Sugar screening can still be done at 29 weeks of pregnancy, but it is better to do it at 24-28 weeks of gestation because various insulin-fighting hormones secreted by the placenta rise rapidly at 24-28 weeks of gestation and reach a peak at 32-34 weeks of gestation, so if the best time for testing is missed, i.e., beyond 28 weeks, sugar screening should also be done. In addition, if a pregnant woman has a family history of diabetes or has high blood glucose in the past, and if she is obese or eats high-calorie foods frequently, it is even more recommended to have a glucose screening test in advance so that abnormal blood glucose can be detected and treated early. At present, the screening method is not completely uniform throughout the country, and there are 2 methods. Some first do the first method of initial screening, and then do the second test if there are problems, and some directly choose the second method: Method 1, pregnant women should ensure a 12-hour fasting state before doing the glucose screening test, and drink 200ml of water containing 50g of glucose within 5 minutes, and measure the blood glucose value after 1 hour, if the result is ≥7.8mmol/L, the glucose screening is abnormal, and further glucose tolerance test is needed . Method 2, glucose tolerance test should also ensure fasting for 12 hours, and first fasting blood to check blood sugar, then add 150ml of 50% glucose injection into 100ml of water, or dissolve 75g of glucose powder in 300ml of water, drink it within 5 minutes, start timing from the first sip, and draw blood to check blood sugar after 1 hour and 2 hours, the normal value standard is fasting blood sugar 5.1mmol/L, 1 The normal values are fasting blood glucose 5.1mmol/L, 1 hour blood glucose 10.0mmol/L, 2 hour blood glucose 8.5mmol/L. If one of these values reaches or exceeds the normal value, gestational diabetes can be diagnosed. If gestational diabetes is diagnosed, pregnant women must pay attention to their diet, monitor their blood glucose regularly, and keep their blood glucose levels strictly below normal values so as to ensure the health of the mother and fetus to the greatest extent possible.