Pinopodes, leukemia inhibitory factor, integrin-β3, and mucin-1 expression in the peri-implantation endometrium of women with unexplained recurrent pregnancy loss

Objective: To compare pinopode morphology and coverage, and expression of leukemia inhibitory factor (LIF), integrin-beta 3, and mucin-1 (MUC1) in the peri-implantation endometrium of women with unexplained recurrent pregnancy loss (RPL) versus normal fertile women. Design: Exploratory clinical study. Setting: University-affiliated assisted reproductive center. Patient(s): Women undergoing assisted reproduction at centers of reproductive medicine in two university teaching hospitals. Intervention(s): Endometrial biopsy samples were obtained from women with RPL (test group, n = 30) and normal fertile women (control group, n = 26) 7 days after the day of luteinizing hormone peak. Pinopode morphology and coverage were assessed by use of scanning electron microscopy. Expression of LIF, integrin beta 3, and MUC1 were evaluated by immunohistochemical staining. Main Outcome Measure(s): Pinopode morphology and coverage, and the expression of LIF, integrin-beta 3, and MUC1 in both groups. Result(s): Pinopode morphology and coverage, and the expression of LIF and integrin-beta 3 showed no statistically significant differences between the two groups. The expression of MUC1 was statistically significantly reduced in the glandular epithelial cells and endometrial lumen of the RPL group compared with controls. Conclusion(s): The morphology and the coverage of pinopodes and expression of LIF and integrin-beta 3 did not change, but MUC1 expression was statistically significantly reduced in women with RPL compared with normal women. (Fertil Steril (R) 2012;98:389-95. (C) 2012 by American Society for Reproductive Medicine.)