Controlled ovarian stimulation was performed according the clinical protocol as previously described and according to the specific clinical requirements of the patients [21 (link)]. Briefly, on the second to third day of menstruation, ovarian stimulation was initiated with synthetic follicle-stimulating hormone (FSH) alone (Gonal-F, Merck-Serono, Italy; or Bravelle, Ferring Pharmaceutical, Germany) or FSH and luteinizing hormone (LH) (Pergoveris, Merck-Serono, Italy; or Menopur, Ferring Pharmaceutical, Germany) treatments. FSH dosages varied from 150 to 300 IU/day, and LH dosages ranged from 75 to 300 IU/day. The gonadotropin-releasing hormone antagonist cetrorelix acetate (Cetrotide 0.25 mg, Merck-Serono, Italy) was administered to induce hypophysis suppression whenever the first follicle was ≥14 mm.
When at least one follicle had reached 18 mm or at least 2 follicles had reached 16 mm (assessed by ultrasound), human chorionic gonadotropin (hCG) (Ovidrel 250 μg, Merck-Serono, Italy) was administered to mimic the LH peak. Thirty-five hours post-Ovidrel administration, the oocytes were retrieved, and FF was obtained during the follicular aspiration procedure.
When at least one follicle had reached 18 mm or at least 2 follicles had reached 16 mm (assessed by ultrasound), human chorionic gonadotropin (hCG) (Ovidrel 250 μg, Merck-Serono, Italy) was administered to mimic the LH peak. Thirty-five hours post-Ovidrel administration, the oocytes were retrieved, and FF was obtained during the follicular aspiration procedure.