Ma R, Luo Y, Wang J, et al. - Researchers conducted this retrospective cohort study to examine time trends of preterm birth and estimate the contributions of risk factors to the changes in preterm birth rates over a decade (2009–2018) of a transitional period in Shenzhen, China. Four hundred seventy-eight thousand forty-four live births were involved with sociodemographic and medical records for both women and infants. In total, 27,829 preterm births from 478,044 (5.8%) live births were registered and the preterm birth rate increased from 5.5% in 2009 to 6.2% in 2018. In an area under rapid sociodemographic transitions during 2009–2018, an uptrend of preterm birth rate was noted and the changes were correlated with these sociodemographic transitions. Continued investment in the education and prenatal care of girls has the potential to lower the preterm birth rate.