The lack of weight gain at 15 weeks of pregnancy is a common condition during pregnancy, which can be caused by early pregnancy reaction or malnutrition, and most of them do not need special treatment. However, we need to pay attention to the presence of other accompanying symptoms to exclude hyperthyroidism or some consumptive diseases. 1.Physiological factors: Most pregnant women in early pregnancy may have early pregnancy reaction due to the rise of HCG level, causing nausea, vomiting and difficulty in eating, etc. Early pregnancy reaction may be too serious and may lead to severe pregnancy vomiting. The amount of food eaten at this stage is relatively small, which can lead to weight loss. With the progress of pregnancy, early pregnancy reaction can gradually reduce to disappear, and the weight of pregnant women will rise after their appetite increases; 2, malnutrition: pregnant women can’t get nutrition due to factors such as poor appetite or worry about becoming fat, and there is malnutrition, which makes it difficult to meet the nutrient demand of the body and fetus, and the weight of pregnant women themselves will not increase; 3, other factors: combined with hyperthyroidism during pregnancy, pregnant women can have The symptoms include enlarged thyroid gland, irritable fever, easy sweating, impatient and irritable temperament, protruding eyes and hand trembling, etc. Due to the high metabolic state of the body during hyperthyroidism, there will also be no weight gain at 15 weeks of pregnancy; in addition, some wasting diseases, such as tuberculosis and tumors, will also cause extreme body wasting in the late stage, so pay attention to the screening. Under normal circumstances, the weight gain throughout pregnancy depends on the pre-pregnancy BMI. If the pre-pregnancy BMI is in the normal range, it is recommended that the weight gain should not exceed 12.5kg throughout pregnancy, and 1-2kg can be increased in early pregnancy, but if there is no weight gain, there is no need to worry excessively. In addition, we should pay attention to regular eating habits during pregnancy, strengthen the nutrient supplementation, and adjust the diet according to the pregnant woman’s taste to promote appetite when her appetite is poor.