Can the patient become sterile from just one insertion? It is possible. However, research shows that patients having 2 insertions were half as likely to become pregnant as patients who only had one insertion. If the patient cannot return for a second insertion four weeks after her first, she should go to the clinic or call her doctor for advice on what to do. Until she returns for a second insertion, she is still susceptible to become pregnant; therefore, she should continue to use another contraceptive method.