Ovarian tissue cryopreservation can be combined simultaneously with oocyte retrieval after controlled ovarian hyperstimulation

Abstract STUDY QUESTION Can ovarian tissue cryopreservation (OTC) be performed after controlled ovarian hyperstimulation (COH)? SUMMARY ANSWER Unilateral oophorectomy after transvaginal oocyte retrieval is feasible on stimulated ovaries during one surgical step. WHAT IS KNOWN ALREADY In the fertility preservation (FP) field, the timeframe between patient referral and start of curative treatment is limited. Combining oocyte pick-up with ovarian tissue (OT) extraction has been reported to improve FP but COH applied before OT extraction is not currently recommended. STUDY DESIGN, SIZE, DURATION This retrospective cohort-controlled study involved 58 patients who underwent oocyte cryopreservation immediately followed by OTC between September 2009 and November 2021. The exclusion criteria were a delay between oocyte retrieval and OTC of >24 h (n = 5) and IVM of oocytes obtained ex vivo in the ovarian cortex (n = 2). This FP strategy was performed either after COH (stimulated group, n = 18) or after IVM (unstimulated group, n = 33). PARTICIPANTS/MATERIALS, SETTING, METHODS Oocyte retrieval followed by OT extraction on the same day was performed either without previous stimulation or after COH. Adverse effects of surgery and ovarian stimulation, mature oocyte yield and pathology findings of fresh OT were retrospectively analysed. Thawed OTs were analysed prospectively, for vascularization and apoptosis using immunohistochemistry, when patient consent was obtained. MAIN RESULTS AND THE ROLE OF CHANCE No surgical complication occurred after OTC surgery in either group. In particular, no severe bleeding was associated with COH. The number of mature oocytes obtained increased after COH (median = 8.5 (25% = 5.3–75% = 12.0)) compared to the unstimulated group (2.0 (1.0–5.3), P