Endometrial markers of uterine receptivity utilizing the donor oocyte model

BACKGROUND: Ethical constraints limit the ability to study peri-implantatio n phase human endometrium. In this study, the donor oocyte model was used t o study candidate endometrial markers of uterine receptivity. METHODS: Arch ived, paraffin-embedded tissue obtained by endometrial biopsy during cycle days 21-23 of patients undergoing 'mock' hormonal treatment cycles were eva luated by standard histological criteria and immunohistochemical staining f or alphav beta3 integrin and glycodelin. All of these patients (n = 101) ha d undergone a donor oocyte embryo transfer cycle utilizing the exact same h ormonal protocol. RESULTS: Histological evaluation revealed 62 (61.3%) in-p hase, 34 (33.7%) dyssynchronous, 2 (2.0%) immature and 3 (3.0%) advanced en dometria. The clinical outcomes of patients with either in-phase or dyssync hronous endometria were similar. Very strong correlations were noted betwee n endometrial glandular dating and either alphav beta3 integrin or glycodel in immunostaining intensity (P < 0.001 for both). Glycodelin and <alpha>v b eta3 integrin immunostaining intensities were also highly correlated with e ach other (P < 0.001). CONCLUSIONS: Throughout the time period correspondin g to the putative window of maximal endometrial receptivity (cycle days 21- 23) a dynamic process was observed in exogenous hormonal replacement cycles characterized by a rapid histological advancement of endometrial glandular elements as well as progressive <alpha>v beta3 integrin and glycodelin exp ression.