Weight loss after sugar control during pregnancy is generally not affecting the fetus, but it must be controlled under the guidance of a doctor. Gestational diabetes mellitus may lead to adverse pregnancy outcomes, must be under the guidance of a doctor to control blood sugar, and to properly control the diet, limiting the intake of carbohydrates and fats and other foods, but to ensure that the intake of adequate proteins, vitamins and other substances, so although the weight will be lost, but generally does not affect the fetal development, but can not be over-dieting, or it will affect the growth of the fetus. For pregnant women with diabetes to strengthen the management of pregnancy, but also under the guidance of the doctor to ensure appropriate physical activity, such as half an hour after meals, appropriate walking, etc., when necessary, need to follow the doctor’s orders to give insulin to control blood glucose. Timely checkups, close monitoring of intrauterine fetal status and placental function to ensure the safety of mother and fetus during pregnancy.