Histopathological Features of Placentas from Mothers Infected with COVID-19 During Pregnancy

Purpose: After the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters the body, it can cause morphological changes in various tissues, particularly those of the respiratory system. In pregnant individuals with COVID-19, vertical transmission of SARS-CoV-2 may occur and has been associated with pregnancy complications such as miscarriage, fetal malformations, fetal growth restriction, and stillbirth. This study aimed to investigate the histopathological changes observed in the placentas of women infected with COVID-19 during pregnancy. Materials and Methods: In this study, the histopathological features of the placenta of 29 women with COVID-19 at any period of pregnancy were evaluated. Results: The women included in the study ranged in age from 18 to 40 years, with a mean age of 30.3. The birth weeks of one patient was the 32nd week, eight patients was the 40th week, and the others were at 36 and 39 weeks. None of the patients had comorbidities. In histopathological examination, calcifications, congestive chorionic villi, intervillous hemorrhage and increase in syncytial knots were common findings. Fibromuscular stenosis was observed in 3 cases and marked distal villous hypoplasia in 2 cases. Conclusion: The placenta possesses several mechanisms that act as barriers to prevent the transmission of viral infections to the fetus. Studies have demonstrated an increase in placental pathologies, particularly a higher frequency of maternal vascular malperfusion, in pregnant women with COVID-19. Moreover, these studies have shown that placental abnormalities, including both fetal and maternal vascular malperfusion, may occur in the placentas of mothers infected with COVID-19 during pregnancy.