Why COVID Infection Raises Risks in Pregnancy

MONDAY, April 26, 2021 (HealthDay News) -- A strong immune response to the virus that causes COVID-19 by the placenta may help explain why infected pregnant women face a higher risk of complications, such as preterm birth and preeclampsia, researchers say.

The Yale University team analyzed blood and placental tissue from 39 women at different stages of pregnancy.

They detected evidence of the SARS-CoV-2 virus in two samples of placental tissue, and also found that placentas in infected women tended to have much more immune system activity than the placentas of non-infected women.

"The good news is the placenta is mounting a robust defense against an infection that is far distant, in lungs or nasal tissue," said study author Dr. Shelli Farhadian, assistant professor of internal medicine (infectious diseases) and neurology.

"On the other hand, the high level of immune system activity might be leading to other deleterious effects on the pregnancy," she said in a Yale news release.

While the virus itself may cause problems, researchers from the U.S. Centers for Disease Control and Prevention found recently that COVID-19 vaccination during pregnancy is safe.

Farhadian said it is important to closely monitor women who become infected with COVID early in pregnancy.

She noted that there's been little research into immune system activity in the placenta during infections like COVID-19, and it's not known if other types of infections would behave similarly to SARS-CoV-2.

The findings were published online April 22 in the journal Med.

More information

The U.S. Centers for Disease Control and Prevention has more on COVID-19 and pregnancy.

SOURCE: Yale University, news release, April 22, 2021