COVID-19 vaccinations protect pregnant women and their babies.

COVID-19 vaccinations protect pregnant women and their babies.

COVID-19 vaccination protects pregnant women

Pregnant people who received a COVID-19 vaccine were much less likely to be seriously ill or have their babies born prematurely, according to a major new study led by UBC and published inJAMAwas published.

The research was based on data from nearly 20,000 pregnancies in Canada and showed that vaccination was strongly associated with a lower risk of hospitalizations, intensive care admissions and premature births. These advantages remained as the virus evolved from the Delta variant to the Omicron variant, which has evolved into newer sublineages that still dominate today.

"Our results provide clear, population-based evidence that COVID-19 vaccination protects pregnant people and their babies from serious complications. Even as the virus evolved, vaccination continued to provide significant benefits for mother and child." 

Dr. Deborah Money, professor of obstetrics and gynecology at UBC and lead author of the study

The study was conducted by the national CANCOVID-Preg surveillance network, led by UBC researchers and representing one of the largest data sets on COVID-19 and pregnancy in the world.

The results showed that vaccinated people were about 60 percent less likely to be hospitalized and 90 percent less likely to receive intensive care treatment compared to unvaccinated people at the time of infection. In addition, a connection was found between the vaccination and a lower number of premature births (births before 37 weeks of pregnancy), reducing the risk by 20 percent during the delta wave and by 36 percent during the omicron wave.

Notably, the analysis found that people who were vaccinated during pregnancy had even lower rates of preterm birth and stillbirth compared to those who were vaccinated before pregnancy.

“There is never a bad time to get vaccinated – whether you are currently pregnant or planning to become pregnant,” said Dr. Elisabeth McClymont, lead author and assistant professor in the UBC Department of Obstetrics and Gynecology. “However, our data suggests that there may be additional benefits to receiving the vaccine during pregnancy.” 

Information on vaccination recommendations for pregnant women

The findings come as vaccination recommendations for pregnant people are changing in some regions. 

In the US, the Immunization Recommendation Committee (ACIP) recently did not include a specific recommendation for COVID-19 vaccination during pregnancy in its updated adult vaccination plan. Meanwhile, health experts in Canada and the World Health Organization continue to recommend that pregnant people receive a COVID-19 vaccine.

The researchers say their findings provide timely evidence to inform ongoing policy discussions.

“The evidence is overwhelmingly clear: COVID-19 vaccination is safe and effective during pregnancy,” said Dr. Money. “These latest results provide important information for pregnant women and their healthcare providers and strongly support public health recommendations regarding vaccination during pregnancy.” 

A pan-Canadian effort

The analysis included data from nine Canadian provinces and one territory. Researchers used population-based health data to track outcomes from nearly 20,000 pregnancies affected by SARS-CoV-2 between April 2021 and December 2022.

Even after they took into account factors such as age, body mass index and pre-existing conditions such as high blood pressure or diabetes, vaccination remained associated with significantly lower risks of hospitalization.

Beyond COVID-19, researchers say the study underscores the importance of including pregnant people in vaccine research and planning for future respiratory virus outbreaks.

“Pregnancy is a unique period of vulnerability, but also an opportunity for prevention,” said Dr. McClymont. “This study reinforces how vaccinations can make a real difference to the health of mothers and newborns.”

The study was funded by the Public Health Agency of Canada through the COVID-19 Immunity Task Force, the Canadian Institutes of Health Research and the BC Women's Health Foundation.

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