–1847.

94 Chandra, A., Martinez, G. M., Mosher, W. D., Abma, J. C., & Jones, J. (2005). Fertility, family planning, and reproductive health of U.S. women: Data from the 2002 National Survey of Family Growth. Vital and Health Statistics, 23(25), 1–160.

95 Dunne, E. F., Unger, E. R., Sternberg, M., McQuillan, G., Swan, D. C., Patel, S. S., & Markowitz, L. E. (2007). Prevalence of HPV infection among females in the United States. Journal of the American Medical Association, 297(8), 813–819.

96 Gottlieb, S. L., Pope, V., Sternberg, M. R., McQuillan, G. M., Beltrami, J. F., Berman, S. M., & Markowitz, L. E. (2008). Prevalence of syphilis seroreactivity in the United States: Data from the National Health and Nutrition Examination Surveys (NHANES) 2001–2004. Sexually Transmitted Diseases, 35(5), 507–511.

97 Beginning in 2011, t-tests were used for this report to test for significant differences between groups. Comparisons of confidence intervals were used to test for significant differences prior to 2011.