Largest Study to Date Confirms Safety of COVID-19 Vaccines in Pregnant Women

New research adds to the mounting evidence supporting the safety of Covid-19 mRNA vaccines for pregnant women, with potential benefits for their newborn babies.

The population-based cohort study, published February 6th in JAMA, found that exposure to mRNA COVID-19 vaccination during pregnancy did not increase the risk of adverse events in newborn infants. The study found that babies born to vaccinated mothers were less likely to experience serious complications, including death.

The study involved nearly 200,000 newborns from Sweden and Norway, making it the largest study on this topic to date.

Getting vaccinated can reduce the chances of severe or critical COVID-19 in pregnant individuals. Still, vaccination rates remain lower in pregnant individuals compared to the general population.

“COVID-19 is still present in society and is probably something we will have to deal with for a long time,” Mikael Norman, M.D., Ph.D., lead researcher of the study and professor of pediatrics and neonatal medicine at the Karolinska University Hospital in Stockholm Sweden, stated in an email to MHE.

“It is therefore very important for all women who become pregnant every year to know that vaccination with mRNA-vaccines against COVID-19 is safe for their babies,” he stated.

Using national registers in both countries, the study included 98% of all newborns from women who became pregnant after the Covid-19 vaccines became available. The data collection spanned from June 2021 to January 2023, with all babies followed up for at least one month or as long as they were admitted to a neonatal unit.

The results found no increased risks for newborn infants whose mothers were vaccinated against Covid-19 during pregnancy. Vaccination during pregnancy was associated with lower odds of neonatal intracranial hemorrhage, cerebral ischemia, hypoxic-ischemic encephalopathy, and death. The mortality rate among infants born to vaccinated mothers was only half as high compared to babies whose mothers were not vaccinated.

The study's findings have important implications for healthcare professionals, public health authorities, and expectant parents.

“Despite the fact that the pandemic is over, the study and the results are of great importance for healthcare professionals offering counseling, authorities issuing recommendations, and above all, for anyone who will become pregnant in the future,” Norman stated.

The research was primarily funded by Region Stockholm and the Karolinska Institutet, along with other organizations. The researchers disclosed no conflicts of interest.