Polycystic ovary syndrome (PCOS) is one of the most common gynaecological endocrine diseases in women and the main cause of anovulatory infertility. Compared with women with normal ovulation, PCOS patients are more likely to face ovarian hyperstimulation syndrome, poor-quality of oocyte and fertilization failure in assisted reproduction treatment, so ovulation induction in PCOS patients has attracted much attention in the reproductive field. Progestin-primed ovarian stimulation (PPOS) protocol uses exogenous progesterone effectively to block luteinizing hormone surge to achieve ideal number of retrieved oocytes, embryo quality and pregnancy outcomes. This article reviews the mechanism, clinical application and development of PPOS protocol in PCOS patients.

Polycystic ovary syndrome (PCOS) is one of the most common gynaecological endocrine diseases in women and the main cause of anovulatory infertility. Compared with women with normal ovulation, PCOS patients are more likely to face ovarian hyperstimulation syndrome, poor-quality of oocyte and fertilization failure in assisted reproduction treatment, so ovulation induction in PCOS patients has attracted much attention in the reproductive field. Progestin-primed ovarian stimulation (PPOS) protocol uses exogenous progesterone effectively to block luteinizing hormone surge to achieve ideal number of retrieved oocytes, embryo quality and pregnancy outcomes. This article reviews the mechanism, clinical application and development of PPOS protocol in PCOS patients.

A global expert consensus (the Delphi consensus) on follicular development, pituitary inhibition, triggering ovulation, and luteal phase support was organized and published in 2021 by Merck Darmstadt, Germany, to further complement the 2019 European Society of Human Reproduction and Embryology (ESHRE) Guidelines on Ovarian Stimulation by in vitro Fertilization (IVF)/Intracytoplasmic Sperm Injection(ICSI). Compared with the ESHRE guidelines, the Delphi consensus incorporates more types of research evidence and expert experience, and finally the expert group has reached a good consensus on follicular development, pituitary suppression and triggering of ovulation, but luteal support is still controversial. This article intends to provide a reference for the optimization of assisted reproductive technology through the interpretation of this consensus.

A global expert consensus (the Delphi consensus) on follicular development, pituitary inhibition, triggering ovulation, and luteal phase support was organized and published in 2021 by Merck Darmstadt, Germany, to further complement the 2019 European Society of Human Reproduction and Embryology (ESHRE) Guidelines on Ovarian Stimulation by in vitro Fertilization (IVF)/Intracytoplasmic Sperm Injection(ICSI). Compared with the ESHRE guidelines, the Delphi consensus incorporates more types of research evidence and expert experience, and finally the expert group has reached a good consensus on follicular development, pituitary suppression and triggering of ovulation, but luteal support is still controversial. This article intends to provide a reference for the optimization of assisted reproductive technology through the interpretation of this consensus.