Changes in Placentas of Pregnant Women Infected with COVID-19.

SARS-CoV-2 infection in pregnant women can lead to pregnancy-related complications. This work aims to study the spectrum of pathological changes in the placentas of SARS-CoV-2-infected pregnant women. The study involved 50 pregnant women with COVID-19 disease in the first (group I), second (group II), and third (group III) trimesters. Placental sections were examined by histopathology, electron microscopy, and immunohistochemistry to assess structural and molecular changes. The placentas of SARS-CoV-2-affected pregnant women exhibit nonspecific pathological changes, primarily associated with impaired blood circulation. The most frequent findings include thrombosis, chorangiosis, villous edema, and fibrinoid necrosis, all indicative of endothelial dysfunction. Increased expression of sclerostin and Annexin A2 was also detected in affected placentas. The main submicroscopic manifestations of placental insufficiency in COVID-19-affected women are dystrophic-destructive changes in the stroma of the villi, manifested by edema and fibrous processes, which cause significant disruption of the fetoplacental barrier. SARS-CoV-2 causes thrombotic and sclerotic changes, mainly in the maternal portion of the placenta. The manifestation of pathological changes in the placenta of COVID-19-affected women depends on the pregnancy period during which infection by SARS-CoV-2 has occurred. The established findings may provide insights into the connection between COVID-19 in pregnancy and antenatal and perinatal outcomes.