Prevalence of high-risk sexual behavior among Iranian young people: A systematic review and meta-analysis

•Pre/extramarital sexual relations are illegal and taboo in Iran.•These relations are relatively common among Iranian youth.•The pre/extramarital sex was approximately twice higher in young males than in females.•Millions of Iranian youth are exposed to unprotected sexual relationships and their potential consequences. Sex out of marriage is considered to be illegal, non-religious, immoral, and taboo in Iran. Risky sexual behaviors, such as condomless sex, multiple sexual partners, starting sex at an early age, adversely affect young people's health and expose them to sexually transmitted infections and unwanted pregnancy to females. These behaviors could lead to deleterious health, social and economic consequences. We conducted a systematic review to estimate the prevalence of extra/premarital sex and high-risk sexual behaviors among Iranian young people. We systematically searched seven databases to identify relevant studies up to 22nd of December 2019 and we found 28 eligible studies implemented in Iran. The pooled prevalence of life-time extra/premarital sex was estimated at 24% (95% CI: 17–30) overall, 33% (95% CI: 25–40) in male and 14% (95% CI: 8–19) in female. Moreover, the prevalence of high-risk sexual behaviors such as having condomless sex (12.8% to 89.6%), multi-sex partners (7.7% to 62.9%), sex in return for payment (1.3% to 7.0%), and starting sexual activity at under 15 years (24.0% to 60.5%) was varied between studies. These findings suggested relatively high extra/premarital sex and unsafe sex behaviors among young people and the need for targeted, appropriate sex education programs.