Background: This study was conducted to determine causes of abnormal bleeding patterns occurring after at least 6 months of successful use of the levonorgestrel-releasing intrauterine system (LNG-IUS).
Study design: Matched-pair, case-control study. Fifteen users of the device with unacceptable bleeding problems (cases) and 15 controls using the device but without such problems were recruited. All women had vaginal ultrasonography and hysteroscopy performed to evaluate the endometrial cavity.
Results: An abnormality demonstrated by ultrasonography or hysteroscopy (either device displacement or leiomyomas) was more common among cases than controls. The McNemar's test for discordant case-control pairs yielded a p value of .046. After removal of the device and reinsertion of another levonorgestrel-releasing device, all cases reported improvement of the bleeding pattern.
Conclusions: Displacement of the device and intracavitary leiomyomas are commonly associated with unacceptable bleeding in women after prolonged use of the LNG-IUS. Ultrasonography and hysteroscopy may be useful in evaluating bleeding complaints in long-term users of this device.