Objective:To investigate the risk factors of Gestational Diabetes Mellitus(GDM)in primipara and the value of metformin therapy.Methods:78 pregnant women with GDM treated in our hospital from September 2021 to August 2023 were selected as the GDM group,and 78 pregnant women without GDM were selected as the non-GDM group during the same period.Clinical data of the two groups of pregnant women were collected,including age of pregnant women,monthly family income,Body Mass Index(BMI)before pregnancy,educational background,whether they were the only child,family history of diabetes,method of conception of this pregnancy,smoking history,history of polycystic ovary syndrome,and vaginal bleeding 3 months before pregnancy,etc.The risk factors were analyzed by univariate and multivariate Logistic regression.According to different treatment methods,pregnant women with GDM were divided into observation group(n=39 cases,treated with metformin)and control group(n=39 cases,treated with conventional clinical treatment).The levels of glucose and lipid metabolism indexes,pregnancy outcomes and treatment satisfaction of the two groups were compared.Results:Univariate analysis showed that there were significant differences in age,BMI before pregnancy,family history of diabetes and age of menarche between the two groups(P<0.05).Multivariate Logistic regression analysis showed that:age>35 years old(OR=4.697,95%CI:2.855~7.728),pre-pregnancy BMI ≥24kg/m2(OR=2.965,95%CI:2.055~4.278),family history of diabetes(OR=2.396,95%CI:2.093~2.774)were high risk factors for GDM in primipara.After treatment,the levels of glucose and lipid metabolism indexes in both groups were decreased,and the observation group was lower than the control group(P<0.05).The total incidence of adverse pregnancy outcomes in the observation group was 15.38%,which was lower than that in the control group 38.46%.The total satisfaction of the observation group was 94.87%,higher than that of the control group 79.49%,and the difference was statistically significant(P<0.05).Conclusion:Age,pre-pregnancy BMI and family history of diabetes are independent risk factors for GDM in primipara.Treatment with metformin regimen can effectively improve glucose and lipid metabolism,reduce the incidence of adverse pregnancy outcomes and improve treatment satisfaction.