GnRH antagonist protocol with hCG triggering ameliorates fertilization defect caused by failure of cumulus cell pentraxin-3 expression in unilateral endometriomas.

Objective: The aim of the study was to determine the expression pattern of long pentraxin 3 (PTX3) mRNA in cumulus cells (CCs) isolated from metaphase II oocytes of women with unilateral endometrioma undergoing controlled ovarian stimulation using a gonadotropin-releasing hormone antagonist (GnRHa) protocol.

Patients and methods: A total of 60 CC samples, 30 from the affected ovary and 30 from the contralateral ovary, were collected from 12 patients with unilateral endometrioma who underwent flexible GnRHa protocol with recombinant human chorionic gonadotropin (rhCG) trigger. Thirty CC samples collected from the left ovary of 12 women with male factor infertility were used as external controls. Long PTX3 mRNA expression in each group was analyzed by real-time polymerase chain reaction (RT-PCR). Relative gene expression (fold-change) was calculated according to the 2-ΔΔCt equation. Fertilization rates after intracytoplasmic sperm injection (ICSI) were recorded for each group.

Results: CC-PTX3 mRNA expression in the unilateral endometrioma group was significantly lower than the mRNA expression of the disease-free ovary (0.90±0.01 vs. 0.25±0.02, p<0.01). CC-PTX3 mRNA expression of MII oocytes of the disease-free ovary was found to be similar to the control group (1.02±0.03 vs. 0.90±0.01, p=0.107). A significant 3.6-fold downregulation was observed in the CC-PTX3 mRNA expression of the endometrioma group compared to the CC-PTX3 mRNA expression in the contralateral ovary. CC-PTX3 mRNA expression in the endometrioma group was downregulated 4.08-fold compared to the CC-PTX3 mRNA expression of the control group (1.02±0.03 vs. 0.25±0.02, p<0.001). The cumulus morphologies of the endometrioma group with low CC-PTX3 expression and the groups with normal CC-PTX3 levels were similar. Fertilization rates of the endometrioma group were similar to the contralateral ovary and control groups.

Conclusions: Unilateral endometrioma reduces CC-PTX3 expression but does not affect disease-free ovaries. The GnRHa protocol improved the fertilization rates, suggesting that failed CC-PTX3 expression is an in vivo pathology.