Edema during pregnancy may be physiological edema, or it may be caused by hypoproteinemia, gestational hypertension and other reasons. 1. Physiological edema: with the gradual growth of pregnancy weeks, the abdominal circumference of pregnant women and the size of the fetus also increased significantly, will be easy to the inferior vena cava caused by compression, resulting in poor venous return, the emergence of edema during pregnancy. 2. Hypoproteinemia: If the daily intake of protein of pregnant women is relatively small, it may lead to malnutrition, underfeeding, etc., causing the nutrients can not be adequately absorbed, resulting in the occurrence of hypoproteinemia and the phenomenon of edema during pregnancy. 3. gestational hypertension: some pregnant women during pregnancy, combined with gestational hypertension, will have an impact on kidney function, resulting in increased protein elimination with urine, resulting in the body of water infiltration into the interstitial space of the local tissues, the emergence of edema in pregnancy. Edema in pregnant women to exclude physiological edema, should promptly go to the hospital obstetrics consultation, clear cause of the disease under the guidance of the doctor to carry out appropriate treatment.