Serum and follicular fluid ghrelin levels negatively reflect human oocyte quality and in vitro embryo development

ObjectiveTo characterize serum and follicular fluid (FF) ghrelin in women undergoing assisted reproduction and to evaluate ghrelin’s impact on ovarian steroidogenesis, oocyte quality, and embryo development.DesignProspective cohort study.SettingUniversity-based center for assisted reproduction.Patient(s)Normal weight women (n = 31) without endocrinopathies undergoing IVF.Intervention(s)Fasting serum and FF from individual preovulatory follicles (n = 81) were collected.Main Outcome Measure(s)Ghrelin, insulin, ovarian steroids, and IVF outcomes including oocyte maturity and embryo development were assessed.Result(s)The FF ghrelin correlated highly with serum levels and was 13% (3%–24%) lower. Levels were not associated with body mass or exogenous gonadotropins. Serum ghrelin correlated negatively with the cleavage rate and number of viable day 3 embryos. Embryos with successful cleavage and viable morphology came from follicles with lower ghrelin—odds ratios were 3.67 (1.02–13.14) and 3.46 (1.01–11.81), respectively. The FF ghrelin correlated negatively with FF insulin and progesterone, and positively with estradiol. The FF insulin was more than 50% higher (Δ = 1.88 [0.31–3.45] uIU/mL) in follicles with successfully cleaved embryos.Conclusion(s)The FF ghrelin does not reflect ovarian production and likely represents transudation. Ghrelin in FF correlates with local steroidogenesis and FF insulin expression. Serum and FF ghrelin are reflective of embryo development, possibly through interactions with FF insulin.