School, community, family, clinic, and technology-based approaches to adolescent pregnancy prevention: a comprehensive systematic review

Adolescent pregnancy remains a global public health issue associated with adverse maternal and neonatal outcomes, educational disruption, and long-term socioeconomic consequences. This systematic review synthesised evidence on school, community, family, clinic, and technology-based interventions for adolescent pregnancy. A comprehensive literature search was conducted in Embase, ProQuest, Scopus, and PubMed to identify relevant articles published between 2018 and 2023 The screened articles were full-text, and the selected articles were open access. The search strategy combined MeSH terms and keywords using the Boolean operators Reviews and Meta-Analyses guidelines, 1352 records were identified, and 25 studies (randomised controlled trials [RCTs], mixed-methods, quasi-experimental) were included. Study quality and risk of bias were assessed using structured appraisal tools: the Joanna Briggs Institute Guidelines Tools for RCTs and quasi-experimental studies, and the Mixed Methods Appraisal Tools for mixed-methods studies. The findings were analysed through a design-stratified narrative synthesis to account for methodological heterogeneity. A meta-analysis was not conducted because the included studies were methodologically and clinically heterogeneous, thereby limiting the validity of pooling effect sizes. School- and technology-based interventions improved sexual health knowledge and attitudes but showed limited behavioural change. Community programs demonstrated moderate improvements in contraceptive use and delayed sexual initiation at 6–12 months. Clinic-based models increased communication and service utilisation but rarely measured pregnancy incidence. Only intensive family-based interventions with structured reinforcement reduced pregnancy rates at ≥12 months. Knowledge improvement does not guarantee a reduction in pregnancy. Sustained impact depends on intervention intensity, reinforcement, and long-term follow-up, supporting integrated multicomponent strategies with standardised pregnancy indicators.