Changing patterns of education, marriage and fertility in Chinese adolescents: a systematic synthesis of national and subnational population data from 1990 to 2020.

Background: Secondary education, and early marriage and childbirth are major determinants of health and wellbeing. We aimed to describe the long-term trends and inequalities of these three indicators in Chinese adolescents over three decades of dramatic social and economic change. Methods: Using data from Chinese population censuses and 1% population sample surveys from 1990 to 2020 (the most recent survey), we calculated the senior secondary school participation rate in 20-24-year-olds, the ever-married rate in 15-19-year-olds, and the age-specific fertility rate in 15-19 year-old females, by urban-rural location and province. Findings: In urban areas, the secondary school participation rate substantially increased, from 34.7% in 1990 to 82.4% in 2020 for females and from 38.7% to 77.0% for males. The participation rate in rural areas also greatly increased, from 5.0% in 1990 to 55.7% in 2020 for females and from 9.1% to 51.0% for males, but remained markedly lower than in urban areas at all time points. The ever-married rate decreased dramatically from 1990 to 2005, rebounded between 2005 and 2015, and then dropped so that the rate in 2020 was at a level comparable to that in 2005 (0.7% [95% CI 0.7-0.7] for urban females, 2.2% [2.1-2.2] for rural females, 0.2% [0.2-0.2] for urban males, and 0.5% [0.5-0.5] for rural males). In urban areas, the fertility rate decreased from 10.1 per 1000 in 1990 to 2.4 (2.3-2.4) per 1000 in 2000, but then largely stabilised between 2000 and 2020. For rural adolescents, the fertility rate also decreased dramatically from 25.9 per 1000 in 1990 to 8.5 (8.2-8.8) per 1000 in 2005. The fertility rate rebounded to 15.4 (14.9-15.9) per 1000 in 2015 and decreased to 12.5 (12.3-12.7) in 2020 in rural areas. These three indicators greatly varied by province in 2020, with more negative patterns in western provinces. Interpretation: China has seen dramatic changes in adolescent education, and early marriage and fertility over the past three decades but large inequities persist between urban-rural areas and by province. Government investments are needed to promote education in rural areas and western regions to promote more equitable health, development and wellbeing in Chinese adolescents. Funding: National Nature Science Foundation of China.