GnRH Antagonist in Ovarian Stimulation

In this chapter, we discuss the introduction of GnRH antagonists into IVF, their mechanism of action and how they differ from GnRH agonist use in IVF. The chapter discusses the dosing of GnRH antagonists: single versus multiple dose protocols, timing of commencement: fixed versus flexible start protocols and their efficacy. We finally discuss the role of GnRH antagonist in individualized controlled ovarian stimulation (COS) protocols, its reduction of the risk of ovarian hyperstimulation syndrome (OHSS) and it enabling the use of the GnRH agonist trigger with potential elimination of OHSS.