Progestin primed ovarian stimulation—a new stimulation regimens

Abstract

With the improvements of freezing embryos techiques for assisted reproductive technology (ART), freezing all the embryos after controlled ovarian hyperstimulation (COH) is realized. Thanks to the freeze-all policy, progesterone is actually used as part of the protocol, which we called the progestin primed ovarian stimulation (PPOS). The physiological principles of PPOS are the use of progesterone to block the luteinizing hormone (LH) surge and waves of folliculogenesis during the menstrual cycle. There are two ways of using progesterone, whether it be endogenous, as in luteal phase, or exogenous, as in the follicular phase. These two methods and a variety of stimulation protocols derived from them have already been proved that they do not affect the number of oocytes collected or the quality of the embryos obtained both in normal responders and poor responders, while being effective in blocking the LH surge. However, their medical and economic significance remains to be demonstrated. This paper makes a review of the progress of this new ovarian stimulation protocol here. Key words: Freeze-all policy; In vitro fertilization-embryo transfer (IVF-ET); Controlled ovarian hyperstimulation (COH); Luteal phase stimulation; Progestin primed ovarian stimulation (PPOS)