No link between premature births and vaccine against COVID-19

Premature births not linked to COVID-19 vaccine


Vaccination against COVID-19 during pregnancy does not increase the risk of prematurity, concludes a new study published on Monday. 

There would be no link between the increased risk of premature birth or stillbirth and vaccination against COVID-19 during pregnancy, this is what concludes the study carried out by the Research Institute of the Hospital Center for Children of Eastern Ontario (CHEO).

“There was no evidence in our study that COVID-19 vaccination during pregnancy resulted in an increased risk of prematurity, very severe prematurity, low birth weight, or stillbirth,” the lead author said. of the study, Dr. Deshayne Fell. On the contrary, the results provide healthcare providers and pregnant women with additional evidence of the safety of the vaccine during pregnancy.”


Of the 85,162 children born between on May 1 and December 31, 2021 in Ontario, 43,099 were born to people who received one or more doses of COVID-19 vaccine during pregnancy, including 42,979 (99.7%), an mRNA vaccine (usually Pfizer-BioNTech or Moderna).

The study found no association between vaccination during pregnancy and an increased risk of prematurity (6.5% in those vaccinated versus 6.9% in those who were not), spontaneous prematurity (3 .7% against 4.4%) or very prematurity (0.59% against 0.89%). Similarly, the study reported no increased risk of low birth weight (9.1% versus 9.2%) or stillbirth (0.25% versus 0.44%).

“These results were similar regardless of the stage (trimester) of pregnancy in which the vaccine was given, the number of doses received during pregnancy, or the brand of mRNA vaccine administered,” the report said. institute.

CHEO states that “further studies are needed, particularly to assess the effects of vaccination before pregnancy or during the period of conception, as well as the effects of vaccines using another process than mRNA.”

The institute also points out that SARS-CoV-2 infection during pregnancy is associated with an increased risk of complications, including hospitalization and maternal mortality. , but also premature birth and stillbirth.