Abstract
The mechanism of action and adverse reactions of 52 mg levonorgestrel-releasing intrauterine system and also level of pain during the insertion and techniques of anesthesia or analgesia for this procedure have been well documented. On the opposite pole the 13.5 levonorgestrel-releasing intrauterine system has been recently launched in Europe. To our knowledge there are no studies correlating the device design and biomaterials, mechanism of action, surgical technique and level of pain during the insertion of levonorgestrel-releasing intrauterine systems. This study was undertaken in order to determine whether there is a different level of pain during the insertion of 52 mg levonorgestrel-releasing intrauterine system compared to 13.5 mg levonorgestrel-releasing intrauterine system, considering the mechanism of action and the structural and dimensional discrepancies between the two intrauterine devices. Keywords: Levorgestrel-releasing intrauterine systems, device design, mechanism of action, level of pain during the insertion