Trends and socioeconomic differences in early sexual debut before marriage among teenage and young girls in sub-Saharan Africa, 2000-2023

Introduction: In sub-Saharan Africa, early sexual debut (ESD) exposes adolescent girls to increased risks of unwanted pregnancy, sexually transmitted infections and dropping out of school. This study analyses trends in ESD and socioeconomic differences according to place of residence. Methods: The data come from three cycles of Demographic and Health Surveys conducted between 2000 and 2023 in 18 countries, covering 80,432 sexually active adolescent girls and young women. The analyses combine cross-tabulations, comparison of proportions tests and binary logistic regressions, at the 5% threshold, using STATA 17. Results: The results indicate that the prevalence of ESD gradually decreased from 18.7% during the first half of the Millennium Development Goals (MDGs, 2000-2008) to 18.2% during the second half (2009-2015), and then to 15.5% during the first half of the Sustainable Development Goals (SDGs, 2016-2023). The decline is significant, reaching 14.8% between the end of the MDGs and the start of the SDGs (p=0.000), and 17.1% between the start of the MDGs and the start of the SDGs (p=0.000). Adolescent girls are at least twice as likely to be at risk of ESD as older girls, with greater vulnerability in rural areas (Ajusted Odds Ratio: aOR=3.04; p<0.001) than in urban areas (aOR=2.88; p<0.001). Socio-economic disparities are also notable. Adolescent girls and young women from poor or very poor households are 1.48 times more exposed to ESD, especially in urban areas (aOR=1.98; p<0.000) compared with 1.17 in rural areas (p<0.05). Conversely, education appears to be a protective factor regardless of place of residence. Conclusion: These results underline the urgent need to strengthen sexual and reproductive health awareness strategies, particularly targeting rural areas and the least educated young girls. Public policies should promote access to education and information to delay the onset of ESD and reduce its impact on the health and schooling of adolescent girls in sub-Saharan Africa.