Macroscopic, histopathological and immunohistochemical analysis of placentas from pregnant women with sars-cov-2 infection

Abstract

SARSCoV-2 virus has a predilection for the ACE II receptor (Angiotensin Converting Enzyme II) present in pneumocytes, enterocytes and  trophoblastic cells of the placenta. We studied six cases of placentas of pregnant women positive for PCR for SARS Cov 2. Five cases had significant pathological histories and were infected in the third trimester of pregnancy. Placental weight was below 750 grams in four placentas. Morphologic changes were unspecific: placental aging, intervillous hemorrhage, acute coriamnionitis. We did not observe thrombi. Immunoreactivity for ACE II was positive in decidual cells and   endothelial cells in five of the six cases. We did not observe positivity for ACE II in trophoblast cells. Two cases had congenital malformations, two cases were discharged after observation, one case presented neonatal hypoxia attributed to placental insufficiency (the mother presented preeclampsia) and one case was intrauterine fetal death (the mother was infected in the second trimester, the placenta presented chronic nonspecific villitis and the membranes showed acute chorioamnionitis). We consider that these findings suggest the presence of the virus in maternal tissues and not in chorionic villi. However, placental perfusion was compromised in these cases. Subsequent studies of the placentas of pregnant women will allow us to better understand the pathogenesis of this disease.