Levonorgestrel intrauterine system vs. hysteroscopic niche resection for postmenstrual spotting: a three-year randomized trial follow-up

Building on previous findings demonstrating that both the 52-mg levonorgestrel intrauterine system (LNG-IUS) and hysteroscopic niche resection significantly reduced niche-related postmenstrual spotting, with over 70% of patients achieving ≥50% reduction at six months and LNG-IUS showing superior efficacy beyond 9 months, this study evaluates the long-term effectiveness of both treatments in reducing niche-related postmenstrual spotting over36 months. This three-year follow-up stems from a single-center randomized trial. Women experiencing postmenstrual spotting after cesarean delivery, with Magnetic Resonance Imaging (MRI) -confirmed niche depth ≥ 2.0 mm and residual myometrium ≥ 2.2 mm, and without plans to conceive within one year, were randomized to receive either the 52-mg LNG-IUS or hysteroscopic niche resection. Main outcome of this long-term follow-up was the proportion of women achieving ≥50% reduction in spotting from baseline at 36 months. Secondary outcomes, including menstrual patterns, spotting discomfort, chronic pelvic pain, and satisfaction with treatment, were assessed at 18, 24, 30, and 36 months. A total of 208 women were randomized (104 in each group), with 93 (89.4%) in the LNG-IUS group and 89 (85.6%) in the hysteroscopic niche resection group completing the three-year follow-up. At 36 months, 98.9% of women in the LNG-IUS group and 51.7% in the hysteroscopic group achieved a 50% reduction in spotting (RR, 1.91 [95% CI, 1.56 - 2.34]; p < 0.001). Spotting decreased progressively over time in the LNG-IUS group through 36 months (Ptrend = 0.001), whereas the hysteroscopic group showed reduction only until 24 months (p=0.007), followed by a slight increase. A significant time-treatment interaction was observed (p = 0.007), with LNG-IUS demonstrating superior spotting reduction from 24 months onward Additionally, the LNG-IUS group had fewer postmenstrual spotting days, total bleeding days (p < 0.001), and less pelvic pain (p < 0.010) from six months onward, with the difference widening over time. During the follow-up, 20 women in the LNG-IUS group reported hormone-related side effects, and two experienced partial expulsions. In the hysteroscopic group, five pregnancies were reported (three unintended, two planned) CONCLUSION: Over36 months, the 52-mg LNG-IUS was superior to hysteroscopic niche resection for reducing postmenstrual spotting, pelvic pain, and discomfort, while also offering contraceptive benefits in women with symptomatic niche. We recommend LNG-IUS as a first-line treatment for niche-related spotting in reproductive-age women with no fertility desire for at least the next year.