A Behavioral Intervention to Prevent Gestational Diabetes Mellitus

Participates will be recruited from five research centers in the mainland of China. Pregnant women will be screened for risks of GDM at their first visit for prenatal care during their first trimester (less than 12 gestational weeks). Obstetricians will introduce the study to women who have one or more risk factors. Women who meet the eligibility criteria and who are willing to provide informed consent will be enrolled and randomized to behavioral intervention group and control group. Women in the behavioral intervention group will be educated about the risks of GDM, and then applied with a mobile APP that provides nutrition, exercise and phycological support starting from their first trimester. This behavioral support will be modified individually and continuously according to the pregnant women's feedback of their daily performance through the APP. Both groups will have regular prenatal care. During 24‐28 gestational weeks, GDM will be diagnosed by a 75g oral glucose tolerance test (OGTT) according to the new World Health Organization criteria as fasting glucose level in fasting whole blood ≥5.1mmol/L, or 1‐hour value ≥10.0mmol/l, or 2‐hour value ≥8.5mmol/L. Investigators will compare the GDM risk in the two groups to evaluate whether behavioral intervention with mobile APP can reduce the risk of GDM in Chinese pregnant women who are at high risk of GDM. Participants' adherence with the behavioral intervention will be evaluated by analyzing the data collected by the APP, and participants' satisfaction of the prenatal care will be evaluated with questionnaires during 24‐28 gestational weeks. Intervention with the APP will be stopped in the third trimester. All the participates will receive standard medical management until they give birth.