IVM - Fresh ET (THE SAIGON PROTOCOL) Versus IVF - FET in PCOS Women

1. Screening for eligibility and randomization: Women who are potentially eligible are provided with information about the trial. Screening is done on the day of the first visit, and patients are given informed consent form to sign before enrollment. Participants are then randomly assigned (1:1) to either the CAPA-IVM or IVF-FET group. 2. After randomisation 2.1. IVM-FRESH (The SAIGON Protocol): * Treatment begins on day 2-4 of the menstrual cycle. * Endometrial preparation uses oral estradiol valerate (Progynova®; Delpharm Lille SAS, France) 8mg/day for at least 10 days. * Immature oocyte retrieval is performed when the endometrial thickness is ≥ 8 mm. * Mature oocytes are fertilized via ICSI. * Luteal phase support is provided with vaginal progesterone (800 mg/day) + dydrogesterone (20mg/day) starting on the day of ICSI. * A fresh embryo transfer is performed three or five days after progesterone administration, depending on the embryo stage. 2.2. IVF-FET (Frozen Transfer Protocol): * This protocol uses a random start approach, beginning on the day of the patient's first visit. * Ovarian stimulation is done using a GnRH antagonist protocol with a starting dose of 150 IU/day of rFSH. * A GnRH agonist trigger is administered when at least two leading follicles reach ≥ 17 mm in diameter. * Insemination is performed using ICSI for matured oocytes. * The endometrium is prepared for frozen embryo transfer using oral oestradiol valerate (8mg/day) and vaginal progesterone (800 mg/day) + dydrogesterone (20mg/day) when endometrial thickness is ≥ 8 mm. * Surviving embryos are thawed and transferred two hours after thawing under ultrasound guidance. 3. Pregnancy and outcomes: * A pregnancy test is performed 10-14 days after embryo transfer. A positive result is a serum hCG level of ≥ 25 mIU/mL. * Both groups continue hormone supplementation if the pregnancy test is positive. * The primary outcome of the study is the live birth rate after one embryo transfer. Secondary outcomes include cumulative ongoing pregnancy, time to ongoing pregnancy, clinical pregnancy rate, miscarriage, and other treatment and pregnancy complications. * Obstetric and neonatal outcomes: All data relating to the delivery process and neonatal care will be recorded by the data management system of IVFMD.