Progestin-Primed Ovarian Stimulation in Assisted Reproductive Technology
Summary
Progestin-primed ovarian stimulation (PPOS) is a controlled ovarian hyperstimulation strategy that employs oral progestin from the early follicular phase in combination with exogenous gonadotrophins to prevent a premature luteinising hormone (LH) surge. By synchronising follicular development and suppressing endogenous LH, this protocol enables flexible timing of oocyte retrieval and shifts embryo transfers to frozen-thawed cycles. Compared with conventional gonadotrophin releasing hormone (GnRH) antagonist or agonist approaches, PPOS offers the advantages of an oral administration route, reduced injection burden and potentially lower risk of ovarian hyperstimulation syndrome. Clinical applications encompass women with normal ovarian reserve, polycystic ovary syndrome (PCOS) and diminished ovarian reserve. Recent investigations have focused on cumulative live birth rates across multiple frozen-thawed embryo transfer cycles, the impact on oocyte and blastocyst quality, and age-related effects on embryo chromosomal integrity. Ongoing research seeks to optimise progestin dosage regimens, refine patient selection criteria and elucidate the molecular mechanisms by which progestin modulates folliculogenesis and endometrial receptivity.
Research from Nature Portfolio
Recent studies have compared medroxyprogesterone acetate–based protocols with GnRH antagonist regimens for the prevention of premature LH surge during controlled ovarian stimulation. In a large retrospective analysis of more than 1 500 cycles conducted between 2018 and 2022, oral medroxyprogesterone acetate demonstrated equivalent efficacy to antagonist protocols in preventing premature ovulation, while yielding comparable numbers of retrieved oocytes, embryo development and clinical pregnancy rates. These findings support the use of progestin as a practical alternative to injectable antagonists in centres where fresh embryo transfer is not planned, offering similar reproductive outcomes with reduced patient discomfort.
Progestin-Primed Ovarian Stimulation in Assisted Reproductive Technology publication trend
The graph below shows the total number of articles in progestin-primed ovarian stimulation in assisted reproductive technology across all publications each year (not limited to Nature Index journals).
Technical terms
Progestin-Primed Ovarian Stimulation (PPOS): A stimulation protocol using exogenous progestin from the start of the cycle to suppress LH surges during follicular development.
Gonadotrophin Releasing Hormone (GnRH) Antagonist: A medication that directly inhibits GnRH receptors in the pituitary to prevent premature LH release.
Luteinising Hormone (LH) Surge: The endogenous hormonal peak that triggers final oocyte maturation and ovulation.
Antral Follicle Count (AFC): The ultrasound-determined number of small ovarian follicles at baseline, serving as a marker of ovarian reserve.
Euploidy Rate: The proportion of embryos with the correct chromosomal complement as determined by genetic screening.
Frozen-Thawed Embryo Transfer (FET): The process of transferring embryos that have been cryopreserved and subsequently thawed in a later cycle.
References
- The cumulative live birth rates of 18 593 women with progestin-primed ovarian stimulation-related protocols and frozen-thawed transfer cycles. Human Reproduction Open (2023).
- Progestin Primed Ovarian Stimulation (PPOS) protocol yields lower euploidy rate in older patients undergoing IVF. Reproductive Biology and Endocrinology (2023).
- Comparison of cumulative live birth rates between progestin-primed ovarian stimulation protocol and gonadotropin-releasing hormone antagonist protocol in different populations. Frontiers in Endocrinology (2023).
- In vitro fertilization results of GNRH antagonists and medroxyprogesterone acetate used to prevent premature LH surge during ovarian hyperstimulation. Scientific Reports (2024).
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