COVID-19 Vaccination During Pregnancy Reduces Preeclampsia Risk

A recent study by the INTERCOVID Consortium has found that COVID-19 vaccination during pregnancy, particularly when accompanied by a booster dose, significantly reduces the risk of preeclampsia. The research, published in eClinicalMedicine, analyzed data from 6,527 pregnant women across 18 countries between 2020 and 2022. The study revealed that COVID-19 infection during pregnancy was associated with a 45% increased risk of preeclampsia, which rose to 78% among unvaccinated women. Conversely, vaccination reduced the overall odds of preeclampsia by 33% among women receiving a booster dose, with even greater protection (42%) observed among women with pre-existing health conditions such as diabetes, hypertension, or thyroid disorders. The protective effect of vaccination remained consistent after adjusting for key factors and may extend beyond COVID-19 infection, suggesting potential benefits for preeclampsia prevention regardless of infection status. Vaccinated women also experienced lower odds of preterm delivery, maternal and perinatal morbidity, and mortality. In addition, among women who received a booster dose, the protective effect for preterm birth was 33%, for maternal morbidity and mortality was 32%, and for severe perinatal morbidity and mortality was 29%, all statistically significant. Professor José Villar, the senior co-author of the study and Principal Investigator of the INTERCOVID consortium from the Nuffield Department of Women's & Reproductive Health, University of Oxford, stated that the findings provide evidence that maternal vaccination may influence pathways involved in preeclampsia development, suggesting a broader immunological or vascular benefit of vaccination.