86 : Use of Triptorelin Versus Human Chorionic Gonadotropin as Ovulation Trigger

Background and Aims: Gonadotropin releasing hormone agonist (GnRH-a) trigger has been shown to be associated with significantly lower risk of moderate or severe ovarian hyperstimulation syndrome (OHSS) when compared among women at high risk of OHSS. However, trigger failure has been shown to occur in 2% of cycles using GnRH-a as trigger. This study aims to review the use of GnRH-a as ovulation trigger. Method: Retrospective review of records in antagonist cycles from an ART unit in a tertiary hospital from 2017-2021 was performed. Follicles were considered mature when they reach ≥ 15 mm. Ovulation triggered with urinary human chorionic gonadotropin (uhCG) (5000-10000 IU), recombinant hCG (rhCG) 250 mcg, or triptorelin 0.2 mg when there were ≥ 3 mature follicles. All embryos obtained from cycles using triptorelin were cryopreserved. Outcome including the number of oocytes retrieved, the follicle to oocyte index, ovarian hyperstimulation syndrome were reviewed. Results: 1378 cycles were included. 1089 cycles had uhCG or rhCG as trigger, while 284 cycles had triptorelin as trigger. Women in the triptorelin group were significantly younger with a lower basal follicle stimulating hormone level and a higher antral follicle count (Table 1). In the triptorelin group, the total number of mature sized follicles, estrogen level at trigger, oocytes retrieved, number of blastocysts were significantly higher compared to the hCG group (Table 2). Follicle to oocyte index was significantly higher in the triptorelin group but the proportion of mature oocytes were similar in both groups. There were no cases of trigger failure and OHSS in the triptorelin group, but 30 cases of OHSS, with18 cases early onset, 12 cases late onset, amongst them 10 cases (1%) were severe OHSS) in the hCG group. Conclusion: GnRH-a trigger is a good candidate as ovulatory trigger in women at risk of OHSS without hampering the laboratory outcome.