GnRH Antagonist Ovarian Stimulation Protocol

For the GnRH-ant protocol, COH was started with 72.5–300 IU gonadotropin (Puregon, Organon, Netherlands) on day 2–3 of the menstrual cycle. The initial dose of gonadotropin was administered on the basis of the woman’s age, AFC, BMI, and ovarian response to stimulation. A daily dose of 0.25–0.75 mg GnRH antagonist (Cetrotide, Pierre Fabre, Aquitaine Pharm International) was initiated on the sixth day of rFSH stimulation or when the lead follicle reached a mean diameter of 12–14 mm, and the gonadotropin was continued until the day of the trigger administration (5000 IU u-HCG, Livzon Pharmaceuticals or 250 μg r-hCG, Merck Serono in combination with 2000 IU u-HCG). The Oocytes were then retrieved 35–37 h after the trigger (Li F. et al., 2020 (link); Figure 4).