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

Assessment of COVID-19 vaccine safety in pregnancy using population-based data.

Matched case-control study nested in a retrospective cohort.

April 2021-March 2022, England.

All pregnant individuals aged between 18 and 50 years with valid health records.

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.

Adverse pregnancy, maternal and neonatal outcomes.

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 < 7 at 5 min of age (aOR = 0.89, 95% CI: 0.80-0.98) for individuals who received at least one dose of COVID-19 vaccine during pregnancy. The odds of admission to intensive care unit during pregnancy were lower in those vaccinated (aOR = 0.85, 95% CI: 0.76-0.95). There was no association between vaccination in pregnancy and stillbirth, neonatal death, perinatal death and maternal venous thromboembolism in pregnancy.

COVID-19 vaccines are safe to use in pregnancy. Our findings generated important information to communicate to pregnant individuals and health professionals to support COVID-19 maternal vaccination programmes.