COVID-19 Vaccines in Pregnancy: A Potential Shield Against Preeclampsia
A groundbreaking multinational study from the INTERCOVID Consortium, led by researchers from the University of Oxford, has revealed a significant link between COVID-19 vaccination during pregnancy and a reduced risk of preeclampsia, a serious pregnancy complication. The findings, published in eClinicalMedicine, offer a unique perspective on preeclampsia prevention, independent of the direct effects of COVID-19 infection.
The study, which analyzed data from 6,527 pregnant women across 18 countries, found that:
COVID-19 infection during pregnancy increased the risk of preeclampsia by 45%, with unvaccinated women facing a 78% higher risk.
Vaccination, especially with a booster dose, significantly reduced the odds of preeclampsia by 33%.
Women with pre-existing health conditions like diabetes, hypertension, or thyroid disorders experienced a 42% reduction in preeclampsia risk after vaccination with a booster.
The protective effect of vaccination persisted even after accounting for various factors, suggesting potential benefits for preeclampsia prevention, regardless of infection status.
Vaccinated women also had lower odds of preterm delivery, maternal and perinatal morbidity, and mortality.
Among women with booster doses, the protective effect against preterm birth was 33%, maternal morbidity and mortality was 32%, and severe perinatal morbidity and mortality was 29%, all statistically significant.
Professor José Villar, the senior co-author of the study, emphasized that these results extend beyond the known benefits of COVID-19 vaccination in pregnancy. He suggested that maternal vaccination may influence pathways involved in preeclampsia development, indicating a broader immunological or vascular benefit.
Understanding Preeclampsia and its Causes
Preeclampsia, affecting 3-8% of pregnancies worldwide, is a leading cause of maternal and neonatal morbidity and mortality. Its origins remain unknown, but inflammation and vascular dysfunction are known contributors, overlapping with COVID-19 infection. The INTERCOVID findings support the idea that vaccination may modulate immune and vascular pathways, potentially offering protection even without COVID-19 infection.
Global Implications
Professor Paolo Ivo Cavoretto of IRCCS San Raffaele Hospital in Milan, Italy, highlighted the global significance of these findings. He stated that this is the first large-scale, prospective evidence showing that COVID-19 vaccination, particularly with boosters, may help prevent preeclampsia. The protective effect is most pronounced among women with underlying health conditions, who are at the highest risk.
The study's paper, 'COVID-19 Vaccination Status During Pregnancy and Preeclampsia Risk: The Pandemic-Era Cohort of the INTERCOVID Consortium,' is published in eClinicalMedicine.
