The study, led by doctors at BC Children’s Hospital and the University of British Columbia, finds that pregnant women and people had less health issues (defined as new or worsening, or requiring hospitalization) after they were vaccinated, compared to women who are vaccinated but not pregnant.
The study, published in The Lancet Infectious Diseases, is one of the first to compare vaccine side effects between a group of vaccinated pregnant females, an unvaccinated pregnant group, and a vaccinated non-pregnant group. The nearly 200,000 participants were aged 15 to 49 and from seven Canadian provinces and territories.
“In the early stages of the COVID-19 vaccine rollout, there was low vaccine uptake among pregnant people due to concerns about data availability and vaccine safety. This large study helps us better understand the safety of COVID-19 vaccines by looking at changes in health for a large number of pregnant people and comparing that to similar vaccinated and unvaccinated groups,” says Dr. Manish Sadarangani, pediatric infectious disease physician and research study lead. “This study adds to the growing body of evidence that COVID-19 mRNA vaccines are safe during pregnancy.”
The COVID-19 pandemic has disproportionately affected pregnant women and people, who are at higher risk of severe COVID-19 disease compared to people who aren’t pregnant. Canada’s National Advisory Committee on Immunization (NACI) has recommended mRNA vaccines for pregnant people since early 2021.
“Our results demonstrate that these vaccines are safe in pregnancy and, importantly, there was no increased risk of miscarriages or other pregnancy complications,” says Dr. Julie Bettinger, who also worked on the study. “Both healthcare providers and pregnant people should be aware of the more common symptoms pregnant people may experience after vaccination, including redness/pain at the injection site, fatigue, muscle aches, and headaches.”
This study was funded by the Canadian Institutes of Health Research and the Public Health Agency of Canada.
Read the story from the BC Children’s Hospital Research Institute, see or the full study in the Lancet medical journal.