Context.—Coronavirus disease 2019 (COVID-19) has been shown to have effects outside of the respiratory system. Placental pathology in the setting of maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remains a topic of great interest as earlier studies have shown mixed results.
Objective.—To ascertain whether maternal SARS-CoV-2 infection is associated with any specific placental histopathology, and to evaluate the virus's propensity for direct placental involvement.
Design.—Placentas from 65 women with polymerase chain reaction-proven SARS-CoV-2 infection underwent histologic evaluation using Amsterdam consensus group criteria and terminology. Another 85 placentas from women without SARS-CoV-2 constituted the negative control group. Sixty-four of the placentas from the SARS-CoV-2-positive group underwent immunohistochemical staining for SARS-CoV-2 nucleocapsid protein.
Results.—Pathologic findings were divided into maternal vascular malperfusion, fetal vascular malperfusion, chronic inflammatory lesions, amniotic fluid infection sequence, increased perivillous fibrin, intervillous thrombi, increased subchorionic fibrin, meconium-laden macrophages within fetal membranes, and chorangiosis. There was no statistically significant difference in prevalence of any specific placental histopathology between the SARS-CoV-2-positive and negative groups. There was no immunohistochemical evidence of SARS-CoV-2 virus in any of the 64 placentas that underwent staining for viral nucleocapsid protein.
Conclusions.—Our study results and a literature review suggest that there is no characteristic histopathology in the majority of placentas from women with SARS-CoV-2 infection. Likewise, direct placental involvement by SARS-CoV-2 is a rare event.
Ke Cheng (founder, CEO) and Justin David Mann are affiliated with and represent HistoWiz Inc. The other authors have no relevant financial interest in the products or companies described in this article.