We aimed to characterize the association between levels of serum and follicular fluid (FF) adipocytokines, reflected by the leptin to adiponectin ratio (L:A ratio), and oocyte quality and in vitro embryo development in women undergoing assisted reproduction. We also aimed to assess whether follicular hormonal pathways mediate this interaction.
We prospectively collected FF from up to four individual preovulatory follicles (n = 76) and fasting sera from women (n = 31) without endocrinopathies undergoing in vitro fertilization (IVF) at a university-based center for assisted reproduction. Leptin, total adiponectin, insulin, insulin-like growth factor 1 (IGF-1), and ovarian steriods were measured using enzyme immunoassay. Oocyte maturity, fertilization, and embryo development were assessed.
FF leptin was similar to serum levels while FF adiponectin was lower. FF leptin (27.10 ± 4.05 ng/mL) and the L:A ratio (11.48E−3 ± 2.57E−3) were related to FF insulin (R2 = 0.370 and 0.419, p < 0.001) but not to ovarian steroids or IGF-1, whereas FF adiponectin ( 4.22 ± 0.52 ug/mL) correlated only with leptin (R2 = −0.138, p = 0.001). Oocytes from a high FF L:A ratio environment were 81 % (RR 1.81 [95%CI 0.97–3.37]) more likely to undergo successful cleavage and 117 % (RR 2.17 [95 % CI 1.06–4.44]) more likely to obtain viable cleavage morphology compared to a low FF L:A ratio environment, even when adjusted for FF insulin, an independent predictor of cleavage.
Certain adipocytokines, particularly the L:A ratio in the FF of the preovulatory follicle, are related to successful in vitro embryo development. This action may be independent of FF insulin.