Controlled ovarian stimulation and triggers in in vitro fertilization: protocol personalization key to optimize outcomes

The past four decades have delivered many advancements to improve in vitro fertilization (IVF) outcomes. These include a delicate balance of controlled ovarian hyperstimulation (COH) without causing ovarian hyperstimulation syndrome (OHSS), a safe oocyte retrieval, fertilization and embryo culture, endometrial growth and receptivity to promote implantation, and luteal support to maintain the pregnancy. Contemporary IVF practice includes both the classic COH protocols as well as protocols for poor responders and those for specific patient populations. An assortment of agents have been developed and utilized in various combinations to improve COH outcomes and promote oocyte maturation while decreasing the risk of OHSS. Various protocols have evolved over time. Ideal practices involve selecting the optimal protocol for a personalized, patient-specific stimulation and trigger.