Objective: This study was designed to evaluate the potential usefulness of the levonorgestrel-releasing intrauterine device (LNG - IUD ; Mirena®) in treating women with uterine myomas.
Design: Prospective before-and-after (comparing) study.
Setting: Department of Obstetrics and Gynecology King Chulalongkorn Memorial Hospital.
Subjects: Sixteen women with uterine myomas who intended to receive treatment with the LNG IUD.
Intervention(s): Clinical and ultrasound examinations were performed prior to and at 1, 3 and 6 months after the LNG IUD insertion.
Main Outcome Measures: Myoma and Uterine volume, menstrual blood loss assessed with pictorial blood loss assessment charts and hematocrit.
Results: Use of the LNG IUD was associated with a statistically significant reduction in the total myoma volume, average uterine size and marked reduction in menstrual blood loss. After 6 months of use, the median total myoma volume decreased from 19.82 mL to 11.63 mL (p < 0.05), median pictorial blood loss assessment chart score declined from 89 to 3 (p < 0.05). Hematocrit level increased over 6 months of use. The most common side effects were bleeding disturbances (68.8%). No pregnancies occurred during the study.
Conclusion: The LNG IUD was associated with a profound reduction in myoma and uterine volume. For women with myomas of this size, the LNG IUD provides effective medical treatment of bleeding.

Keywords: Levonorgestrel, IUD, Uterine myoma, Menstrual bleeding