Histopathological changes in the placentas of mothers with a history of coronavirus disease 2019 infection in pregnancy- A comparative cross-sectional study

Abstract

This study aimed to evaluate histopathological changes in the placentas of mothers who had contracted COVID-19 during pregnancy. This prospective study involved the histopathological assessment of two groups of placentas submitted for evaluation to the Department of Histopathology at Khoula Hospital, Oman. The first group consisted of 48 placentas derived from COVID-19-positive pregnant women delivered at the centre between March 2020 and March 2021. The control group consisted of an additional 48 placentas derived from asymptomatic mothers who were not tested for COVID-19 but were assumed to be negative. All placentas underwent gross and microscopic histopathologic examination. Placental lesions were classified according to the Amsterdam system. There was a significantly higher frequency of fibrin thrombi at the terminal villi in placentas derived from the COVID-19-positive group compared to the control group (72.9% versus 0%; p-value = 0.001). Also, villous hypoperfusion was significantly more common in COVID-19-positive placentas than in controls (16.7% versus 0%; p-value = 0.006). However, no significant differences between the two groups were noted with regards to the frequency of other histopathologic features, including decidual vasculopathy, chorioamnionitis, funisitis, intervillositis, perivillous fibrin deposition, and infarction.