Abstract: In assisted reproductive technology (ART), the trigger option is part of the individualized treatment. Based on the individual differences of patients, the choice of trigger scheme is very important. The optimal trigger scheme can improve the oocyte maturation rate and oocyte harvest rate without affecting fertilization, embryo development and euploidy rate, and reduce the incidence of ovarian hyperstimulation syndrome (OHSS). Currently, the most commonly used triggers in clinical practice are human chorionic gonadotropin (hCG) trigger and gonadotropin releasing hormone agonist (GnRHa) trigger, while the other triggers are rarely used. However, the only two schemes of hCG trigger and GnRHa trigger are insufficient to provide the individualized treatment for all of the patients. The advantages and controversies of different trigger schemes are reviewed in order to guide clinicians to provide the individualized trigger schemes for patients.

Key words: Reproductive techniques, assisted, Fertilization in vitro, Ovulation induction, Human chorionic gonadotropin, Gonadotropin releasing hormone agonist, Trigger