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

Abstract 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.