Comparison to other literature
The reduction effect of hysteroscopic niche resection on spotting in our study are in line with previous studies reporting a median reduction of 4 days at 3 to 6 months follow-up.11, 12, 17 Only one small study including only 6 patients evaluated the effect of LNG-IUD on spotting and reported a beneficial effect.18 None of the previous studies compared both interventions and none of these studies evaluated the changes in effectiveness over time in this population.
In a general population approximately 20% of amenorrhea is reported one year after insertion of LNG-IUD.22-25 In our population of regular menstruating patients with spotting and a niche, the rate of amenorrhea was higher, 39% at one-year follow up. Previous studies also reported higher rates, up to 25% of irregular bleeding 6 months after LNG-IUD insertion26, while only 11% or our patients reported irregular bleeding in the LNG-IUD group.
The strict clear selection criteria may have played a role in the reported differences between our study and previous studies, since women with an irregular menstrual cycle or endometrial atypia were exclusion criteria in our study. This is in line with the fact that previous studies have found in inverse relation between the thickness of the endometrium and the amenorrhoic rate.19, 27 In our study the proportion of women with amenorrhea increased over time, this is also in line with previous studies.19, 27