Prioritizing adolescent health is a public health priority to achieve the sustainable development goals, including reducing the risk of unsafe sex. Data on unsafe sex have remained scarce among adolescents in low-and middle-income countries (LMICs). To estimate the prevalence of unsafe sex in LMICs, we conducted secondary data analysis on the Global School-based Student Health Surveys among 244,863 students aged 13–17 years from 68 countries across five World Health Organization regions. The overall prevalence of ever had sex was 16.2%. The highest to lowest regional prevalence estimation of ever had sex was 30.5% (28.9–32.1) in the Americas, 28.6% (26.8–30.4) in Africa, 10.9% (9.2–12.6) in the Eastern Mediterranean, 9.6% (8.8–10.5) in South-East Asia, and 8.0% (6.8–9.1) in the Western Pacific. The highest prevalence of sexual intercourse before age 14 and practicing sexual intercourse without condom use were 36.5% (34.5–38.5) and 32.2% (30.1–34.3) in Africa, respectively. Findings suggest that current interventions are inadequate in promoting the uptake of safe sexual behaviors and an urgent intervention is needed.

优先考虑青少年健康是实现可持续发展目标（包括降低不安全性行为风险）的公共卫生优先事项。低收入和中等收入国家 (LMIC) 青少年中有关不安全性行为的数据仍然很少。为了估计中低收入国家不安全性行为的发生率，我们对来自世界卫生组织五个区域的 68 个国家的 244,863 名 13-17 岁学生进行的全球学校学生健康调查进行了二次数据分析。曾经有过性行为的总体患病率为16.2%。曾经有过性行为的区域患病率从最高到最低估计分别为美洲 30.5% (28.9–32.1)、非洲 28.6% (26.8–30.4)、东地中海 10.9% (9.2–12.6)、9.6% (8.8–东南亚为 10.5%，西太平洋为 8.0% (6.8–9.1)。在非洲，14 岁之前发生性行为和不使用安全套发生性行为的最高比例分别为 36.5%（34.5-38.5）和 32.2%（30.1-34.3）。研究结果表明，目前的干预措施不足以促进安全性行为的形成，需要紧急干预。