Objective: There are no well-defined findings about reasons for first trimester abortion in some pregnancy cases. Selectins are cell adhesion proteins which are important for blastocyst implantation in the decidua. The goal of the study was to investigate the role of selectins in first trimester pregnancy loss by immunohistochemistry.
Study design: Decidual and placental tissue samples have been obtained from the women with unwanted pregnancy as the control group (n = 40) and missed abortion (n = 40) as the study group. Immunohistochemistry technique has been used to compare P, L and E-selectin expression of the fibroblast and the decidual cells in uterine decidual stroma; and fibroblasts and mesenchymal cells in placental villous stroma. Immunostaining for P, L, E-Selectin has been evaluated semiquantitatively by HSCORE analysis.
Results: Decidual cells, for E and L-selectin showed stronger staining in the study group than controls, and the difference was statistically significant (p = 0.007, p = 0.007). P-selectin showed stronger staining in the control group, but the difference was not as significant as the E and L-selectins (p = 0.04). In the placenta, cytotrophoblasts and syncytiotrophoblasts showed stronger staining for P, E, L-selectins for the control group (p < 0.007, p = 0.001 and p < 0.001, respectively).
Conclusion: Strong expression of each of the three investigated selectins in healthy pregnancy villi shows their contribution to implantation and strong placentation. There is a need for better understanding of the functions of adhesive molecules in these events to reveal unknown causes for pregnancy loss.