Gonadotropin Releasing Hormone Agonist (GnRH-ag) Triggering in in-vitro Maturation (IVM) Cycles: New Insights into Physiology

Introduction :

hCG has been the traditional triggering of ovulation mode. Recently, hCG triggering is challenged and is often replaced by GnRH-ag. There is a lack of information regarding the use of GnRH agonist in the IVM practice.

Aim:

To evaluate the outcome of GnRH-ag triggering in IVM cycles

Materials and methods:

a retrospective cohort analysis of 60 IVM cycles between 2015-2017 comparing cycle outcome by mode of triggering. Indications for treatment were a pure ovulatory disorder, a mixed indication including an ovulatory component and oncological patients performing fertility preservation.

Results

A total of 60 IVM cycles were included, 20 of them triggered by GnRH agonist (S.C decapeptyl 0.3 mg) and 40 triggered by recombinant hCG (S.C. 250 micrograms). Means and P values are presented hereby for the GnRH-ag triggering group and HCG group, respectively: total number of eggs retrieved 9.7, 10.4 (P value 0.6), MII egg ratio on the day of retrieval 0.25,0.14 (P value 0.02), final MII egg ratio 0.53, 0.59 (P value 0.4) and fertilization rate of injected ova :0.8, 0.6 (P value 0.01). In a sub-analysis comparing only patients who were not exposed to gonadotropins (14 patients in the GnRH-ag group, 9 in the hCG group), both retrieval day MII ratio and fertilization rate showed a significant benefit to the GnRH-ag triggering.

Conclusions:

In IVM cycles, GnRH-ag triggering shows a significantly higher rate of metaphase II (MII) eggs on the day of retrieval and a significantly higher fertilization rate.