Age‐related changes in the expression of human endometrial receptivity factors osteopontin, CD44 , and HOXA10 at the window of implantation

Introduction Embryo quality is well established as a factor of infertility with increasing age. Blastocyst implantation receptivity is highest during the window of implantation (WOI). Although the expression of receptivity factors at the WOI is critical for optimal embryo implantation, the impact of female aging on their expression remains unclear. Material and Methods Endometrial tissue slides from healthy fertile women aged 25–46y, at the WOI (day 7–8 post‐LH surge), were stained and analyzed by immunohistochemistry for receptivity factors OPN, CD44, and HOXA10. The analysis was also performed by dividing the samples into two age groups: 25–32 years and 33–46 years. Results Data showed a statistically significant linear decrease in the expression of the proteins OPN, CD44, and HOXA10 ( p < 0.0001, p = 0.0001, and p = 0.0002, respectively) when plotted against women's age. OPN, CD44, and HOXA10 showed linearity with increasing age (R 2 = 0.3209, R 2 = 0.1265, R 2 = 0.1257). Furthermore, a significant decrease in the three proteins was observed between the two age groups, 25–32 years and 33–46 years (OPN: p = 0.0002; CD44: p = 0.0011; HOXA10: p = 0.0273, respectively). Conclusion Endometrial receptivity factors present a negative correlation with increasing age in human endometrial stromal cells, in vitro, at the WOI.