Effects of levonorgestrel‐releasing intrauterine system on recurrence and fertility outcomes during assisted reproduction after complete remission of early endometrioid endometrial cancer and precancerous lesions: A retrospective cohort study

To investigate the efficacy of the levonorgestrel-releasing intrauterine system (LNG-IUS) on recurrence and fertility outcomes during controlled ovarian stimulation (COS) in patients with early stage endometrioid endometrial carcinoma (EEC) and endometrial atypical hyperplasia (EAH) following successful fertility-preserving treatment. We reviewed the patients with Grade 1 presumed Stage IA EEC or EAH who underwent in vitro fertilization and embryo transfer after successful fertility-sparing treatment. A total of 176 women were enrolled in this study, undergoing 318 cycles of COS and 290 cycles of embryo transfer (ET). Twenty-one percent (37/176) patients have an LNG-IUS insertion during the initial ovarian stimulation, and the median follow-up time for this cohort was 61.3 months (interquartile range [IQR], 39.0-76.6 months), while it was 60.5 months for the other cohort (IQR, 44.9-80.3 months). Disease recurrence was experienced by 34.7% (61/176) of the patients. Compared to the non-LNG-IUS group, the LNG-IUS group had a lower recurrence rate 1 year after COS (5.4% (2/37) versus 20.9% (29/139), p = .034). The use of LNG-IUS was associated with a reduced recurrence rate 1 year after COS (hazard ratio = 0.203, 95% confidence interval [0.042-0.984], p = .048). The overall clinical pregnancy rate reached as high as 65.3% (115/176), while the cumulative live birth rates were up to 46.6% (85/176). We found that LNG-IUS during COS did not impact oocyte yield, ET, or pregnancy outcomes. The placement of LNG-IUS during COS in EEC/EAH patients is worth considering, as it is likely to reduce the recurrence of endometrial lesions without affecting fertility outcomes.