Gestagens as an alternative to GnRH antagonists in ovarian stimulation protocols in oocyte donors and cancer patients

Abstract

Objective. To compare the parameters of folliculogenesis and early embryogenesis in oocyte donors participating in IVF programs with donor oocytes (IVF-DO) and in patients with neoplastic diseases undergoing fertility preservation programs, when dydrogesterone or the GnRH antagonist (cetrorelix) is administered in stimulated cycles to prevent sudden luteinizing hormone (LH) surges. Patients and methods. To prevent premature luteinization in stimulated IVF-DO cycles and to preserve fertility in patients with neoplastic diseases, dydrogesterone (20 mg/day) or cetrorelix (0.25 mg/day) was administered in a flexible regimen (from the moment the dominant follicle reached a diameter of 14 mm until the day of ovulation trigger). In the IVF-DO program, dydrogesterone and cetrorelix were administered to 26 and 28 oocyte donor women, respectively; in the fertility preservation program, to 14 and 20 patients with neoplastic diseases, respectively. The study endpoint was the assessment of the association between the parameters characterizing folliculogenesis (number of stimulation days, total dose of follicle-stimulating hormone (FSH), total number of cumulus-oocyte complexes (COCs) and mature MII oocytes retrieved, oocyte maturity rate, and estradiol levels on the day of ovulation trigger) and early embryogenesis (fertilization rate, mean number of zygotes and blastocysts obtained, blastocyst formation rate, and good-quality blastocyst formation rate) and the type of medication used to prevent sudden LH surges. Results. The use of dydrogesterone and cetrorelix to prevent sudden LH surges demonstrated comparable outcomes in oocyte donors participating in IVF-DO programs and in patients with neoplastic diseases undergoing fertility preservation programs. The parameters characterizing folliculogenesis and early embryogenesis showed no significant differences between both groups (p > 0.05 for all pairwise comparisons). Conclusion. In IVF-DO programs and fertility preservation programs in patients with neoplastic diseases, oral dydrogesterone and the parenterally administered GnRH antagonist (cetrorelix) were used in a flexible regimen during the gonadotropin stimulation phase. Both treatments provided comparable therapeutic efficacy during the pre-implantation phase of IVF in terms of parameters characterizing folliculogenesis and early embryogenesis. Key words: infertility, oncofertility, pre-transfer phase of IVF, premature luteinization, dydrogesterone, cetrorelix