Is PPOS Better Than GnRH Antagonists for IVF Cycles?

Benefits of Progestogen-Primed Ovarian Stimulation

Modern fertility treatments require a safe and highly effective ovarian stimulation protocol. Consequently, clinicians constantly seek options that reduce cost and patient discomfort. In July 2026, researchers published a landmark systematic review. This paper compared progestogen-primed ovarian stimulation (PPOS) with traditional gonadotropin-releasing hormone (GnRH) analogs. This comprehensive analysis evaluates the outcomes of 4,430 participants across 20 randomized controlled trials.

The systematic review shows promising results for women undergoing assisted reproduction when fresh-embryo transfer is not intended. Specifically, the authors compared PPOS against GnRH antagonists in 17 trials. The analysis demonstrates that PPOS significantly improves the overall live-birth rate. Additionally, patients using this oral regimen achieved a higher number of retrieved oocytes compared to those on GnRH antagonist protocols.

Improving IVF Outcomes with the Ovarian Stimulation Protocol

The selection of an appropriate ovarian stimulation protocol directly influences the success of in-vitro fertilization (IVF). In this meta-analysis, PPOS demonstrated a relative risk (RR) of 1.13 for live-birth rates compared to GnRH antagonists. Moreover, this finding remained robust during strict sensitivity analyses. Clinicians retrieved an average of 0.88 more oocytes per cycle with the PPOS protocol. Therefore, this method offers a clear clinical advantage for freeze-all cycles.

Safety remains a paramount concern for any reproductive specialist. Fortunately, the analyzed cohorts reported no cases of moderate or severe ovarian hyperstimulation syndrome (OHSS). Furthermore, the rates of premature luteinizing hormone (LH) surges and oocyte pick-up cancellations did not differ significantly between the groups. Thus, PPOS presents a remarkably safe and reliable alternative to conventional injectable regimens.

Comparing Alternative Regimens and Clinical Feasibility

Besides GnRH antagonists, the review also analyzed PPOS against GnRH agonists. However, the data revealed no significant differences in live-birth rates or retrieved oocytes between these two groups. Similarly, a combined GnRH agonist and antagonist regimen showed equivalent efficacy. Because PPOS utilizes oral administration and costs significantly less, it offers unmatched feasibility for patients. As a result, many clinics may transition to this patient-friendly approach.

Frequently Asked Questions

Q1: What is progestogen-primed ovarian stimulation (PPOS)?

PPOS is an alternative ovarian stimulation protocol that uses oral progestogens instead of injectable GnRH analogs to prevent a premature luteinizing hormone surge during in-vitro fertilization.

Q2: Why is PPOS considered a good alternative for IVF patients?

According to clinical evidence, PPOS achieves higher live-birth rates and yields more oocytes than GnRH antagonists. Additionally, its oral administration significantly lowers treatment costs and improves patient comfort.

References

1. Martins WP et al. Progestogen-primed ovarian stimulation vs GnRH antagonists and/or agonists for women undergoing assisted reproduction: systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2026 Jul 09. doi: 10.1002/uog.70267. PMID: 42425545.
2. Ata B, Kalafat E. Progestin-primed ovarian stimulation: for whom, when and how? Reprod Biomed Online. 2024 Mar;48(2):103639. doi: 10.1016/j.rbmo.2023.103639.
3. Wang L et al. Progestin-Primed Ovarian Stimulation Protocol for Patients in Assisted Reproductive Technology: A Meta-Analysis of Randomized Controlled Trials. Front Endocrinol. 2021 Aug 31;12:702558. doi: 10.3389/fendo.2021.702558.