The normal value of fasting blood glucose is 3.9-6.1mmol/L. Diabetes is diagnosed when the fasting blood glucose is greater than or equal to 7.0mmol/L on 2 or more occasions. Diabetes is easily complicated by various acute and chronic complications, such as diabetic nephropathy, diabetic foot, diabetic fundopathy, diabetic ketoacidosis, etc. It seriously affects the quality of life of patients and even shortens their healthy life span. Therefore, it is necessary to actively control blood sugar to keep it within the normal range, prevent or delay the occurrence of diabetic complications, and better improve the quality of life of patients. The standard of fasting blood sugar for pregnant women is different from that of normal people, and the normal value is between 3.1 and 5.1 mmol/L.