If swollen legs appear in the fourth month of pregnancy without other uncomfortable symptoms and no abnormal findings in blood tests, it is a physiological phenomenon. After pregnancy, the enlargement of the uterus will compress the inferior vena cava, resulting in poor venous circulation, which will produce swollen legs. As the number of weeks of pregnancy increases, blood dilution will occur and most pregnant women will have hypoproteinemia, which will also aggravate the swollen legs. If leg swelling is detected, it is important to monitor blood pressure and also check liver and kidney function. If there are no abnormal findings in these blood tests, pregnant women are advised to take proper rest, elevate both lower limbs to increase venous return, and take proper protein supplements, such as lean meat, eggs, and milk, which can all reduce the symptoms of edema.