SARS-CoV-2 Is Persistent in Placenta and Causes Macroscopic, Histopathological, and Ultrastructural Changes

Area of Science:

• Virology
• Obstetrics
• Pathology

Background:

• Coronaviruses, including SARS-CoV and MERS-CoV, have been linked to adverse outcomes in pregnant individuals.
• The COVID-19 pandemic prompted investigations into the effects of SARS-CoV-2 on pregnancy and placental health.

Observation:

• This study examined five pregnant women infected with SARS-CoV-2 in Brazil between August 2020 and January 2021.
• Placental tissues were analyzed macroscopically, histopathologically, and ultrastructurally, compared to a prepandemic control group.
• SARS-CoV-2 RNA was detected in 3 of 5 placentas, and viral spike protein was present in all analyzed placentas.

Findings:

• Macroscopic placental findings included vascular congestion, fibrin deposition, infarcts, and calcifications.
• Histopathology revealed fibrin deposition, inflammatory infiltrate, necrosis, and vascular thrombosis.
• Ultrastructural analysis showed apoptosis and virus-like particles in infected placentas.

Implications:

• SARS-CoV-2 infection leads to significant placental alterations, impacting fetal development and potentially contributing to adverse pregnancy outcomes.
• These findings highlight the importance of monitoring pregnant women for SARS-CoV-2 and understanding its potential for vertical transmission.
• Further research is needed to elucidate the long-term consequences of SARS-CoV-2 placental pathology.