In late pregnancy, that is, in the second trimester of pregnancy, edema of the ankles occurs, and it is necessary to distinguish whether it is unilateral or bilateral. If it is unilateral, it is easy to be the formation of thrombus, because the blood is in a state of hypercoagulability during pregnancy, it is easy to form thrombus, so unilateral edema of the foot, you need to do the lower extremity vascular ultrasound to make a judgment, to exclude the existence of thrombus. If it is bilateral edema of the ankles, it may be a normal phenomenon caused by abnormal levels of estrogen and progesterone due to pregnancy. If it is not accompanied by increased foam in the urine or elevated blood pressure, it will disappear after the pregnancy is delivered. If it is accompanied by an increase in protein in the urine and elevated blood pressure, it may be hypertensive syndrome of pregnancy, and it is necessary to actively observe her closely to see if her symptoms worsen. When the labor and delivery period is over, there may be a significant relief, if not, it is necessary to take certain drugs for treatment, of course, can not breastfeeding while taking drugs.