This randomized, open-label, controlled trial was conducted at a medical center in Shanghai, China. Women with symptoms of postmenstrual
spotting after cesarean delivery, with a niche depth of at least 2 mm and residual myometrium of at least 2.2 mm on magnetic resonance imaging, and no intention to conceive within the next year were randomly assigned to receive treatment with 52-mg
levonorgestrel intrauterine system or hysteroscopic niche resection. The primary outcome was the reduction in postmenstrual
spotting at 6 months after randomization, defined as the percentage of women with a reduction of at least 50% in
spotting days relative to baseline. Efficacy and safety were assessed using intention-to-treat analysis.
RESULTS: Between September 2019 and January 2022, 208 women were randomized into the
levonorgestrel intrauterine system group (N=104) or the hysteroscopic niche resection group (N=104). At the 6-month follow-up, a 50% reduction in
spotting had occurred in 78.4% (80/102) of women in the
levonorgestrel intrauterine system group and in 73.1% (76/104) of women in the hysteroscopic niche resection group (relative risk, 1.07 [95% confidence interval, 0.92-1.25]; P=.370).
Spotting decreased over time (Ptrend=.001), with a stronger reduction observed in the
levonorgestrel intrauterine system group (P=.001). There was also a significant interaction between time and treatment (P=.007). From 9 months onward, a more significant reduction in
spotting was observed in the
levonorgestrel intrauterine system group than in the hysteroscopic niche resection group (9 months, 89.2% vs 72.1%; relative risk, 1.24 [95% confidence interval, 1.08-1.42]; 12 months, 90.2% vs 70.2%; relative risk, 1.29 [95% confidence interval, 1.12-1.48]). Moreover, compared with the hysteroscopic niche resection group, the
levonorgestrel intrauterine system group had significantly fewer postmenstrual
spotting days and total
bleeding days from 6 months onward (all P<.001), and less
pelvic pain from 3 months onward (all P<.010). No intervention-related complications were reported in any group. During follow-up, 11 (10.8%) women reported
hormone-related side effects, and 2 women (2.0%) in the
levonorgestrel intrauterine system group had spontaneous partial expulsion. Meanwhile, 3 unintended pregnancies were reported in the hysteroscopic niche resection group.
CONCLUSION: In women with niche-related postmenstrual
spotting, the
levonorgestrel intrauterine system was not more effective than hysteroscopic niche resection in reducing the number of
spotting days by at least 50% at 6 months. However, the
levonorgestrel intrauterine system was superior in reducing
spotting from 9 months onward, and it reduced the absolute number of
spotting days from 6 months onward and
pelvic pain from 3 months onward.