COVID-19 vaccine is not associated with adverse birth outcomes

Reference

Fell DB, Dimanlig-Cruz S, Regan AK, et al. 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.

Synopsis

This study used data from the provincial birth registry for the province of Ontario, Canada, between May 1 and December 31, 2021. These data are linked to vaccination database, allowing researchers to link birth outcomes to vaccination status. During this time, there were 85,162 births; 43,099 (50.6%) of them were related to individuals who received at least one vaccine (68.9% received 2 or more doses). Most vaccines were received during the second and third trimesters (87.9%) and were primarily the Pfizer–BioNTech BNT162b2 vaccine (80.1%) or other mRNA vaccines. Vaccination during pregnancy was not associated with any increased risk of overall preterm birth (6.5% vs 6.9%), spontaneous preterm birth (3.7% vs 4.4%), or very preterm birth (0.59% vs 0.89%). The risk of stillbirth and small for gestational age at birth was also not affected by vaccination. The investigators did not find any differences when analyzing by trimester of vaccination, type of vaccine, or number of doses received during pregnancy.