Comparing the effectiveness of two levonorgestrel-releasing intrauterine systems for treating abnormal uterine bleeding

INTERVENTION: This is a randomized, controlled, parallel‐group, therapeutic equivalence clinical trial, single‐blind for participants, designed to evaluate the clinical efficacy and acceptability of two levonorgestrel‐releasing intrauterine systems for the treatment of abnormal uterine bleeding. A total of 120 women aged 18 to 55 years with a clinical diagnosis of abnormal uterine bleeding will be recruited from the gynecology outpatient clinics of the Hospital das Clínicas of the Federal University of Minas Gerais, the coordinating center, and the Maternidade Odete Valadares of the Fundação Hospitalar do Estado de Minas Gerais, the co‐participating center. Participants will be randomly allocated in a one‐to‐one ratio using a computer‐generated sequence with variable block sizes and stratification by participating center. Allocation concealment will be ensured using opaque, sealed, and sequentially numbered envelopes, which will be opened only at the time of the intervention. Participants will remain blinded to the type of intrauterine system inserted, while the professionals responsible for insertion and clinical follow‐up will not be blinded because of differences between the devices and their insertion procedures. The experimental group will include 60 participants who will undergo a single outpatient insertion of the intrauterine system releasing 19.5 milligrams of levonorgestrel. The active control group will include 60 participants who will undergo a single outpatient insertion of the intrauterine system releasing 52 milligrams of levonorgestrel. In both groups, insertion will be performed by trained and supervised professionals using a standardized aseptic technique. Participants in both groups will be followed for 12 months and will attend si Xclinical visits: a baseline assessment before insertion, a visit for intrauterine system insertion, and follow‐up visits at 1, 3, 6, and 12 months after insertion. The baseline visit will include clinical assessment, application of the Pictorial Blood Assessment Chart, the Menstrual Bleeding Questionnaire, and the 36‐Item Short Form Health Survey, laboratory tests, and transvaginal ultrasound. At the insertion visit, the allocated intrauterine system will be inserted in an outpatient setting. At the 1‐month visit, participants will undergo clinical assessment and transvaginal ultrasound to evaluate device positioning. At the 3‐month visit, menstrual bleeding, adverse events, clinical outcomes, and treatment satisfaction will be assessed. At the 6‐month and 12‐month visits, menstrual bleeding, quality of life, laboratory parameters, adverse events, clinical outcomes, and treatment satisfaction will be reassessed. Routine clinical care will be maintained throughout the study CONDITION: C12.050.351.500.852.691 Menorrhagia ; Uterine Hemorrhage PRIMARY OUTCOME: It is expected that the 19.5‐milligram levonorgestrel‐releasing intrauterine system will be therapeutically equivalent to the 52‐milligram levonorgestrel‐releasing intrauterine system in reducing menstrual bleeding at 12 months, as assessed by the change in the Pictorial Blood Assessment Chart score from baseline to 12 months, with equivalence confirmed if the 95 percent confidence interval for the between‐group difference is entirely contained within the predefined equivalence margin of minus 22 to plus 22 points. SECONDARY OUTCOME: It is expected that both groups will show improvement in laboratory indicators associated with menstrual blood loss, assessed by changes in hemoglobin, serum iron, ferritin, and transferrin values from baseline to 6 and 12 months, with comparison of the mean changes between the groups receiving the 19.5‐milligram and 52‐milligram levonorgestrel‐releasing intrauterine systems. It is expected that both groups will show improvement in quality of life and in the impact of menstrual bleeding on daily activities, assessed by changes in the Menstrual Bleeding Questionnaire and the 36‐Item Short Form Health Survey scores from baseline to 6 and 12 months, with comparison of the mean changes between the groups, while treatment satisfaction will be assessed at 12 months by the proportion of participants reporting satisfaction with the received treatment. It is expected that the frequencies of amenorrhea and adverse events associated with device use will be similar between the groups receiving the 19.5‐milligram and 52‐milligram levonorgestrel‐releasing intrauterine systems, assessed by the number and proportion of participants presenting each event at 1, 3, 6, and 12 months after insertion. INCLUSION CRITERIA: Female participants aged 18 to 55 years; clinical diagnosis of abnormal uterine bleeding defined by a score of 100 or higher on the Pictorial Blood Assessment Chart; clinical indication for conservative treatment with a levonorgestrel‐releasing intrauterine system; provision of written informed consent