Endometrial microvessel density for assessing endometrial receptivity during the peri-implantation period

Objective To evaluate the value of endometrial microvessel density (MVD) in assessing the endometrial receptivity during the peri-implantation period. Methods A total of 104 patients undergoing in vitro fertilization and embryo transfer (IVF-ET) treatment were analyzed retrospectively. The subjects were divided into clinical pregnancy group (50 cases) and nonpregnant group (54 cases) according to the IVF-ET outcome. Endometrial tissues were collected 7 days after the natural ovulation prior to IVF-ET for measurement of the endometrial MVD using electron microscopy, which was analyzed in relation to the clinical outcome of the treatment. Results The endometrial MVD was significantly higher in the clinical pregnancy group than in the nonpregnant group [(4.12∓1.84)% vs (3.46∓1.26)%, t=-2.127, P=0.036). ROC curve analysis showed that the MVD had an area under the curve slightly over 0.5 (0.598) for predicting clinical pregnancy, suggesting a poor specificity in predicting the clinical outcome of the treatment. Conclusion In IVF-ET cycles, the endometrial MVD during the peri-implantation period is helpful for assessing the endometrial receptivity, but the specificity remains low.