Babies born to unvaccinated people who had COVID-19 may be at greater risk of respiratory distress: Study

Unvaccinated pregnant people who contracted COVID-19 were more likely to have babies who suffered from respiratory distress, a new study published this week found.

A team of researchers led by the University of California, Los Angeles, looked at 221 pregnant people for the study, including 151 who were unvaccinated before they were infected with COVID, which was confirmed with a laboratory test.

All of the 151 unvaccinated pregnant people met the National Institutes of Health criteria for severe or critical COVID-19 whereas only 4% of the 70 vaccinated pregnant people met the criteria.

Researchers were able to examine 199 babies, all of whom were born between April 2020 and August 2022, and none of whom tested positive for the virus. The remaining 28 fetuses either resulted in a miscarriage, abortion or fetal demise, or could not be followed up with.

The team found that being exposed to COVID-19 in utero "may activate an inflammatory cascade" in the airways of newborns, resulting in respiratory distress. One of the main pathways appear to be associated with the function of cilia, the tiny, hair-like structures found on the surface of cells that typically help push germs, mucus and other particles towards the mouth so they can be coughed or sneezed out.

Results, published in the journal Nature Communications, found the odds of respiratory distress were up to three times greater in babies born in those who were unvaccinated versus those who were vaccinated.

"We found unusually high rates of respiratory distress shortly after birth in the full-term babies born to mothers who had COVID-19 during pregnancy," Dr. Karin Nielsen, a professor of pediatrics in the division of pediatric infectious diseases at UCLA's David Geffen School of Medicine, said in a statement. "The mothers had not been vaccinated prior to acquiring COVID, indicating that vaccination protects against this complication."

Further research is needed to determine if COVID-19 still impacts respiratory distress when accounting for other factors that lead to respiratory distress syndrome

Respiratory distress in infants is defined as difficulty breathing or working harder to breathe within the first 24 hours. Signs can include wheezing, sweating, changes in breathing rate or color changes around the lips or mouth, according to Johns Hopkins Medicine.

Research has shown that pregnant people with COVID-19 are at increased risk of becoming seriously ill leading to hospitalization, intensive care, the use of a ventilator or even death. COVID-19 during pregnancy also raises the risk of a premature or stillborn baby.

"Our results demonstrate that maternal vaccination against COVID-19 not only protects against maternal disease severity, but also reduces the likelihood of neonatal [respiratory distress]," the authors wrote.

The study had several limitations, such as a small and homogenous sample size and a wide estimate range, which impacted generalizability. More research is needed to validate these findings.

The Centers for Disease Control and Prevention (CDC) currently recommends that all pregnant people get vaccinated against COVID-19 and that studies have shown there are no safety concerns for babies born to those who have been vaccinated.