Role of Alcohol and Drugs in Premarital Sex, STIs, & Pregnancy

Premarital sex not only places young persons at immediate risk for pregnancy but also increases their risk for all STIs, including HIV. More than 700,000 teenagers become pregnant each year.[1] One in 3 (34%) females become pregnant at least once before age 20,[2] and 11% of pregnant 15- to 17-year-olds have been pregnant at least once before.[3] 20% of female teens are sexually active before the age of 15. 14% of these will become pregnant during their teen years.[3]

According to the Youth Risk Behavior Survey (YRBS), the overall proportion of both sexually experienced teens (54.1% – 46.8%) and currently sexually active teens (37.5% – 33.9%) decreased from 1991 through 2005. In contrast, the prevalence of alcohol or drug use before last sex increased slightly (21.6% – 23.3%) over the same time frame.[4]

The consequences of alcohol and drug use are especially serious for teens. Substance abuse affects a person’s ability to make judgments about sexual behavior, thus increasing the risk for sexually transmitted infections, sexual assault, and pregnancy. According to a survey by the Kaiser Family Foundation, a quarter of teens report having gone further than they intended in a sexual situation while under the influence of alcohol or drugs.[5] And nearly 1 in 5 sexually active teens said they were using drugs or alcohol when they lost their virginity.[6]

About one-fifth of teens who drink or use drugs while having sex have later worried about STIs or pregnancy.[5] Early sexual debut increases the likelihood of multiple partners and of adverse outcomes such as STIs and nonmarital teen pregnancy.[3] Pregnant teens are at risk of medical complications such as toxemia, hypertension, anemia, and premature delivery. And unmarried teen mothers are less emotionally and physically capable of having a healthy baby.

Given that alcohol and drug use can seriously impair judgment, and that teens are particularly susceptible to these effects, parents and other mentoring adults should
– clearly communicate their expectations regarding substance use
– clearly communicate their expectations regarding sexual activity
– monitor where teens go, who they are with, and what they are doing

1. The Guttmacher Institute. (2006) U.S. Teenage Pregnancy Statistics National and State Trends and Trends by Race and Ethnicity. New York: The Guttmacher Institute.
2. National Campaign to Prevent Teen Pregnancy. How is the 3 in 10 statistic calculated? October 2006. Available online at :
3. National Campaign to Prevent Teen Pregnancy. 14 and Younger: The Sexual Behavior of Young Adolescents., May 2003. Available online at:
4. CDC. YRBS. National Youth Risk Behavior Survey: 1991-2005. Trends in Prevalence of Sexual Behaviors. Available online at:
5. Kaiser Family Foundation. National Survey of Adolescents and Young Adults: Sexual Health Knowledge, Attitudes and Behaviors. May 2003.
6. Kaiser Family Foundation. Virginity and the First Time. October 2003. Available online at:

Reviewed: August 2007