Chronic Histiocytic Intervillositis: A Placental Histopathologic Feature in Vertical Transmission of Maternal Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

Abstract

Introduction/ObjectiveVertical transmission of severe acute respiratory syndrome associated with coronavirus-2 (SARS-CoV-2) infection has been reported as a rare occurrence. The purpose of this study is to identify any specific placental histopathologic abnormalities associated with SARS-CoV-2 infection, compare differences between mothers with symptomatic and asymptomatic coronavirus disease 2019 (COVID-19), and determine the frequency of vertical transmission.Methods/Case ReportPlacentas from mothers diagnosed with COVID-19 during pregnancy and delivered at Stony Brook University Hospital were identified. A control group of mothers with a negative COVID-19 test was selected from the same period. The frequency of histopathologic characteristics defined by the Amsterdam Placental Workshop Group Consensus was compared using chi-square tests between the following cohorts: COVID-19 positive mothers against COVID-19 negative mothers and symptomatic COVID-19 mothers against asymptomatic COVID-19 positive mothers.Results (if a Case Study enter NA)A retrospective study reviewed 23 placentas from mothers with COVID-19 for features of maternal vascular malperfusion, fetal vascular malperfusion, and inflammatory changes. 11 mothers displayed symptomatic COVID-19, and 12 mothers were asymptomatic. One neonate tested positive for SARS-CoV-2. No significant differences were identified in the frequency of the examined placental histopathologic characteristics between COVID-19 positive and negative mothers. The degree of COVID-19 severity did not significantly impact the frequency of examined histopathologic features. Interestingly, in the case with vertical transmission, the placenta demonstrated the only finding of chronic histiocytic intervillositis (CHI) with associated trophoblast necrosis.ConclusionComparing across groups based on COVID-19 status, this study found no specific placental histopathologic features associated with maternal SARS-CoV-2 infection, regardless of symptom severity. However, in one case of vertical transmission, CHI was a unique histopathologic feature. These findings are consistent with the current literature. Further large-scale investigations are needed to establish additional patterns of specific placental histopathology, incidence and contributing factors of vertical transmission of COVID-19, and the impact of CHI in future pregnancies of affected women.