Retrospective comparison of GnRH agonist trigger with HCG trigger in GnRH antagonist cycles in anticipated high-responders

•GnRH-agonist ovulation trigger followed by a single low dose of hCG in the luteal phase resulted in good live-birth/ongoing pregnancy rates when compared with hCG trigger for anticipated high-responders.•There was a non-significantly lower incidence of mild-moderate OHSS and no cases of severe OHSS with the use of GnRH-agonist trigger in 62 women who were suspected to be at risk of OHSS on initial assessment.•Compared with hCG trigger, GnRH-agonist may reduce the need for freezing all embryos and thereby improve the IVF treatment outcomes per started cycles.

All IVF-ICSI cycles carried out between October 2009 and October 2012 using GnRH agonist (GnRHa) ovulation trigger (n = 62) followed by a single dose of HCG plus progesterone and oestradiol in the luteal phase because of anticipated ovarian hypertsimulation were retrospectively compared with historic control cycles using HCG trigger (n = 29) and standard luteal phase support. Women's mean age, body mass index, anti-Müllerian hormone, FSH, LH, starting and total stimulation dose, number of follicles, oocytes, embryos, fertilization, implantation, polycystic ovary syndrome, ICSI, live birth and ongoing pregnancy rates per embryo transfer were similar (GnRHa 40.7% versus HCG 35.0%). For each started cycle, GnRHa resulted in 11.4% higher (statistically non-significant) live birth and ongoing pregnancy rate (OR 1.73, CI 0.64 to 4.69), with a similar difference for double-embryo transfers (OR 1.62, CI 0.44 to 6.38) and less need for freezing all embryos (9.7% versus 27.6%; P = 0.04). Incidence of mild-to-moderate OHSS was 16.2% with GnRHa trigger and 31.0% with HCG trigger) and no severe OHSS in the former. The addition of single low-dose HCG in the luteal phase after GnRHa trigger for suspected high-responders reduced the incidence of OHSS with good clinical outcomes, compared with HCG trigger.