Triggers in controlled ovarian hyperstimulation

Abstract

Controlled ovarian hyperstimulation (COH) is a crucial component of assisted reproductive technologies like intrauterine insemination (IUI) and in vitro fertilization (IVF). Triggers in COH play a pivotal role in maturation of the follicles in their final stages and optimizing the timing of egg retrieval, which is very important for the collection of maximum eggs and for a good success rate. Human chorionic gonadotropin (hCG) is used as a standard method for the final follicular maturation and ovulation. HCG has the similar effect as luteinizing hormone (LH) with a half-life of 5–7 days. Now a days, gonadotropin-releasing hormone agonist (GnRH-a) trigger has been used with the target to reduce OHSS for the induction of final follicular maturation and ovulation. Based on the results of various studies, using the GnRH-a trigger leads to defects in the luteal phase resulting in reduced implantation and clinical pregnancy rates and also increasing abortion rates in fresh embryo transfer cycles compared to the routine IVF cycle with hCG triggering. In this review, we examined the benefits, problems and also ways to reform various triggers used for ovulation.