Han L, et al. - Using the baseline data from the Tianjin Gestational Diabetes Mellitus Prevention Program, a retrospective cohort study was conducted to examine the interaction between genetic risk score of HbA_1c and weight changes during and after pregnancy(postpartum weight reduction and gestational weight gain) on long-term glycemic changes in the largest cohort of women with preceding history of gestational diabetes mellitus (GDM). One thousand, one hundred fifty-six women with preceding history of GDM were included in this analysis. Among women with preceding history of GDM, a genetic risk score of HbA_1c interact with postpartum weight reduction on long-term changes of HbA_1c.