Differential expression of vascular endothelial growth factor angiogenic factors in different endometrial compartments in women who have an elevated progesterone level before oocyte retrieval, during in vitro fertilization-embryo transfer treatment

Abstract

Objective: To investigate the relationship between endometrial expressions of angiogenic factors around the time of embryo implantation and P level before oocyte retrieval during IVF-ET treatment.

Design: Retrospective study.

Setting: University Assisted Reproductive Unit.

Patient(s): Forty patients were recruited, 20 women with an elevated P level, and 20 women with a normal P level, into cancelled embryo transfer (ET) cycles.

Intervention(s): Endometrial biopsy samples were obtained from women who had an elevated or normal P level 7 days after human chorionic gonadotropin administration. The protein expression levels of VEGF-A, VEGF-C, and PLGF were examined using immunohistochemistry.

Main outcome measure(s): A semiquantitative analysis was performed using histochemical-score analysis of staining intensity in the luminal epithelium, glandular epithelium, and stroma, separately.

Result(s): Luminal epithelial expression of vascular endothelial growth factor (VEGF)-A, VEGF-C, and PLGF did not significantly differ in women with elevated or normal P levels before oocyte retrieval. Glandular epithelial expression of VEGF-A, VEGF-C, and PLGF was higher in women with elevated P levels, compared with those with normal P levels. A significantly higher stromal expression of VEGF-A and PLGF was found in women with elevated P levels.

Conclusion(s): A high P level before oocyte retrieval was associated with expression of VEGF angiogenic factors in glandular epithelium and stromal compartment around the time of embryo implantation. Our findings suggest that the lower implantation rates observed in this group of women may relate to decreased endometrial receptivity arising from altered expression of angiogenic factors.

Keywords: Implantation; angiogenesis; endometrium; progesterone.