Ovarian Stimulation Effects on Ghrelin Secretion and Reproductive Potential

Area of Science:

• Reproductive Endocrinology
• Immunology
• Assisted Reproductive Technology

Background:

• Ghrelin (Ghrl) secretion requires precise regulation during early pregnancy.
• Elevated ghrelin levels can negatively affect fertility.
• Oestrogens stimulate ghrelin synthesis, potentially increasing ghrelinemia during ovarian stimulation (OS).

Purpose of the Study:

• To investigate if ovarian stimulation (OS) elevates ghrelinemia in women undergoing assisted reproduction.
• To assess the association between OS-induced ghrelinemia, maternal endocrine and immune biomarkers, and reproductive success.

Main Methods:

• A cohort of 97 women undergoing assisted reproduction was divided into three groups: OS (fresh embryo transfer), FET (frozen embryo transfer), and OD (oocyte donation).
• Serum levels of estradiol, progesterone, and ghrelin (Ghrl) were measured on the day of embryo transfer.
• Endocrine and immune biomarkers, including T cells and uterine natural killer (uNK)/NK cell ratios, were assessed.

Main Results:

• Women undergoing OS exhibited significantly higher serum estradiol, progesterone, and Ghrl compared to non-stimulated groups.
• Patients experiencing miscarriage had lower sex hormone concentrations, with a similar trend observed for Ghrl.
• OS was associated with decreased circulating T cell frequencies and reduced uNK/NK cell ratios, correlating with sex hormone levels.

Conclusions:

• Ovarian stimulation significantly increased serum ghrelin (Ghrl) and sex hormone levels, correlating with immune response and reproductive outcomes.
• While ghrelin showed a similar trend to sex hormones, its statistical significance in relation to miscarriage requires further investigation.
• Specific maternal immunological cut-off values for T cells and uNK/NK cells were identified as predictive of clinical pregnancy and miscarriage.