The goal of this clinical trial is to compare two ovarian stimulation protocols used in in vitro fertilization (IVF): the fixed Progestin-Primed Ovarian Stimulation (PPOS) protocol and the GnRH Antagonist protocol. The study will evaluate IVF outcomes and embryo development patterns using time-lapse embryo monitoring technology. The main questions the study aims to answer are:

• Does the fixed - PPOS protocol achieve similar numbers of mature eggs, good-quality embryos, and clinical outcomes compared to the GnRH Antagonist protocol?
• Are there differences in embryo development patterns (morphokinetics) between the two protocols when monitored by time-lapse imaging?
• How does embryo quality (KIDScore) compare between the two protocols?

Study Design:

Researchers will randomly assign 148 women undergoing IVF to two groups:

• PPOS group (n=74): Will receive FSH injections (oral Duphaston 20mg daily) starting from day 2-3 of the menstrual cycle
• GnRH Antagonist group (n=74): Will receive FSH injections (Orgalutran 0.25mg injections) when follicles reach ≥14mm

Participants will:

• Undergo controlled ovarian stimulation with their assigned protocol for approximately 10-12 days
• Have regular ultrasound monitoring and blood tests to track follicle development
• Undergo egg retrieval procedure when follicles are mature
• Have all embryos cultured in the EmbryoScope time-lapse incubator with continuous monitoring
• Have embryos frozen on Day 5/6 for future transfer

Study Location:

Department of Assisted Reproduction and Andrology, Hanoi Obstetrics and Gynecology Hospital

Study Duration: January 2026 - June 2028

Inclusion Criteria:

• Women aged 20-45 years
• Indicated for in vitro fertilization (IVF) treatment
• Planned freeze-all embryo strategy
• Voluntary participation in research.

Exclusion Criteria:

• Systemic diseases
• Use of hormonal medications within 3 months prior to enrollment
• Oocyte donation cycles
• Unwilling or unable to participate in research

female