Ruiping Wang,1,* Qiong Yang,2,* Ting Sun,3,* Yan Qiang,1,* Xiaopan Li,4 Huan Li,3 Yue Tang,3 Liang Yang,5 Jie Sun,5 Bin Li1 1Clinical Research & Innovation Transformation Center, Shanghai Skin Diseases Hospital Affiliated to Tongji University, Shanghai, People’s Republic of China; 2Office of Public Health, Songjiang Fang Song Community Health Service Center, Shanghai, People’s Republic of China; 3Obstetrics and Gynecology Department, Songjiang Maternal and Child Health-Care Hospital, Shanghai, People’s Republic of China; 4Department of Non-Communicable Disease Control and Prevention, Pudong District Center for Diseases Control and Prevention, Shanghai, People’s Republic of China; 5Department of Women Health, Jing’an Institute of Maternal and Child Health-Care, Shanghai, People’s Republic of China*These authors contributed equally to this workCorrespondence: Ruiping WangClinical Research & Innovation Transformation Center, Shanghai Skin Diseases Hospital Affiliated to Tongji University, 1278 Baode Road, Jing’an District, Shanghai, 200443, People’s Republic of ChinaFax +86-21-3680 3000Email w19830901@126.comBin LiClinical Research & Innovation Transformation Center, Shanghai Skin Diseases Hospital Affiliated to Tongji University, 1278 Baode Road, Jing’an District, Shanghai, 200443, People’s Republic of ChinaEmail l8930568129@126.comObjective: Physical exercise during pregnancy is beneficial to women with gestational diabetes mellitus (GDM), but evidence on the association between physical exercise and glycemic control among women with GDM is limited in China. We conducted this study to understand the total exercise times, the percentage of abnormal plasma glucose (PG), and to explore if longer physical exercise is positively associated with a lower percentage of abnormal PG among GDM women.Methods: During 2019 and 2020, we established a prospective cohort with 1,050 GDM women recruited. GDM was confirmed by a diagnostic 75g OGTT, and plasma glucose in over 10 hours overnight fasting and 2-hour after breakfast was implemented during a routine antenatal checkup. Information for demographic features and physical exercises among GDM women were collected by questionnaire interviews, and abnormal PG percentage was calculated as abnormal PG times divided by total PG test times.Results: Among 1,050 GDM women, the percentage of exercise times < 150 minutes/week, < 30 minutes/day and < 60 minutes/day was 17.33%, 26.57%, and 54.10%, respectively. The median percentage of abnormal PG was 40% (IQR=20– 70%). GDM women with less exercise had a higher abnormal PG percentage (y=0.0049x2-1.20x+88.96), ORs for women with exercise < 150 minutes/week were 3.78 (95% CI=1.33– 8.25), 6.97 (3.45– 14.07), and 6.39 (3.61– 11.33) compared with ≥ 150 minutes/week, and ORs for women with exercise < 60 minutes/day were 4.62 (2.71– 8.14), 3.58 (2.60– 4.93), and 7.28 (4.31– 12.30) compared with ≥ 60 minutes/day in groups divided by quartiles of P25, P50 and P75, respectively.Conclusion: This study indicated high physical exercise times and abnormal PG percentage among women with GDM in Shanghai, China. GDM women with more exercise times had a lower percentage of abnormal PG, especially when exercise times were ≥ 60 minutes/day, and supplementary treatments should be provided for women with over 70% abnormal plasma glucose.Keywords: physical exercise, gestational diabetes mellitus, prospective cohort, association, glycemic control, abnormal plasma glucose