This study will examine whether or not pretreatment with oral norethindrone acetate prior to the insertion of a hormonal intrauterine device will affect post-insertional uterine bleeding. The subjects enrolling in the study will have documented heavy menstrual bleeding (HMB) and desire the levonorgestrel intrauterine system (LNG IUS) (Mirena®, Bayer, Inc. Pittsburgh, PA) for symptomatic relief. HMB for this study is defined as heavy bleeding at regular intervals at least 20-40 days apart. Subjects will be randomized to one of two groups. One group will receive norethindrone acetate for two consecutive months prior to LNG IUS insertion while the other group will proceed with direct insertion of the LNG IUS with no hormonal pre-treatment. Subjects will be followed for a period of 180 days post LNG IUS insertion. Bleeding patterns will be recorded daily.
Problematic uterine bleeding after the insertion of the LNG IUS is a well documented side effect. The levonorgestrel intrauterine system (LNG IUS) was approved for treatment of heavy menstrual bleeding (HMB) by the FDA in October 2009. To reduce the incidence and severity of post-insertional uterine bleeding, pretreatment with norethindrone acetate may effectively slough the endometrium prior to insertion of the LNG IUS.