Long-term use of the levonorgestrel-releasing intrauterine system

Since its launch in Finland in 1990, the levonorgestrel-releasing intrauterine system (LNG IUS) has become available in more than 100 countries throughout the world, with most countries also having the approval for the treatment of idiopathic menorrhagia and protection from endometrial hyperplasia during estrogen replacement therapy. After its introduction in Finland and Scandinavian countries, the LNG IUS has been available in most European countries since the mid to late 1990s and in the United States since 2001. Studies on the repeat use of the LNG IUS with second and third consecutive IUSs have shown high continuation rates and low rates of adverse effects. During repeat use of the LNG IUS, the bleeding pattern changes toward an increasing amenorrhea rate. With regard to the menorrhagia indication, the 5-year follow-up results of a randomized comparative trial of the LNG IUS and hysterectomy have shown equal satisfaction and improvement in health-related quality of life with both treatments. Although a proportion of women assigned to the LNG IUS group eventually underwent hysterectomy, the continuation rate of the LNG IUS for menorrhagia is clearly superior to that of conventional medical therapy (e.g., oral progestins). Use of the LNG IUS in combination with estrogen therapy in women undergoing menopausal transition seems to be well tolerated and associated with a favorable bleeding pattern.