Gestational diabetes mellitus refers to any degree of abnormal glucose tolerance or overt diabetes mellitus that develops or is first detected during pregnancy is called gestational diabetes mellitus. Diabetes mellitus is a combination of diabetes mellitus and diabetic pregnancy if the diagnosis of diabetes mellitus was made before the pregnancy. The main risks of diabetic pregnancy are congenital malformations, macrosomia, birth defects, developmental and pulmonary maturation disorders, neonatal hypoglycemia in the fetus, and hypoglycemia, pre-eclampsia, and late complication progression in the mother. Therefore, patients with gestational diabetes mellitus should be followed up frequently, once every 2-4 weeks, and test their own blood glucose daily.