Endometrium cytokine profiles are altered following ovarian stimulation but almost not in subsequent hormone replacement cycles.

PURPOSE: To investigate the impact of ovarian stimulation and hormone replacement treatment on key regulatory cytokines in endometrial secretion during endometrium implantation window.

METHODS: Fifty-six patients undergoing ovarian stimulation (OS) with gonadotropin releasing hormone antagonist and frozen embryo transfer with hormone replacement treatment (HRT) were recruited. Endometrial secretion aspiration was performed repeatedly during implantation window in natural, OS and HRT cycles of every patient. The concentrations of 17 mediators, known to be involved in human embryo implantation, were assessed by multiplex immunoassay.

RESULTS: Compared with natural cycle (NC), the concentration of IFN-γ, G-CSF and IL-8 within endometrium were almost the same following OS and HRT. Furthermore, increased MCP-1 levels were observed following HRT and OS. In addition, an increase in IL-1b, IL-7, IL-17, IL-6, TNF-a, IL-12, IL-4, IL-13, IL-10, IL-5, VEGF and MIP-1b concentrations were found in OS cycle only. The level of GM-CSF was lower in HRT cycle and higher in OS cycle, when compared with NC. Among all 17 cytokines, no correlation was found between cytokine concentrations and serum estradiol and progesterone, while only IL-7 concentration has a low correlation with serum LH level.

CONCLUSION: Compared to natural and hormone replacement cycle, patients' endometrium cytokine profiles present an increased inflammatory response following ovarian stimulation.