The scarcity of evidence regarding the interchangeable use of different progestogens poses challenges, particularly in international egg donation and fertility preservation programs where standardizing protocols is crucial for achieving consistent efficacy, efficiency, and safety outcomes. Consequently, there's a pressing need for clinical studies to assess the effects of various progestogens on clinical outcomes in controlled ovarian hyperstimulation cycles. This study, a pioneering effort, aims to compare the effects of two progestogens on oocyte performance, safety, and efficiency in an egg donation program involving young, healthy, normo-responding patients.

This is a multicenter, randomized, controlled clinical study comparing two different progestogens for pituitary suppression in normo-responding patients undergoing controlled ovarian hyperstimulation (COH) for egg donation. Patients will be recruited on the day they begin the egg donation program. Before inclusion, patients must meet all inclusion and exclusion criteria and provide written informed consent. Each patient will be assigned a patient code based on the treatment group they are included in. Treatment with the assigned progestogens will start on the first day of COH. The standard protocol for egg donation will be followed, including stimulation with FSHr (Puregon®), pituitary suppression with either Medroxyprogesterone acetate (Progevera®) or Desogestrel (Cerazet®), and trigger with GnRH agonist (Triptorelin acetate, Decapeptyl®) 36 hours before oocyte retrieval. Patients will continue taking the assigned progestogen throughout the COH period. Oocyte quality will be assessed based on maturity and morphology, with mature oocytes classified as normal or good quality and abnormal oocytes categorized into intracytoplasmic and extracytoplasmic abnormalities. Quality assessment will be performed by two blinded embryologists.

Inclusion Criteria:

• BMI of 18-29,9 kg/m2
• Ultrasound count of antral follicles prior to COH ≥ 12 follicles
• Meeting the criteria for inclusion in the egg donation program
• Normal karyotype and no active sexually transmitted diseases
• No use of combined hormonal contraceptives one month before COH

Exclusion Criteria:

• Patients excluded from the egg donation program
• Untreated sexually transmitted diseases, positive serology for HBV, HIV, HCV
• Blood disorders, neurodegenerative/psychiatric diseases, carriers of X-linked genetic diseases, oncological diseases, endometriosis.
• Oligomenorrhea (<1 menstrual cycle in 3 months)
• Use of combined hormonal contraceptives before COH