Safety of Messenger RNA COVID-19 Vaccination During Pregnancy: Findings from Post-Vaccination Follow-Up Data from the Canadian National Vaccine Safety Network.

This communication reports post-vaccination follow-up findings from the Canadian National Vaccine Safety Network on COVID-19 vaccination during pregnancy. Among 6606 pregnant participants who received an messenger RNA COVID-19 primary series, 4302 reported their pregnancy status in follow-up surveys. Within 7 months of vaccination, live birth was the most reported outcome, followed by ongoing pregnancy. Our descriptive analysis indicated pregnancy loss among participants vaccinated in the first trimester (8.9%) appeared to be lower than expected and lower than the rates observed both before and during the COVID-19 pandemic. These findings support the safety of messenger RNA COVID-19 vaccination during pregnancy, including early gestation, and current public health recommendations.