If the birth control ring expires and is not removed, it is usually not cancerous, but it may affect the body, for example, it may cause infection in the uterine cavity, or lead to abnormal bleeding and so on. 1. Infection of the uterine cavity: As women age and hormone levels drop, the cervix and the uterine cavity will gradually shrink, but the birth control ring will not get smaller. It may be embedded inside the uterine muscle layer, leading to infection of the uterine cavity, abdominal pain, abdominal distension and other uncomfortable phenomena. 2. Abnormal Vaginal Bleeding: If the IUD is not removed in time, it may cause irregular menstruation or abnormal vaginal bleeding. The IUD has a service life of 5 to 15 years and needs to be removed when it reaches the end of its service life. If the IUD is not taken out when it expires, or even if it is not taken out for life, it is very harmful to the body. If the above situation occurs, it is recommended that the patient consult a doctor in time, and under the guidance of the doctor to carry out targeted treatment.