Placental pathology from COVID-19-recovered (nonacute) patients

Placental pathology can identify characteristic features of specific infectious pathogens. The histopathology of acute SARS-CoV-2 placental infection and exposure without infection has been well described. However, whether the characteristic placental pathology persists after the acute phase of the infection is less clear. We retrospectively identified 67 COVID-19-recovered pregnant patients who had placental pathology available. After reviewing the gross and histopathology, we categorized the findings and studied the placentas for evidence of chronic infection by immunohistochemistry for the spike protein of the virus. We found these placentas showed significantly increased prevalence of maternal and a trend towards significance of fetal vascular malperfusion when compared to a control group of placentas examined for the sole indication of maternal group B streptococcal colonization. None of the COVID-19-recovered placentas showed expression of the viral spike protein; therefore, we found no evidence of persistent infection of the placenta in women with a history of COVID-19 during their pregnancy. We conclude that recovery from a SARS-CoV-2 infection during pregnancy puts the pregnancy at risk for specific pathology.