Abstract: In IVF/ICSI cycle, GnRH antagonist (GnRHA) is widely used with the advantages of the short time of Gn stimulation, the low cost, the flexible solutions, which is easily accepted by patients. Human chorionic gonadotropin (hCG) is usually used to lead follicle final maturity and discharge (also called hCG trigger). Compared with the luteinizing hormone (LH), hCG has similar effect in follicle final maturity and discharge, and long half-time. However, the risk of ovarian hyperstimulation syndrome (OHSS) of hCG trigger is increased due to its long luteinization effect. However, gonadotropin-releasing hormone agonist (GnRHa) can not only promote follicle maturation and ovulation (also called GnRHa trigger) at the same time, but also reduce the incidence of OHSS. The present studies showed that GnRHa trigger could eventually lead to the defects of luteal function and influence the clinical pregnancy rate, and increase fresh embryo abortion. There is an inconclusion on what kind of the luteal support protocols after GnRHa trigger, to eliminate the concerns in the fresh embryo transfer. The advantages and disadvantages of GnRHa trigger in IVF/ICSI cycles were discussed in this article.

Key words: Fertilization in vitro, Sperm injections, intracytoplasmic, Corpus luteum maintenance, GnRHa trigger, hCG trigger