GnRH agonist versus HCG triggering in different IVF/ICSI cycles of same patients: a retrospective study

The aim of this study was to assess Gonadotropin Releasing Hormone agonist (GnRHa) trigger results of fresh in vitro fertilisation (IVF), Intracytoplasmic Sperm Injection (ICSI) cycles in high-responder patients. Thirty-six high-responder patients, undergoing GnRH antagonist protocol combined with GnRHa trigger for final oocyte maturation, were included. All cycles were autologous fresh transfer cycles. Fifteen of 36 patients had previous IVF/ICSI cycles triggered with human chorionic gonadotropin (hCG) and both cycles of these patients were compared. The mean fertilisation rate, blastocyst development and clinical pregnancy rates were 67%, 44.4% and 44.4%, respectively. The hCG and GnRHa trigger cycles of the same patients were compared as two groups (n: 15). 2PN oocyte counts were significantly higher in agonist trigger cycles (p .048). There were no differences in terms of M2 oocyte count and fertilisation rate. The blastocyst formation and clinical pregnancy rates for hCG and GnRHa trigger cycles were 33.3-66.7% and 13.3-46.7%, respectively. These results were found to be 2-fold and 3.5-fold higher, but not statistically significant. GnRHa trigger in combination with LPS is a good option for final oocyte maturation due to its good pregnancy outcomes and virtually eliminating OHSS risks.IMPACT STATEMENTWhat is already known on this subject? Gonadotrophin releasing hormone agonist (GnRHa) trigger is effective in the induction of oocyte maturation and prevention of Ovarian Hyperstimulation Syndrome (OHSS) on IVF cycles using antagonist protocol.What do the results of this study add? The main strength of this study is the comparison of different triggers in different cycles of the same patients. GnRHa trigger in combination with Luteal Phase Support (LPS) is a good option for final oocyte maturation due to its good pregnancy outcomes and virtually eliminating OHSS risks.What are the implications of these findings for clinical practice and/or further research? We suppose that GnRHa trigger combined with modified LPS is clinically more successful than Human Chorionic Gonadotropin (hCG) in regard to OHSS prevention and reproductive outcomes on fresh IVF/ICSI cycles. More extensive studies are needed to draw firm conclusions.