COVID‐19 Vaccine Safety in Pregnancy, A Nested Case–Control Study in Births From April 2021 to March 2022, England

ABSTRACT Objective Assessment of COVID‐19 vaccine safety in pregnancy using population‐based data. Design Matched case–control study nested in a retrospective cohort. Setting April 2021–March 2022, England. Population or Sample All pregnant individuals aged between 18 and 50 years with valid health records. Methods Individuals identified from the national Maternity Services Data Set (MSDS) had their records linked to hospital admission, national COVID‐19 vaccine and COVID‐19 testing databases. Matching included participant's age and estimated week of conception. We compared outcomes across multiple COVID‐19 vaccine exposures using conditional multivariable logistic regression, adjusting for demographic and health characteristics. Main Outcome Measures Adverse pregnancy, maternal and neonatal outcomes. Results 514 013 individuals were included. We found lower odds of giving birth to a baby who was low birthweight (aOR = 0.86, 95% CI: 0.79–0.93), preterm (aOR = 0.89, 95% CI: 0.85–0.92) or who had an Apgar score