GnRH Agonist vs. hCG for Triggering of Ovulation – Differential Effects on Gene Expression in Human Granulosa Cells

OBJECTIVE To investigate the mRNA expression of genes related to steroidogenesis and OHSS in granulosa cells (GCs) of patients triggered with GnRH agonist compared to patients triggered with hCG. DESIGN Mural GCs were obtained at the time of oocyte retrieval and gene expression was analyzed using quantitative real time RT-PCR. SETTINGS Single center, case control study. PATIENT(S) 24 women who were treated with GnRH agonist or hCG for triggering of ovulation. INTERVENTIONS GC collection. MAIN OUTCOME MEASURE(S) The expression of genes related to steroidogenesis and OHSS in mural GCs. RESULTS The fertilization rate was similar in the two groups. The mRNA expression of CYP19A1 (0.50 vs 1, arbitrary unit), CYP11A1 (0.6 vs. 1) and 3 beta hydroxysteroid-dehydrogenase (0.39 vs 1) was significantly lower in the GnRH group. The expression of VEGF (0.74 vs. 1) and inhibin β B (0.38 vs 1) was lower in the GnRH analog triggered group. CONCLUSION Expression of genes related to steroidogenesis is lower at the time of oocyte retrieval in patients triggered with GnRH agonist. The decreased expression of VEGF and inhibin β B in the GnRH agonist group can explain the mechanism of early OHSS prevention.