In order to determine the frequency of SARS-CoV-2 placental and fetal involvements, we analyzed placentas of 197 women positive for infection at delivery and fetal tissues in cases of pregnancy loss in women positive by SARS-CoV-2 PCR ( N = 2) and COVID-19 serology ( N = 4), using in situ hybridization (ISH), immunohistochemistry (IHC) and, in selected cases, RT-PCR of tissue homogenates. The virus was identified in situ, accompanied by intervillositis, in 2 of 197 placentas (1.02%). In three more cases, SARS-CoV-2 was detected by tissue PCR without in situ localization and placental inflammation. There were no maternal mortality or association of placental infection with the clinical severity of COVID-19. All tested neonates born to SARS-CoV-2-positive women ( N = 172) were negative for the virus. There were three pregnancy losses among 197 infected women and in two cases available fetal tissues were negative for SARS-CoV-2. In one of four fetal autopsies performed in women with positive COVID-19 serology, the mother-to-child transmission (MTCT) could be inferred based on positive SARS-CoV-2 nucleocapsid IHC in fetal pulmonary endothelium. Placental involvement by SARS-CoV-2 is rare, but may be underestimated due to its transient nature. MTCT is even rarer, supporting the protective role of placenta in SARS-CoV-2 infection.
【저자키워드】 SARS-CoV-2, Placenta, Autopsy, Pregnancy, Perinatal, fetal demise, intervillositis, IHC, ISH, 【초록키워드】 COVID-19, Inflammation, immunohistochemistry, Mortality, serology, SARS-COV-2 infection, Infection, Pulmonary endothelium, Transmission, RT-PCR, virus, Neonate, PCR, placental, women, association, Clinical severity, Frequency, Placental infection, SARS-CoV-2 PCR, tissue, protective role, positive, SARS-CoV-2 nucleocapsid, positive COVID-19, selected, tested, analyzed, performed, determine, fetal, tissue homogenates, accompanied, 【제목키워드】 center, Involvement, Infrequent,