Optimal usage of dual trigger to prevent OHSS in a long-protocol IVF cycle

Abstract

When a patient undergoing an long protocol IVF cycle has high risk of severe OHSS, rescuing the cycle by withdrawing the agonist, replacing (adding) it with an antagonist and triggering with a GnRH agonist has been considered. However, we underwent lower the number of oocytes retrieval in GnRH agonist trigger group. Therefore we aimed to compare outcomes between trigger with GnRH agonist and dual trigger (GnRH agonist and low dose hCG). In addition, optimal hCG dosage is investigated in dual trigger with combination of gonadotropin-releasing hormone agonist and human chorionic gonadotropin. A prospective clinical study. We evaluated total 26 high responder patients with a long protocol during 2009∼2013. We monitored by measuring the follicle number and serum E2 level on day 7 of the cycle. On the first day of monitoring, we observed that serum E2 was 500∼1500pg/mL and 10∼20 follicles were >10mm in each ovary. For these patients, we applied that agonist was interrupted and the antagonist (0.25mg/day) administrated 1-3 times (depending on a patients) until the day of hCG trigger. When at least two follicles had reached 18mm diameter, final follicular maturation was induced with GnRH agonist (Group I, n=7), dose of 1000 IU hCG and GnRH agonist (Group II, n=8) or 2000 IU hCG and GnRH agonist (Group III, n=10). The number of retrieved oocytes in Group I was significantly lower than those in Group II and Group III (4.7±1.5 vs. 10.0±3.7 vs. 20.2±6.8, p<0.01). The oocyte retrieval rate was the highest the Group III (p<0.01). However, no significant difference was observed in fertilization rate (66.7% vs. 67.5% vs. 61.4%) and cleavage rate (86.4% vs. 90.7% vs. 93.5%). Clinical pregnancy rate was significantly higher in group II (75.0%) and III (70.0%) than that in group I (14.3%, P<0.05) However, group II and III didn’t find significant differences. And there was 1 case of mild OHSS in the group III but none in the group II. For higher responders of a long protocol IVF cycle, dual trigger with a combination of GnRH agonist and low dose hCG (1000 IU) is induced the prevention of OHSS, successful high oocyte retrieval rate and ultimately increased pregnancy outcome.