Current State of Knowledge about Transplacental Transmission of SARS-CoV-2 Infection

To date, some cases of perinatal transmission of severe acute respiratory syndrome coronavirus-2 (SARS‐CoV‐2) have been reported. However, it is unanswered if these occurred via the trans-placental or the trans-cervical route or through environmental exposure.

To address this question, we conducted this study to review the current state of knowledge about the transplacental transmission of COVID-19.

There are no known placental findings associated with the COVID-19 infection. The possibility of intrauterine infection has been based mainly on the detection of IgM in the neonatal blood. Real time-PCR tests on amniotic fluid, placenta, and cord blood are required to ascertain the possibility of intrauterine vertical transmission.

There is currently no sufficient and convincing evidence about the transplacental transmission of SARS-COV-2 infection in pregnant mothers. However, the paucity of placental expression of ACE-2 involved in the cytoplasmic entry of SARS-CoV-2 may explain its relative insensitivity to transplacental infection.