[Impact of SARS-CoV-2/COVID-19 on the placenta]

Area of Science:

• Obstetrics and Gynecology
• Infectious Diseases
• Pathology

Background:

• Pregnant women are a vulnerable population for severe acute respiratory syndrome-coronavirus‑2 (SARS-CoV-2) and coronavirus disease-2019 (COVID-19).
• The placenta plays a crucial role in maternal-fetal immune defense against infections.
• Understanding placental changes and vertical transmission is vital for managing COVID-19 in pregnancy.

Purpose of the Study:

• To review morphological placental changes in SARS-CoV-2 infected pregnant women.
• To compare findings with the previous SARS epidemic.
• To discuss the potential for vertical transmission of SARS-CoV-2 from mother to neonate.

Main Methods:

• Review of existing literature and own studies on placental morphology in SARS-CoV-2 infected pregnancies.
• Comparison of pathological findings with SARS cases.
• Analysis of evidence for SARS-CoV-2 presence in placental tissues and umbilical cords.

Main Results:

• Common placental findings include maternal-fetal malperfusion (infarcts, decidual vasculopathy) and thromboinflammation (fetal circulation thrombi, avascular villi).
• Inflammatory reactions such as villitis, intervillositis, and fetal vasculitis can occur.
• SARS-CoV-2 RNA detection in placental tissue and umbilical cord confirms potential for vertical transmission.

Conclusions:

• While no COVID-19 specific pattern exists, placental findings like fetal thrombovasculitis, villitis, intervillositis, and malperfusion suggest SARS-CoV-2 infection.
• SARS-CoV-2 can directly infect the placenta, indicating a risk of vertical transmission.
• These findings highlight the importance of monitoring placental health in pregnant women with COVID-19.