The results of this study showed that the use of metformin as an oral hypoglycemic agent in gestational diabetes had no significant difference in glycemic control (fasting blood glucose, blood glucose, and glycosylated hemoglobin) compared with the utility of insulin injection, but the use of metformin could control maternal weight and improve pregnancy outcomes (reduce the rate of miscarriage and cesarean section). The gene discussed is INS; the disease is gestational diabetes.