Placenta May Block COVID Transmission To Babies

The reason few pregnant women pass COVID-19 to their newborns, despite experiencing serious complications themselves, may reside in the placenta, a study published by the American Journal of Pathology found.

Photo Insert: Researches believe that, when a woman has COVID-19 in pregnancy, the placenta is shedding off ACE-2 as a way to block [the virus] from being passed to the fetus.

Placentas collected from 16 pregnant people diagnosed with COVID-19 in their second or third trimesters contained lower levels of an enzyme called angiotensin-converting enzyme 2, or ACE-2, than those without the virus, data showed, Brian P. Dunleavy reported for United Press International (UPI).

ACE-2 allows the virus that causes COVID-19 to enter human cells and spread throughout the body, the researchers said. "We think that when a woman has COVID-19 in pregnancy, the placenta is shedding off ACE-2 as a way to block [the virus] from being passed to the fetus," study co-author Dr. Elizabeth S. Taglauer said.

"This may provide important information for therapies and strategies to help prevent other ... infections from continuing to spread," said Taglauer, an assistant professor of pediatrics at Boston University School of Medicine.

Research has indicated that pregnant people with COVID-19 are at higher risk for birth complications, including preterm delivery. However, the risk for their passing the virus to their newborns is low, studies suggest.

For this study, Taglauer and her colleagues collected placentas from two groups of people who delivered babies at Boston Medical Center between July 2020 and April 2021. The first group had normal pregnancies and no confirmed COVID-19 diagnosis, while the second tested positive and had active disease during the second or third trimesters, the researchers said.

The researchers evaluated the presence of ACE-2 in placental tissue using a microscope, they said.

Given that the placenta has many similarities with the lungs, in terms of tissue structure, the findings could help better understand how COVID-19 enters cells and identify ways to prevent infections by controlling ACE-2 levels, according to the researchers.

WEEKLY FEATURE : MVP Group Keeps Lights On During Pandemic