Under normal circumstances, the placenta should be greater than 5 cm from the inner cervical opening. if the placenta is 2 cm from the inner cervical opening, it is considered to be too low. In this case, you should pay attention and observe if there is any bleeding. If the placenta is low before 28 weeks, there is a possibility of upward migration. You should pay attention not to stand for a long time and take bed rest. When you are resting in bed, you can put your buttocks up appropriately to facilitate the upward movement of the placenta. After 28 weeks of pregnancy, the position of the placenta is fixed and there is no possibility of upward migration. If the placenta is still low, you should pay attention to it. During this period, you should not have sexual intercourse, stand for a long time or overexert yourself, otherwise it will cause bleeding. Because of the low placenta position, recurrent vaginal bleeding may occur at any time.