COVID-19 Vaccination During Pregnancy Associated with Reduced Preeclampsia Risk

A prospective cohort study completed in 2026 has found that COVID-19 vaccination during pregnancy, particularly when including a booster dose, is associated with a reduced risk of preeclampsia. The study revealed a 33% reduction in preeclampsia cases among vaccinated pregnant women who received a booster, according to findings published this year.

Researchers investigated the relationship between COVID-19 vaccination and preeclampsia, noting the established link between COVID-19 infection itself and an increased risk of the condition. The study’s findings indicate that unvaccinated women experienced a 78% increase in preeclampsia risk during the pandemic, even as those who contracted COVID-19 during pregnancy faced a 45% increased risk.

The protective effect of vaccination appears to be amplified with booster doses. Data suggests the vaccine, combined with a booster, reduces the odds of preeclampsia by 30%, and can reach as high as 58% in individuals with pre-existing health conditions, or morbidities. The research team examined pathophysiological pathways and overlapping risk factors to understand the observed correlation.

The study builds on earlier research establishing a connection between COVID-19, and preeclampsia. The Lancet published research this year testing whether COVID-19 vaccination affects preeclampsia risk, given the documented association between the two conditions.

Further research is ongoing to determine the precise mechanisms underlying the protective effect of COVID-19 vaccination against preeclampsia.