Placental Macrophages Following Maternal SARS-CoV-2 Infection in Relation to Placental Pathology

Introduction In December 2019, a novel coronavirus, SARS-CoV-2, was identified. Whilst pregnant women appear to be at risk of severe infection, pre-term birth, and stillbirth, it is unclear whether placental dysfunction consistent feature maternal SARS-CoV-2 infection during pregnancy. We aim describe the immune response in placentas who had COVID-19 pregnancy investigate there are any associated morphological changes. Methods The testing positive for their were compared contemporaneous controls not known have Samples each placenta sent histopathological analysis or underwent immunohistochemical staining CD163, CD20, CD3, CD31, spike protein. A subset samples transmission electron microscopy. Results There significant increase number CD163 + macrophages Post COVID group (p = 0.0020). no difference percentage CD3 , CD20 cells, but an vascularity 0.026). structural differences observed between EM analysis. However, one from seen several large sub-apical vacuoles syncytiotrophoblast. did observe virions within protein negative sample. Histopathological investigations indicated that specific pathology caused by this cohort samples. Conclusions This study confirm previous studies which possible cases both fetal vascular malperfusion, placentitis COVID-19, association with adverse outcomes. It remains abnormalities exacerbates existing pathology; understanding why some generate these key goal.