ABSTRACT
Introduction. The multinucleated syncytiotrophoblast of human placental villi is responsible for transport functions between the maternal and fetal circulation and is the main site of protein synthesis and steroid production. It is formed by the fusion of underlying cytotrophoblast cells. The nuclei of the multinucleated syncytiotrophoblast are nonmitotic, but the mechanism of cell cycle arrest in the syncytiotrophoblast is not known. Single publications have described that cell fusion induces a cellular senescence, best known as a component of the stress response and an important factor in preventing tumor cell growth. For syncytiotrophoblast, one of the criteria of its aging is the formation of so-called syncytial nodes - local accumulations of nuclear material with protrusion of these cells into the interstitial space. The purpose of the study. To determine the morphological features in women's placentas under the influence of chronic stress caused by coronavirus disease and internal irradiation, with the subsequent formation of criteria for diagnosing diseases and assessing the severity of lesions in the mother and fetus. Material and methods. A morphological study of syncytial nodules in the villi of the placenta of groups of women with chronic stress due to internal irradiation and COVID-19 (classified by severity of the disease) was performed in comparison with the physiological course of pregnancy and childbirth. Histopathological and ultrastructural examination of placentas was performed with the detection of syncytial nodes with morphometric analysis of their ultrastructural features of the nuclear component of syncytiotrophoblast nodules and their comparison in clinical groups. The number of syncytial nodes was estimated on histological specimens stained with hematoxylin and eosin. The effect of chronic stress in women was significantly (p<0.05) confirmed by increased cortisol levels (saliva test). Statistical processing of the results was carried out using licensed programs «Microsoft Excel» and «Statistica». The design of the study and all methods used in this study were reviewed and approved by the Bioethics Committee of the State Institution «Institute of Pediatrics, Obstetrics and Gynecology named after Academician O.M. Lukyanova of the National Academy of Medical Sciences of Ukraine», Kyiv, Ukraine. Results of the study. Morphological examination of the placental tissue of parturient women with COVID-19 showed an increase in the number of syncytial nodes in the villi, which we associated with the presence of stress. Ultrastructural studies revealed changes in the nuclei of syncytial nodules depending on the pathology. Conclusion. An increase in the number of syncytial nodes in the chorionic structures in internal radiation and COVID-19 in pregnant women has been established, which is important as predictors of placental factors for the health of the individual in the future. © Yu. Bondarenko, T. Zadorozhna, 2022.