Associations between free fatty acids, cumulus oocyte complex morphology and ovarian function during in vitro fertilization

OBJECTIVE: To determine if follicular free fatty acid (FFA) levels are associated with cumulus oocyte complex (COC) morphology. DESIGN: Prospective cohort study. SETTING: University in vitro fertilization (IVF) practice. PATIENT(S): A total of 102 women undergoing IVF. INTERVENTION(S): Measurement of FFAs in serum and ovarian follicular fluid. MAIN OUTCOME MEASURE(S): Total and specific follicular and serum FFA levels, correlations between follicular and serum FFAs, and associations between follicular FFA levels and markers of oocyte quality, including COC morphology. RESULT(S): Predominant follicular fluid and serum FFAs were oleic, palmitic, linoleic, and stearic acids. Correlations between follicular and serum FFA concentrations were weak (r=0.252, 0.288, 0.236, 0.309, respectively for specific FFAs; r=0.212 for total FFAs). A receiver operating characteristic curve determined total follicular FFAs≥0.232 μmol/mL distinguished women with a lower versus higher percentage of COCs with favorable morphology. Women with elevated follicular FFAs (n=31) were more likely to have COCs with poor morphology than others (n=71; OR 3.3, 95% CI1.2-9.2). This relationship held after adjusting for potential confounders, including age, body mass index, endometriosis, and amount of gonadotropin administered (β=1.2; OR 3.4, 95% CI 1.1-10.4). CONCLUSION(S): Elevated follicular FFA levels are associated with poor COC morphology. Further work is needed to determine what factors influence follicular FFA levels and if these factors impact fertility.