Contraceptive use and associated factors among female adolescents in Northeast Brazil: a school-based cross-sectional study

<h2>Abstract</h2><h3>Objective</h3> This study aimed to characterize the sociodemographic profile, sexual and reproductive health (SRH) indicators, and factors associated with contraceptive use among female adolescents in public schools from Northeast Brazil. <h3>Methods</h3> A school-based cross-sectional study was conducted in two public secondary schools in São Luís, Brazil. Participants included 627 female adolescents, aged 15–19 years. Data were collected using a pre-tested, structured, anonymous questionnaire covering sociodemographic characteristics, SRH history, contraceptive practices, and STI-related variables. Modified Poisson regression was used to identify factors associated with current contraceptive use among sexually active adolescents. <h3>Results</h3> Overall, 67.7% of participants reported being sexually active, with 30.0% initiating sexual activity at ≤ 14 years. In addition, 36.5% had never attended a SRH consultation. Among sexually active adolescents, 52.7% reported current contraceptive use, predominantly male condoms (50.7%) and oral contraceptives (48.8%). Factors independently associated with higher contraceptive use were older age (17–19 years, aPR: 1.32, 95% CI: 1.05–1.66), SRH consultation (aPR: 2.01, 95% CI: 1.52–2.66), and pregnancy prevention as primary motivation (aPR: 1.45, 95% CI: 1.11–1.89). Lower socioeconomic class (aPR: 0.77, 95% CI: 0.61–0.98) and STI history (aPR: 0.79; 95% CI: 0.63–0.99) were associated with lower use. <h3>Conclusions</h3> The study findings reveal critical gaps in SRH care among adolescent girls in Northeast Brazil. SRH consultations were found to be a predictor of contraceptive use, highlighting the transformative potential of clinical contact, particularly in primary healthcare settings. The inverse association between STI history and contraceptive use challenges simplistic behavioral models and suggests deeper vulnerabilities.