ISO 11249:2018 provides guidance on the design and conduct of clinical studies to determine the performance characteristics of new intrauterine devices. It also provides advice on the analysis of data when the study is completed, as well as interpretation of these results by manufacturers, researchers and regulatory bodies. ISO 11249:2018 is intended to ensure the scientific conduct of the clinical investigation and the credibility of the clinical investigation results, and to assist sponsors, monitors, investigators, ethics committees, regulatory authorities and other bodies involved in the conformity assessment of medical devices. Certain clinical trial concerns are not addressed in this document, including subject compensation, confidentiality of subjects and their records, use of local ethics committees, etc. These and many other clinical trial design issues are covered in great detail in ISO 14155.