The County Health Rankings model of population health
Explore guides and tools for improving health
Key findings from the last three years of County Health Rankings and other national reports.
Project updates, commentaries, events and news about health across the nation from the County Health Rankings & Roadmaps team.
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.
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 . Human papillomavirus (HPV) causes almost all cervical and anal cancers, as well as some vaginal, vulvar, penile and oropharyngeal cancers . 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 .
The teen pregnancy rate is falling, but as of 2010, there were still over 600,000 teen pregnancies annually . Pregnant teens are less likely than older women to receive recommended prenatal care , and more likely to have pre-term or low birthweight babies . Teen mothers are often at increased risk for STIs and repeat pregnancies , are less likely than their peers to complete high school, and more likely to live below the poverty level and rely on public assistance .
Risky sexual behaviors can have high economic costs for communities and individuals. STIs cost the US health care system almost $16 billion every year  and, in 2010, the costs of teen childbearing were estimated at over $9 billion . 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.
The County Health Rankings use two measures in the sexual activity focus area:
By measuring teen births and chlamydia incidence rates, the County Health Rankings provide communities with a sense of the level of risky sexual behavior in their county compared to other counties in their state.
For more information about measuring Sexual Activity click here.
 National Center for HIV/AIDS, Viral Hepatitis, STD and TP. Reported STDs in the United States: 2012 National data for chlamydia, gonorrhea, and syphilis. Atlanta: Centers for Disease Control and Prevention (CDC); 2014.
 National Cancer Institute. HPV and Cancer. Last reviewed March 15, 2012. Accessed March 3, 2014.
 Guttmacher Institute. Unintended pregnancy in the United States. New York: Guttmacher Institute; 2016.
 National Campaign to Prevent Teen and Unplanned Pregnancy. National & state data. March 2015.
 Scholl TO, Hediger ML, Belsky DH. Prenatal care and maternal health during adolescent pregnancy - A review and meta-analysis. J Adolesc Health. 1994;15:444-456.
 Chandra PC, Schiavello HJ, Ravi B, Weinstein AG, Hook FB. Pregnancy outcomes in urban teenagers. Int J Gynaecol Obstet. 2002;79:117-122.
 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. Soc Sci Med. 2005;60:661-678.
 National Campaign to Prevent Teen Pregnancy. Why it Matters: Teen childbearing, education, and economic well-being. July 2012.
Explore the Rankings Data