Gestational diabetes refers to diabetes that appears during pregnancy, or is detected during pregnancy, or is an abnormal glucose tolerance of any degree. Gestational diabetes affects both the pregnant mother and the fetus. Although the mortality rate of pregnant women with gestational diabetes has significantly decreased, complications are still quite common. It may increase the rate of spontaneous miscarriages and preterm births for fetuses. Secondly, it can cause fetal or neonatal death, and intrauterine growth retardation. Thirdly, it leads to excessive amniotic fluid and macrosomia, and may result in neonatal polycythemia, fetal malformations, neonatal respiratory distress syndrome, neonatal hypoglycemia, as well as neonatal hypocalcemia and hypomagnesemia. For the mother, it can lead to pregnancy-induced hypertension syndrome, infections during pregnancy or childbirth, and in severe cases, diabetic ketoacidosis.