P-28: The utility of serum leptin and follicular fluid leptin, estradiol, and progesterone concentrations in infertility patients undergoing in vitro fertilization

Abstract

Recently, serum leptin levels were demonstrated to fluctuate in a manner similar to other hormones of the female reproductive axis. The role and predictive value of serum and follicular fluid leptin and steroid hormone levels for in vitro fertilization (IVF) remains to be fully elucidated. Our objective was to prospectively asses the correlation and significance of serum leptin and follicular fluid leptin, estradiol, and progesterone with IVF outcomes. Prospective Cohort. Ten patients were enrolled during a single IVF cycle. Serum leptin levels were obtained at six different times during the IVF stimulation cycle and follicular fluid leptin, progesterone, and estradiol were obtained at the time of oocyte retrival. Follicular fluid levels of leptin, estradiol, and progesterone were measured via enzyme immunoassay. Serum leptin and estradiol levels both significantly increased for the individual patients during the IVF stimulation process (p < 0.05). None of the leptin levels differed based on pregnancy outcome. All leptin levels correlated significantly with other serum and follicular fluid leptin levels throughout the IVF cycle (p < 0.01). BMI significantly correlated with all leptin levels (p < 0.01). Follicular fluid leptin, estradiol, and progesterone levels did not correlate with each other, indicating independent regulation. Interestingly, follicular fluid estradiol levels correlated with serum estradiol levels only in patients with a positive pregnancy outcome (r = 0.97, p < 0.01) whereas serum and follicular fluid estradiol were unrelated in patients that did not achieve a successful pregnancy (r = 0.14, p = 0.81). No other correlations were found between serum or follicular fluid leptin levels and patient demographics, IVF pre-stimulation parameters, IVF stimulation parameters or IVF cycle outcomes. Leptin levels significantly increased during the IVF cycle and varied between patients based on BMI. Leptin levels seem to respond to gonadotropin stimulation but do not correlate with serum or follicular fluid hormone levels. Leptin follicular fluid levels are directly related to serum leptin levels. While we did not identify a dependency of pregnancy outcome on leptin, it appears that pregnancy outcome success may be reflected in the relationship between follicular fluid and serum levels of estradiol, independent of leptin levels.