This is a prospective, randomized, single center, phase 4 controlled trial. The study will compare the efficacy of two different strategies for the management of predicted poor response patients under stimulation for IVF/ICSI: up to three MNC cycles (group 1) versus a single GnRH antagonist CFA (group 2).

Inclusion Criteria:

• Informed consent form (ICF) dated and signed.
• Age ≥18 and <45 years old.
• Body Mass Index (BMI) ≥18.5 Kg/m² and <35 Kg/m².
• Regular menstrual cycles (between 21 and 35 days).
• Two ovaries present.
• Current pregnancy wish.
• Poor responders as defined according to the POSEIDON criteria:

POSEIDON Group 3: patients < 35 years with poor ovarian reserve pre-stimulation parameters (AFC <5 or AMH <1.2 ng/mL); POSEIDON Group 4: patients ≥35 years with poor ovarian reserve pre-stimulation parameters (AFC <5 or AMH <1.2 ng/mL).

Exclusion Criteria:

• Simultaneous participation in another clinical study.
• Untreated and uncontrolled thyroid dysfunction.
• Tumors of the ovary, breast, uterus, pituitary or hypothalamus.
• Abnormal (not menstrual) vaginal bleeding without a known/diagnosed cause.
• Ovarian cysts or enlarged ovaries.
• Malformations of the reproductive organs.
• Current use of oral contraceptives, anti-psychotics, anti-epileptics or chemotherapy.
• Previous antibiotic hypersensitivity reactions (streptomycin and/or neomycin).
• Patients who undergo preimplantation genetic testing (PGT), fertility preservation or oocyte donation.