Clinical Pregnancy and Incidence of Ovarian Hyperstimulation Syndrome in High Ovarian Responders Receiving Different Doses of hCG Supplementation in a GnRH-Agonist Trigger Protocol

OBJECTIVE: Ovarian hyperstimulation syndrome (OHSS) is a side effect of the exogenous human chorionic gonadotropin (hCG) hormones used to trigger oocyte maturation. High ovarian responders represent a population with a higher risk of OHSS and are characterized by an exaggerated response to gonadotropin administration. In this study, we compared clinical pregnancy and incidence of OHSS in high ovarian responders receiving different doses of hCG supplementation in a GnRH-agonist trigger protocol. METHODS: A total of 205 high ovarian responders who were to undergo in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles were recruited and randomly assigned to receive different doses of hCG supplementation in a GnRH-agonist trigger protocol: GnRH-a (n = 42), GnRH-a + 1000 IU hCG (n = 49), GnRH-a + 2000 IU hCG (n = 54), and GnRH-a + 3000 IU hCG (n = 60) groups. RESULTS: The GnRH-a + 1000 IU hCG, GnRH-a + 2000 IU hCG, and GnRH-a + 3000 IU hCG groups had more oocytes retrieved, embryos, high-quality embryos, and a higher rate of high-quality embryos than the GnRH-a group (p < 0.05). The GnRH-a + 1000 IU hCG group demonstrated more oocytes retrieved, embryos, high-quality embryos, and a higher rate of high-quality embryos than the GnRH-a + 2000 IU hCG and GnRH-a + 3000 IU hCG groups (p < 0.05). No moderate and severe OHSS cases occurred in the GnRH-a and GnRH-a + 1000 IU hCG groups. The incidence rate of moderate and severe OHSS was remarkably lower in the GnRH-a group and GnRH-a + 1000 IU hCG groups than in the GnRH-a + 2000 IU hCG and GnRH-a + 3000 IU hCG groups (p < 0.05). The GnRH-a + 1000 IU hCG, GnRH-a + 2000 IU hCG, and GnRH-a + 3000 IU hCG groups had a higher clinical pregnancy rate than the GnRH-a group, showing no significant difference (p > 0.05). The GnRH-a + 1000 IU hCG, GnRH-a + 2000 IU hCG, and GnRH-a + 3000 IU hCG groups had a lower abortion rate than the GnRH-a group (p < 0.05). CONCLUSION: Based on the data obtained from this prospective study, we recommend 1000 IU hCG supplementation in a GnRH-agonist trigger protocol for high ovarian responders during IVF/ICSI cycles considering a higher rate of high-quality embryos, a lower incidence rate of moderate and severe OHSS, and a lower abortion rate.