Effectiveness of School-Based Teen Pregnancy Prevention Programs in the USA: a Systematic Review and Meta-Analysis

School-based programs have been a mainstay of youth pregnancy prevention efforts in the USA. We conducted a systematic review and meta-analysis to assess their effectiveness. Eligible studies evaluated the effect on pregnancy rates of programs delivered in elementary, middle, or high schools in the USA and Canada, published between January 1985 and September 2016. The primary outcome was pregnancy; secondary outcomes were delay in sexual initiation, condom use, and oral contraception use. Randomized controlled trials (RCTs) and non-RCTs with comparator groups were eligible. We developed a comprehensive search strategy, applied to major bibliographic databases, article bibliographies, gray literature, and contact with authors. We calculated risk ratios (RR) with 95% confidence intervals (CI) for each outcome and pooled data in random effects meta-analysis. We used Grading of Recommendations Assessment, Development and Evaluation (GRADE) to assess evidence quality. Ten RCTs and 11 non-RCTs conducted from 1984 to 2016 yielded 30 unique pooled comparisons for pregnancy, of which 24 were not statistically significant. Six showed statistically significant changes in pregnancy rates: two with increased risk (RR 1.30, 95% CI 1.02-1.65; and RR 1.39, 95% CI 1.10-1.75) and four with decreased risk ranging from RR 0.56, 95% CI 0.41-0.77, to RR 0.75, 95% CI 0.58-0.96. All studies were at high risk of bias, and the quality of evidence was low or very low. Identified evidence indicated no consistent difference in rates of pregnancies between intervention recipients and controls.