P-CCROSS is a randomized, prospective monocentric phase 4 study with a crossover study design. The aim of the study is to compare patient satisfaction (by means of questionnaires) and treatment compliance with IVF treatment with CFA (corifollitropin alfa) and PPOS (Progestin-Primed Ovarian Stimulation) versus conventional IVF treatment with a recombinant FSH/GnRH antagonist. The study will also compare patients undergoing elective fertility preservation versus PGT-A (pre-implantation genetic testing for aneuploidy) patients.The study will have a crossover design so that patients will receive both forms of treatment. The investigators will also compare the endocrine profile and ovarian response of CFA/PPOS versus rFSH/GnRH ovarian stimulation cycles.

Prescreening: Clarification: Pre-screening might be performed to identify women with AFC > 5 and AMH > 1.1 ng/ml (Bologna criteria, AFC and AMH values are valid for one year).

Inclusion criteria for:

• Group 1: indication for oocyte cryopreservation
• Group 2: indication for IVF/ICSI and PGT-A

Inclusion criteria for both groups:

• First ovarian stimulation cycle
• Aged ≥ 18 and < 41 years old at the time of first OPU

Exclusion Criteria:

• contra-indication for ovarian stimulation
• expected poor ovarian response (Bologna Criteria)
• PCOS patients
• refusal to fill out questionnaires before, during and after treatment
• simultaneous participation in another clinical study
• untreated and uncontrolled thyroid dysfunction;
• current use of oral contraceptives, anti-psychotics, anti-epileptics or chemotherapy;
• pregnant or breastfeeding women. A woman is considered of childbearing potential (WOCBP), i.e. fertile, following menarche and until becoming postmenopausal unless permanently sterile. Permanent sterilization methods include hysterectomy, bilateral salpingectomy and bilateral oophorectomy. A postmenopausal state is defined as no menses for 12 months without an alternative medical cause.