How much is the lower edge of the placenta normal from the internal opening of the cervix

Generally, the distance between the lower edge of the placenta and the internal opening of the cervix is about three centimeters to five centimeters. If the lower edge of the placenta is more than six centimeters away from the internal opening of the cervix, it generally indicates that the placenta is more likely to be previa, which may cause placental detachment, thus leading to massive bleeding symptoms. The patient had better take timely measures.