Endometrioma may differentially affect eicosanoids in the follicular fluid and serum of infertile women with endometriosis

OBJECTIVE: The etiopathogenesis of endometriosis-related infertility remains under investigation, including in women with endometriomas. Oocyte quality is believed to play an important role in the impairment of natural fertility in these patients, with systemic inflammation and oxidative stress acting as mediators of oocyte damage. Eicosanoids are bioactive lipids produced in response to inflammatory or oxidative conditions and are involved in various ovarian processes; their dysregulation may impair oocyte competence. This study aimed to compare the serum and follicular fluid eicosanoid profiles of women with and without endometriosis, including women with and without endometrioma. METHODS: In this prospective cohort study, blood and follicular fluid samples were collected on the day of oocyte retrieval from 18 infertile women with endometriosis (8 with endometrioma and 10 without endometrioma) and 20 patients with tubal and/or male-factor infertility. The eicosanoid profiles of the samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: No differences were found in serum eicosanoids between the endometriosis and control groups. After subdividing the endometriosis group into women with and without endometrioma, we observed lower serum levels of 5-hydroxyeicosatetraenoic acid (5-HETE) in those with endometrioma (38.47pg/mL vs. 120.45pg/mL; p=0.01). Increased follicular levels of eicosapentaenoic acid (EPA) were found in women with endometriosis (4038.52pg/mL; p=0.03) and in those with endometrioma (5811.50pg/mL; p=0.005) compared with controls (1159.83 pg/mL). CONCLUSION: The findings suggest that pelvic disease promotes a systemic pro-inflammatory alteration, whereas endometrioma induces a local anti-inflammatory response. This may represent a mechanism to prevent oocyte damage, highlighting different mechanisms underlying endometriosis-related infertility according to lesion type. Further studies should confirm these findings using appropriate sample sizes and methodology.