Transplacental Transmission of COVID-19

Prospective Evaluation of Transplacental Transmission of SARS-COV-2 (COVID-19) in a Cohort of 10 Mother/Child Dyads

SARS-CoV-2, the agent responsible for pandemic COVID-19 infection, is transmitted mainly by respiratory droplets. Regarding maternal-fetal transmission, even if the mode of transmission from mother to fetus is not clear, some cases of perinatal transmission have been described, but without certainty on the routes of placental contamination, trans-cervical or by environmental exposure. .

The case described by J. Vivanti of a newborn with neonatal neurological involvement and whose mother had been infected during the last trimester of pregnancy reports possible transplacental transmission in a context of positive and elevated viremia in the mother and positive viremia in the newborn.

In 2021, it becomes essential to clarify if and how SARS-COV-2 reaches the fetus, in order to prevent neonatal infection, optimize pregnancy management and better understand the pathogenesis of COVID-19.

SARS-COV-2, ACE2 and TMPRSS2 co-receptors are highly expressed in placental tissues and may be actively involved in transplacental transmission of the virus. From a case of materno-fetal transmission described by our team (publication in progress), we observed placental expression of the Spike SARS-COV-2 protein, but also of the ACE2 receptors, TMPRSS2 and cathepsin L. Cytotrophoblast and syncytiotrophoblast cell stains were positive within the placental villi. Maternal leukocytes were also labeled for these proteins.

Inclusion Criteria:

• Social security affiliation
• Signed informed consent
• Pregnant woman with proven SARS-COV-2 infection during full-term delivery

Exclusion Criteria:

• Patient vaccinated within 15 days prior to inclusion