No, you can use it even if you have not had children. In fact, as the IUS is the most effective form of contraception available. Studies have found that some nulliparous users (women who have not had children) experiences slightly more pain and bleeding during insertion and removal of the device. The reason for this is that pregnancy helps stretch the uterus, and therefore nulliparous women's uterus is slightly smaller, potentially making it more difficult to fit the device. But a medical practitioner can anticipate and manage this at the time of the insertion.