Gestational hyperglycemia is defined as diabetes or varying degrees of abnormal glucose tolerance that occurs during pregnancy, that is, pregnancy first and diabetes later. It is mostly diagnosed in the 24thmdash;28th week of pregnancy. After delivery, most patients return to normal blood sugar and their diabetes symptoms disappear. About 20 percent of patients develop type 2 diabetes years or decades after delivery. Screening in the United States found that from 1991 to 2000, the prevalence rose from 5. 1% to 7. 4%, and the domestic literature reports domestic prevalence rates ranging from 5%-20%, also rising year by year. 1, diabetic patients planning pregnancy Control standards: blood glucose target value should be strictly controlled, pre-meal glucose control at 3.3-5.3mmol/L, post-meal glucose at 7.8mmol/L or less, HbA1c<6.5%. If insulin is applied, it can be relaxed appropriately and HbA1c<7.0% to prevent the occurrence of hypoglycemia. 2, diabetes found during pregnancy Control standard: the ideal target value is HbA1c<6.0%, the blood sugar before meal, bedtime and nighttime should not be higher than 5.3mmol/L, and the peak of 2 hours after meal is not higher than 6.7mmol/L. It is worth noting that the postprandial blood sugar control is more important than the preprandial blood sugar. The goal of blood glucose control for diabetic patients is not one-size-fits-all, but should be determined according to the specific situation of each individual. The general control target is the basis, and the principle of individualized setting of control target. In some cases, the target can be relaxed appropriately, and the key principle of adjusting the target is to control blood glucose while reducing the occurrence of hypoglycemia and avoiding excessive fluctuation of blood glucose. In conclusion, good blood glucose control should start from setting reasonable blood glucose control goals.