Their findings showed that the virus didn’t pose a threat to the women’s placentas; however, they found that COVID-19 may have a stronger effect on pregnant women’s immune systems, which can increase their risk for several pregnancy-related complications.
“The good news is the placenta is mounting a robust defense against an infection that is far distant, in lungs or nasal tissue,” said researcher Shelli Farhadian. “On the other hand, the high level of immune system activity might be leading to other deleterious effects on the pregnancy.”
Understanding the health risks
The researchers came to their conclusions after analyzing placenta and blood samples from pregnant women who were infected with COVID-19 and those who were healthy throughout their pregnancies. By examining samples from the various stages of pregnancy, the team was able to gauge what effect the virus had on immune system function.
The team found that women who were infected by COVID-19 early on during their pregnancy lost the use of their ACE2 receptor, which is the entrance point for the virus to infect cells. Conversely, women who weren’t infected maintained the use of their ACE2 receptor throughout their first trimester.
While the loss of the ACE2 receptor shows that infected women’s immune systems were responding to the virus, the researchers say it also made them more susceptible to complications like preeclampsia and premature birth.
Though there is still more to learn about how COVID-19 affects pregnancy and the immune system, the researchers hope these findings highlight some of the risks pregnant women may face during the pandemic.
“It is very important to closely monitor expectant mothers who become infected early in pregnancy,” said Farhadian.