The role of VEGF and its receptors in the etiology of early pregnancy loss

Objective: This study aimed to investigate the role of vascular endothelial growth factor (VEGF) and its receptors (VEGFR1, VEGFR2) in maternal and embryonic tissues in the etiology of early pregnancy loss. Methods: Immunohistochemistry was used to analyze the expression of VEGF and its receptors in placental and decidual tissues of 80 women with spontaneous incomplete abortion (n = 20), missed abortion (n = 20), blighted ovum (n = 20) and from early terminated pregnancies (n = 20). Results: Compared with the controls, all study groups showed weaker VEGF immunoreactivity in cytotrophoblasts and syncytiotrophoblasts of placental villi and endothelial cells of decidua (p = 0.002, p = 0.003, p<0.001 respectively). Decidual endothelial cells of study groups except for blighted ovum showed weaker VEGFR1 immunoreactivity as compared to controls (p<0.001). Placental villi cytotrophoblasts, syncytiotrophoblasts, decidual endothelial cells and endometrial gland epithelial cells showed weaker VEGFR2 immunoreactivity in all study groups compared to controls (p<0.001). Placental villi endothelial cells showed the weakest VEGFR2 immunoreactivity in incomplete abortion group and the strongest staining in the blighted ovum group (p<0.001). Conclusion: These results suggest that decreased expression of VEGFR1 in decidua and weaker VEGF and VEGFR2 expression in placental villi and decidua may be associated with early pregnancy loss.