Su FL, Lu MC, Yu SC, et al. - Researchers performed this population-based retrospective cohort study to investigate the trend in the annual crude prevalence of gestational diabetes mellitus (GDM) and associated risk factors in Taiwan, as well as to reflect the magnitude of GDM as a major public health problem. Between January 1, 2004, and December 31, 2015, a total of 2,468,793 births from 2,430,307 pregnancies were reported. Finally, 2 053 305 pregnancies were included for further examination. During the 12 years from 2004 to 2015, the annual prevalence of GDM increased by 1.8 times, with a significant continuous increasing trend (from 7.6% to 13.4%). The annual prevalence of GDM increased significantly in each age group, especially for women with maternal ages of 31 years and older. Seasonal variations, urbanization level, and geographic risk factors were also noted.