Morphological variants of decidual endometrial transformation in missed abortion after in vitro fertilization

Introduction. High prevalence of early pregnancy loss regardless of methods of conception still remains a relevant problem. One of the ways to identify the etiology of pregnancy loss is a histological examination of the products of conception (POC), decidualization in particular, which often remains underestimated in clinical practice. The aim of the study was to evaluate the decidualization of the endometrium in the retained POC after IVF. Materials and methods.Histological and immunohistochemical analysis of decidualized endometrium was carried out on 153 samples of retained POC around 5–8 weeks of gestation after IVF and on 15 samples of POC after artificial abortion. The POC was fixed in a 10% neutral formaldehyde solution, and a standard histological examination was performed. The immunohistochemical study was carried out to evaluate the expression of estrogen and progesterone receptors in the endometrial glands and stromal cells of the decidualized endometrium compact layer. Results. We verified 5 types of decidual endometrial stromal and glandular transformation of a missed abor-tion material after IVF. The morphological features of decidaulized endometrium in missed abortion after IVF are characterized by a complete and impaired stromal transformation with various types of glandular transformation and disynchronous expression of estrogen and progesterone receptors. Conclusion.We described the morphological variants of the decidual endometrial transformation in POC after IVF, which serve a new direction to the understanding of endometrial factor as one of the main determinants of recurrent implantation and reproductive failure often remaining out of the specialist’s focus. Keywords: missed abortion, complete and incomplete gravidar transformation of the endometrium, estrogen and progesterone receptors, IVF