LAUSR

Abstract Controversies surrounding the effect of ES on pregnancy outcome in women with RIF are mostly due to the poorly defined target population. We evaluated the effect of ES on clinical outcomes in women with strict criteria of RIF before IVF/ICSI. We also examined the effect of ES on the expression of markers of endometrial receptivity. Women with failed implantation after transfer of seven or more top quality day 3 embryos or three blastocysts underwent the scratch procedure on exact days of the cycle prior to IVF/ICSI. Results were compared to no scratch control group. Using histopathology, immunohistochemistry, and scanning electron microscopy, we also examined the effect of injury on the endometrial receptivity in a separate series of observations with double ES. Cumulative pregnancy rate was significantly higher in the study group as compared to control (54.8% vs. 29.0%; p < .05). The effect of ES on the clinical outcome was seen during fresh ET, but not on the next FET cycles. ES improves impaired endometrial receptivity by partially normalizing the expression of estrogen and progesterone receptors (ERs, PRs) and pinopodes. We concluded that in a well-defined subpopulation of infertile women with RIF, ES significantly enhances pregnancy rates. ES has a specific impact on endometrial receptivity normalizing the expression of some markers.