Donor side effects experienced under minimal controlled ovarian stimulation (COS) with in vitro maturation (IVM) versus conventional COS for in vitro fertilization (IVF) treatment

Objective To evaluate oocyte retrieval experiences and side effects under minimal controlled ovarian stimulation (COS) for in vitro maturation (IVM) compared to conventional COS. Design Retrospective Survey Study Setting Clinical in vitro fertilization (IVF) treatment center in Spain. Subjects Data were collected from subjects undergoing minimal COS (n=110; 600-800 IU FSH) for IVM and conventional COS for egg donation (n=48; 1800-2600 IU FSH) from April 2022 to November 2023. Intervention/Exposure Minimal and conventional controlled ovarian stimulation. Main Outcome Measures The most common side effects suffered during ovarian stimulation and after OPU, satisfaction level, and the likelihood of recommending or repeating minimal or conventional COS. Statistical analysis included Mann Whitney and Chi-square tests, with a significance level set at p<0.05. Results During minimal COS, most subjects did not experience breast swelling (86%), pelvic or abdominal pain (76%), nausea or vomiting (96%), and bleeding (96%). After oocyte pick-up, the majority (75%) reported no pelvic or abdominal pain. The most common side effect was abdominal swelling (52%). Compared to conventional COS cycles, minimal COS subjects reported significantly less post-retrieval pain, with 33% experiencing no pain (vs. 6%; p=0.0011) and with a reduced severe level of pain (5% vs.19%; p=0.0097), leading to fewer subjects requiring pain medication (25% vs. 54%; p=0.0003). Additionally, 85% of women were very satisfied with minimal stimulation and would recommend or repeat the treatment. Conclusion Reducing the hormonal dose for ovarian stimulation has a beneficial effect on subjects, suggesting the combination of minimal COS with IVM techniques is a well-tolerated alternative for women who cannot or do not wish to undergo conventional controlled ovarian hyperstimulation.