RESUMEN
Adolescent pregnancy is a major public health issue with profound implications for health and socioeconomic factors. The use of long-acting reversible contraception (LARC) could be an interesting strategy to reduce the unintended pregnancy rate. However, the cost of LARC is still a barrier to widespread adoption. This study aimed to analyze the effectiveness and economic impact of LARC compared with non-LARC methods in preventing unintended pregnancy among adolescent girls. This systematic review was registered in PROSPERO (CRD42023387735) and conducted following the PRISMA guidelines. We included articles covering adolescents aged 10-19 years without language restrictions that evaluated the use of LARC compared with non-LARC in terms of effectiveness and the public health costs of unintended pregnancy. The search for articles included the databases MEDLINE/PubMed, Cochrane Library, Embase, and Lilacs, using the entry terms "Adolescent" and "Long-Acting Reversible Contraception." We evaluated the risk of bias and the certainty of the evidence for each outcome of interest. The search retrieved a total of 1,169 articles and, after the title and abstract, we identified 40 articles for full-text analysis. Out of the 40 studies evaluated, 4 articles met the eligibility criteria for cost evaluation, and 1 met the eligibility criteria for effectiveness as an outcome. In conclusion, LARC emerges as the most effective and cost-effective contraceptive method. The cost of utilizing LARC, especially the copper IUD, is significantly lower than the costs attributable to unintended pregnancies in adolescence.