Pregnant women control sugar weight loss, if the decline is not much, weight within the normal range, generally have no effect on the fetus; but if the decline is too fast or excessive dieting, it will affect the development of the fetus. Pregnant women need strict control of blood sugar during pregnancy, through diet, exercise and medication can be effective in controlling blood sugar, during which there will be a corresponding decline, which is a normal phenomenon, generally does not have a great impact on pregnant women and the fetus. However, some pregnant women, in order to achieve the purpose of glycemic control, excessive diet or exercise, it is easy to make the blood sugar too low and cause dizziness, nausea, vomiting and other symptoms of hypoglycemia, and even fainting, thereby increasing the risk of miscarriage; and if the weight loss is too high, the risk of miscarriage will be increased. And if the weight loss is too fast, the body malnutrition is easy to make the fetus development by. It is recommended that pregnant women monitor their blood glucose regularly during the sugar control period so as to avoid too rapid a drop in blood glucose.