The debate over teenage pregnancy and STDs has spurred some research into the effectiveness of different approaches to sex education. In a meta-analysis, DiCenso et al. have compared comprehensive sex education programs with abstinence-only programs. Their review of several studies shows that abstinence-only programs did not reduce the likelihood of pregnancy of women who participated in the programs, but rather increased it. Four abstinence programs and one school program were associated with a pooled increase of 54% in the partners of men and 46% in women (confidence interval 95% 0.95 to 2.25 and 0.98 to 2.26 respectively). The researchers conclude:
There is some evidence that prevention programs may need to begin much earlier than they do. In a recent systematic review of eight trials of day care for disadvantaged children under 5 years of age, long term follow up showed lower pregnancy rates among adolescents. We need to investigate the social determinants of unintended pregnancy in adolescents through large longitudinal studies beginning early in life and use the results of the multivariate analyses to guide the design of prevention interventions. We should carefully examine countries with low pregnancy rates among adolescents. For example, the Netherlands has one of the lowest rates in the world (8.1 per 1000 young women aged 15 to 19 years), and Ketting & Visser have published an analysis of associated factors. In contrast, the rates are: 93.0 per 1000 in the United States
We should examine effective programs designed to prevent other high risk behaviors in adolescents. For example, Botvin et al. found that school based programs to prevent drug abuse during junior high school (ages 12–15 years) resulted in important and durable reductions in use of tobacco, alcohol, and cannabis if they taught a combination of social resistance skills and general life skills, were properly implemented, and included at least two years of booster sessions.
Few sexual health interventions are designed with input from adolescents. Adolescents have suggested that sex education should be more positive with less emphasis on anatomy and scare tactics; it should focus on negotiation skills in sexual relationships and communication; and details of sexual health clinics should be advertised in areas that adolescents frequent (for example, school toilets, shopping centres)."
Also, a U.S. review, "Emerging Answers", by the National Campaign To Prevent Teenage Pregnancy examined 250 studies of sex education programs. The conclusion of this review was that "the overwhelming weight of evidence shows that sex education that discusses contraception does not increase sexual activity". The National Campaign published a follow up study in 2007 titled, "Emerging Answers 2007", reviewing fewer studies but confirming the original findings. The 2007 study found that, "No comprehensive program hastened the initiation of sex or increased the frequency of sex, results that many people fear." Further, the report showed "Comprehensive programs worked for both genders, for all major ethnic groups, for sexually inexperienced and experienced teens, in different settings, and in different communities."