Difference Between Progestin Primed Ovarian Stimulation Protocol and Antagonist Protocol

Infertility treatments have evolved significantly over the past few decades, with various protocols being developed to optimize ovarian stimulation in assisted reproductive technology (ART). Among these protocols, the progestin-primed ovarian stimulation (PPOS) and the antagonist protocols have gained prominence, especially in hyper-responders who are scheduled for a freeze-all policy. Hyper-responders are patients who produce an excessive number of eggs in response to ovarian stimulation, which increases the risk of ovarian hyperstimulation syndrome (OHSS), a potentially severe complication .

The PPOS protocol involves the administration of progestins to suppress the premature luteinizing hormone (LH) surge during ovarian stimulation, thereby providing a controlled environment for follicle development. This method has been found to be effective in reducing the risk of OHSS and improving clinical outcomes . On the other hand, the antagonist protocol employs gonadotropin-releasing hormone (GnRH) antagonists to prevent the LH surge, offering a more immediate suppression compared to progestins .

A freeze-all policy, where all viable embryos are frozen for future use rather than being transferred immediately, is often recommended for hyper-responders to further minimize the risk of OHSS . This approach allows for the transfer of embryos in a more physiologically normal uterine environment, potentially improving implantation rates and pregnancy outcomes .

This study aims to compare the effectiveness and safety of the PPOS protocol versus the antagonist protocol in hyper-responder patients scheduled for a freeze-all policy. By examining outcomes such as the number of retrieved oocytes, incidence of OHSS, and pregnancy rates, this research seeks to provide insights into the optimal ovarian stimulation strategy for this specific patient population.