Cochrane for Clinicians

Putting Evidence into Practice

Preventing Unintended Adolescent Pregnancy


Am Fam Physician. 2017 Apr 1;95(7):422-423.

Author disclosure: No relevant financial affiliations.

Clinical Question

Which interventions are effective in preventing unintended adolescent pregnancy and its antecedent risk behaviors?

Evidence-Based Answer

Among adolescents, educational interventions increase reported condom use at most recent intercourse (number needed to treat [NNT] = 21; Strength of Recommendation [SOR]: B, based on inconsistent or limited-quality patient-oriented evidence), whereas contraceptive-promoting interventions increase use of hormonal contraception (NNT = 5; SOR: A, based on consistent, good-quality patient-oriented evidence). Combining these interventions lowers the risk of unintended pregnancy compared with existing conventional population-wide activities alone1 (NNT = 25; SOR: B, based on inconsistent or limited-quality patient-oriented evidence).

Practice Pointers

Unintended adolescent pregnancy is associated with adverse physical and psychological outcomes for mother and child, lower lifelong socioeconomic and educational achievement, and higher medical costs.2 Births among adolescents have been decreasing over time in most countries, including the United States, primarily because of lower rates of sexual activity and higher rates of contraception use.24 However, the rate of unintended adolescent pregnancy in the United States is higher than in many other industrialized countries and disproportionately affects minority and impoverished youth.3,4

This Cochrane review included 53 trials with 105,368 adolescents across community, home, school, and clinic settings in varied cultural and economic contexts.1 Unintended pregnancy was significantly reduced over medium- and long-term follow-up periods among participants who were randomized to receive a combination of educational and contraceptive-promoting interventions compared with those who received standard sex education, general counseling, or no intervention (relative risk [RR] = 0.66; 95% confidence interval [CI], 0.5 to 0.87; NNT = 25; 95% CI, 17 to 67; n = 1,905). However, among those receiving multiple interventions, the evidence was inconclusive regarding rates of sexually transmitted infections, use of birth control, and abortion.

In cluster randomized controlled trials, the authors found that participants who had received educational interventions (e.g., health education by the parent or peers) were more likely to have used condoms at their most recent intercourse than those who had not received that education (RR = 1.18; 95% CI, 1.06 to 1.32; NNT = 21; 95% CI, 12 to 63; n = 1,431). Education alone did not delay the initiation of sexual intercourse compared with control interventions, and rates of unintended pregnancy were not reported in those studies. Furthermore, individual randomized controlled trials demonstrated that adolescents who were encouraged to use contraception were more likely to use hormonal contraception than those who did not receive that intervention (RR = 2.22; 95% CI, 1.07 to 4.62; NNT = 5; 95% CI, 2 to 91; n = 3,091). Within the analyses, variability among studies and lack of direct comparisons precluded identification of the most effective intervention within each strategy.

The Centers for Disease Control and Prevention recommends that clinicians broadly and confidentially inquire about adolescents' reproductive health care needs and offer services at every encounter.5 This Cochrane review provides additional evidence that education and concurrent information about contraception can decrease the risk of unintended adolescent pregnancy.1

The practice recommendations in this activity are available at

editor's note: The numbers needed to treat reported in this Cochrane for Clinicians were calculated by the AFP medical editors based on raw data provided in the original Cochrane review.

The views expressed in this article are those of the authors and do not reflect the official policy or position of Fort Belvoir Community Hospital, the Departments of the Air Force or Navy or their respective Medical Departments, the Department of Defense, or the U.S. government.

Author disclosure: No relevant financial affiliations.


show all references

1. Oringanje C, Meremikwu MM, Eko H, Esu E, Meremikwu A, Ehiri JE. Interventions for preventing unintended pregnancies among adolescents. Cochrane Database Syst Rev. 2016;(2):CD005215....

2. Dalby J, Hayon R, Carlson J. Adolescent pregnancy and contraception. Prim Care. 2014;41(3):607–629.

3. Finer LB, Zolna MR. Declines in unintended pregnancy in the United States, 2008–2011. N Engl J Med. 2016;374(9):843–852.

4. The World Bank. Adolescent fertility rate (births per 1,000 women ages 15–19). United NationsPopulation Division, World Population Prospects. Accessed May 20, 2016.

5. Gavin L, Moskosky S, Carter M, et al. Providing quality family planning services: recommendations of CDC and the U.S. Office of Population Affairs. MMWR Recomm Rep. 2014;63(RR-04):1–54.

These are summaries of reviews from the Cochrane Library.

This series is coordinated by Corey D. Fogleman, MD, Assistant Medical Editor.

A collection of Cochrane for Clinicians published in AFP is available at



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