County Health Rankings Model

Sexual Activity

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Use County Health Rankings’ model of health to explore the measures that influence how long and how well we live.

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Sexually transmitted infections (STIs) and unplanned pregnancies, often the result of risky sexual behavior, have lasting effects on health and well-being, especially for adolescents.

Why Is Sexual Activity Important to Health?

High risk sexual practices such as unsafe sex and higher numbers of lifetime sexual partners can lead to sexually transmitted infections (STIs) and unplanned pregnancies, which can affect immediate and long-term health as well as the economic and social well-being of individuals, families, and communities.

Recent data show increasing rates of syphilis, gonorrhea, and chlamydia infections. Young people, gay men, and bisexual men are at higher risk for STIs, which can have severe reproductive health complications, particularly for young women [1]. Human papillomavirus (HPV) causes almost all cervical and anal cancers, as well as the majority of vaginal, vulvar, penile and oropharyngeal cancers [2]. Some STIs, such as HIV and herpes, cannot be cured.

There are approximately 3 million unintended pregnancies in the US each year. Rates are highest among poor, minority, young, and cohabiting women. Unintended pregnancy is associated with delayed prenatal care [3].

The teen pregnancy rate is falling, but as of 2016, there were still over 200,000 teen pregnancies annually [4]. Pregnant teens are less likely than older women to receive recommended prenatal care [5], and more likely to have pre-term or low birthweight babies [6]. Teen mothers are often at increased risk for STIs and repeat pregnancies [7], are less likely than their peers to complete high school, and more likely to live below the poverty level and rely on public assistance [8]. 

Risky sexual behaviors can have high economic costs for communities and individuals. STIs cost the US health care system almost $16 billion every year [1] and, in 2010, the costs of teen childbearing were estimated at over $9 billion [4]. Communities, schools, and families can work together to adopt and implement policies and programs that reduce STIs and unplanned pregnancies, to the benefit of all.


[1] Centers for Disease Control and Prevention. 2017 Sexually Transmitted Disease Surveillance. Reported STDs in the United States, 2017. September 2018. Accessed March 14, 2019.
[2] National Cancer Institute. HPV and Cancer. March 1, 2019. Accessed March 14, 2019.
[3] Guttmacher Institute. Unintended pregnancy in the United States. New York: Guttmacher Institute; 2016.  
[4] National Campaign to Prevent Teen and Unplanned Pregnancy. National & state data. 2017. 
[5] Lee SH, Lee SM, Lim NG, et al. Differences in pregnancy outcomes, prenatal care utilization, and maternal complications between teenagers and adult women in Korea: A nationwide epidemiological study. Medicine. 2016.
[6] Chandra PC, Schiavello HJ, Ravi B, Weinstein AG, Hook FB. Pregnancy outcomes in urban teenagers. International Journal of Gynaecology & Obstetrics. 2002; 79:117-122.
[7] Meade CS, Ickovics JR. Systematic review of sexual risk among pregnant and mothering teens in the USA: Pregnancy as an opportunity for integrated prevention of STD and repeat pregnancy. Social Science & Medicine. 2005; 60:661-678.
[8] National Campaign to Prevent Teen Pregnancy. Why it Matters: Teen childbearing, education, and economic well-being. July 2012.


Our Rankings show how healthy a community is as well as indicators for future health. This provides a starting point for action on improving health for all. Dig deeper into the measures below to learn more about our approaches to measuring health.