Risk Factors for Early Sexual Intercourse in Adolescence: A Systematic Review of Cohort Studies.

This systematic review provides a comprehensive assessment of risk factors related to early sexual intercourse (ESI) among adolescents. We used PRISMA guidelines to identify eligible cohort studies published between January 1999 and December 2020. We searched on three databases: PubMed, Embase and LILACS. Studies were screened for quality and eligibility. Of 2787 identified studies, seven met our inclusion criteria. The studies examined a range of factors, which were organized into four dimensions - individual, family, social and environmental, and sociodemographic. Risk factors with strong associations for ESI were: adolescent and parental substance use, aggression and conduct disorders, family attachment, school achievement, family living situation, and maternal education. Three studies were birth cohorts. This review demonstrates the important roles of substance use, family attachment and academic factors in shaping adolescents' sexual behavior. A strength of this review is its focus on longitudinal studies, enabling exploration of exposures collected before initiation of sexual intercourse.