Long-acting gonadotropin-releasing hormone agonist trigger in fertility preservation cycles before chemotherapy

Abstract

Background: Oocytes/embryo cryopreservation and ovarian function suppression with gonadotropin-releasing hormone (GnRH) agonists (GnRHas) are two established strategies for preserving fertility in patients with cancer, frequently both being offered to the same woman. As the first injection of GnRHa should be administered before chemotherapy, it is usually performed in the luteal phase of the urgent controlled ovarian stimulation (COS) cycle. The GnRHa flare-up effect on recently stimulated ovaries may cause ovarian hyperstimulation syndrome (OHSS) and this risk may discourage some oncologists to offer an ovarian function preservation method with proven efficacy. We suggest the long-acting GnRHa as an option to trigger ovulation for egg retrieval in oncological patients, whenever ovarian suppression during chemotherapy is planned.

Patients and methods: We retrospectively analyzed prospectively collected data from all consecutive ovarian stimulation cases in oncological patients for oocyte cryopreservation from 2016 to 2021 in a single academic referral center. The COS was performed according to good clinical practice standards. Since 2020 long-acting GnRHa trigger was offered to all patients for whom ovarian suppression after cryopreservation was planned. All other patients served as controls, stratified for the triggering method used: highly purified chorionic gonadotrophin 10 000 UI or short-acting GnRHa 0.2 mg.

Results: Mature oocytes were collected, with the expected maturation rate, in all the 22 cycles triggered with GnRHa. The mean number of cryopreserved oocytes was 11.1 ± 4, with a maturation rate of 80% (57%-100%), versus 8.8 ± 5.8, 74% (33%-100%) with highly purified chorionic gonadotrophin and 14 ± 8.4, 80% (44%-100%) with short-acting GnRHa. No case of OHSS was observed after long-acting GnRHa triggering and by 5 days after egg retrieval most patients had reached luteinizing hormone levels showing suppression.

Conclusions: Our preliminary data show that long-acting GnRHa is efficacious in inducing the final oocytes' maturation, reducing OHSS risk and suppressing ovarian function by the start of chemotherapy.

Keywords: GnRH analog; OHSS; fertility preservation; oncofertility; oocyte cryopreservation.