This is a summary, written by members of the CITF Secretariat, of:
Fell DB, Dimanlig-Cruz S, Regan AK, Håberg SE, Gravel CA, Oakley L, Alton GD, Török E, Dhinsa T, Shah PS, Wilson K, Sprague AE, El-Chaâr D, Walker MC, Barrett J, Okun N, Buchan SA, Kwong JC, Wilson SE, Dunn SI, MacDonald SE, Dougan SD, Risk of preterm birth, small for gestational age at birth, and stillbirth after covid-19 vaccination during pregnancy: population based retrospective cohort study. BMJ 2022; 378 :e071416. doi: 10.1136/ bmj-2022-071416.
The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.
In a CITF-funded study published in BMJ and led by Dr. Deshayne Fell from the University of Ottawa and the Children’s Hospital of Eastern Ontario Research Institute, researchers explored whether COVID-19 vaccination during pregnancy had an effect on preterm birthBirth before 37 completed weeks of gestation., small-for-gestational-age at birth, and stillbirth.
- Vaccination during pregnancy was not associated with any increased risk of overall preterm birth (6.5% among vaccinated vs. 6.9% among unvaccinated), spontaneous preterm birthBirth due to the spontaneous onset of labour before term or preterm premature rupture of membrane. (3.7% vs. 4.4%), or very preterm birthBirth before 32 completed weeks of gestation. (0.59% vs. 0.89%).
- There was no increased risk of small-for-gestational-age at birthDefined as a single live born infant below the 10th centile of the sex specific birth weight for gestational age distribution, based on a Canadian reference standard. (9.1% vs. 9.2%) or stillbirth (0.25% vs. 0.44%).
- Findings were similar by trimester of vaccination, mRNA vaccine product, and number of doses received during pregnancy.
Investigators linked data from Ontario’s provincial birth registry, Better Outcomes Registry & Network (BORN) with the provincial vaccination database (COVaxON) for their evaluation. A total of 85,162 births were included in the study from May 1 to December 31, 2021. 50.6% of those babies (43,099) were born to individuals who received ≥1 dose of COVID-19 vaccine during pregnancy, of whom 42,979 (99.7%) received an mRNA vaccine. In this large cohort, researchers found no evidence that vaccination with an mRNA COVID-19 vaccine during pregnancy was associated with adverse pregnancy outcomes. The results of this study provide further evidence for care providers and pregnant people about the safety of COVID-19 vaccination during pregnancy.