Open bony suture refers to the middle and late stages of pregnancy, when the level of relaxin in the body increases, resulting in laxity and separation of the ligaments of the joints of the woman, the woman’s joints are unstable, and more serious pain occurs. Most of the pain is related to a specific position. With the prolongation of time after delivery, the pain and discomfort caused by the ligament laxity will slowly ease, so there is no need to worry too much. The opening of the bones can cause very severe pain or other discomfort. In most cases, there is a transient connection between the bones in the late stages of pregnancy, and the joints and ligaments will loosen accordingly, which will gradually improve with time.