COVID-19 Vaccination During Pregnancy Linked to Reduced Preeclampsia Risk

New research indicates that COVID-19 vaccination during pregnancy, particularly with booster doses, is associated with a significant reduction in the risk of preeclampsia, a serious pregnancy complication. The findings come from an international study led by the University of Oxford and involving the Health Research Institute of Aragon (IIS Aragón) in Spain.

Understanding Preeclampsia

Preeclampsia is a life-threatening condition that develops during pregnancy, characterized by high blood pressure and potential organ damage in the mother and can impair fetal development. Globally, it contributes to over 70,000 maternal deaths and 500,000 neonatal deaths annually, often leaving lasting health problems for both mother and child. University of Oxford

Key Findings of the International Study

The study, titled “Covid-19 vaccination status during pregnancy and risk of preeclampsia: the Intercovid Consortium pandemic-era cohort,” analyzed data from 6,527 pregnant women across 41 centers in 18 countries between 2020 and 2022. Researchers compared vaccinated and unvaccinated women, with and without SARS-CoV-2 infection, to determine the impact of vaccination on preeclampsia rates. Aragón Hoy

• COVID-19 Infection Risk: COVID-19 infection during pregnancy was linked to a 45% increased risk of preeclampsia. This risk rose to 78% among unvaccinated pregnant women.
• Vaccination Effectiveness: Vaccination reduced the overall odds of preeclampsia by 33% in women who received a booster dose.
• Boosters and Pre-existing Conditions: Booster vaccination demonstrated even greater protection, reducing the risk of preeclampsia by 58% in women with pre-existing conditions like diabetes, hypertension, or thyroid disorders.
• Additional Benefits: Vaccinated women also experienced lower rates of preterm birth, maternal and perinatal morbidity, and mortality. Booster doses were associated with a 33% reduction in premature birth, a 32% reduction in maternal morbidity and mortality, and a 29% reduction in severe perinatal morbidity and mortality.

New Diagnostic Test for Preeclampsia

Alongside vaccination efforts, a new diagnostic test for preeclampsia developed by researchers at the Nuffield Department of Women’s & Reproductive Health at the University of Oxford is being adopted internationally. This test accurately identifies women at risk of developing the disease by measuring the levels of two molecules produced by the placenta in the mother’s blood. The test has a 70% positive predictive value and a low rate of false negatives. University of Oxford

Early Screening and Prevention

Current diagnostic methods for preeclampsia, relying on blood pressure and urine protein levels, can be unreliable and produce false positives. Early screening using angiogenic and antiangiogenic markers, such as Placental Growth Factor (PlGF) and soluble fms-like Tyrosine Kinase-1 (sFlt-1), can predict early-onset preeclampsia with a 90% accuracy rate, though it can be costly. PubMed A two-step screening model focusing PlGF testing on patients initially classified as intermediate risk may offer a cost-effective alternative.

Looking Ahead

These findings underscore the importance of COVID-19 vaccination during pregnancy for both maternal and fetal health. Continued research and implementation of improved diagnostic tools will be crucial in preventing and managing preeclampsia, a leading cause of maternal and neonatal morbidity and mortality worldwide.