The levonorgestrel IUD.

A levonorgestrel (LNG)-releasing IUD (called the MIRENA LNG-releasing intrauterine system) that has been widely used in Europe has become available in the US. It consists of a polyethylene T frame surrounded by a LNG-containing cylinder and combines advantages of both hormonal and intrauterine contraception. Results of several large European studies have demonstrated the safety and efficacy of the LNG-IUD noting that the LNG-IUD has the same low pregnancy rate in every age group of users. A long-acting reversible contraceptive method with a pregnancy rate comparable to female sterilization the LNG-IUD provides several therapeutic benefits. These include increased reduction of menstrual blood loss thus providing an effective treatment for menorrhagia and causing an increase in hemoglobin concentration leading to a reduction in the risk of anemia in fertile women. A significant reduction in the incidence of uterine fibroids and dysmenorrhea has also been reported among users of the LNG-IUD. However some systemic hormonal effects may result from circulating LNG levels of about 150 pg/ml which include headache mastalgia nausea acne hirsutism depression and mood changes. Like the Copper T 380A IUD the LNG-IUD is a highly effective contraceptive that is rapidly reversible.