Prof. Cavoretto of Ospedale San Raffaele: first author of a study on the COVID-19 vaccine and reduced risk of preeclampsia

The study, published in eClinicalMedicine, a scientific journal of the prestigious The Lancet group, was led by researchers from the University of Oxford.

It analyzed data from 6,527 pregnant women across 18 countries between 2020 and 2022, comparing vaccinated and unvaccinated women, both with and without SARS-CoV-2 infection, in order to evaluate the impact of vaccination on preeclampsia rates, one of the most serious pregnancy complications.

Preeclampsia is characterized by high blood pressure and signs of organ damage, such as to the kidneys, liver, or nervous system, occurring after the 20^th week of pregnancy. If not diagnosed and managed promptly, it can pose a serious risk to both maternal and fetal health.

The origins of this complication are not yet fully understood, and effective therapies or preventive strategies are still lacking. Preeclampsia does not have a single cause but results from a combination of factors.

However, it is known that infections can contribute to the development of preeclampsia by promoting inflammation and vascular stress, leading to endothelial dysfunction (damage to the inner lining of blood vessels), which in turn causes hypertension and other typical symptoms of the condition.

The study demonstrates that SARS-CoV-2 infection during pregnancy is associated with:

• a 45% increased risk of preeclampsia;
• rising up to 78% among unvaccinated women.

At the same time, the study shows that vaccination:

• reduces the overall probability of developing preeclampsia by 33% among women who received a booster dose, with statistical significance;
• up to a 58% reduction among women with pre-existing comorbidities (such as diabetes, hypertension, or thyroid disorders).

The protective effect of vaccination remained consistent after adjustment for confounding factors and may extend beyond COVID-19 infection itself, suggesting potential benefits in preventing preeclampsia regardless of infection status.

Finally, vaccinated women showed approximately a 30% reduction in the likelihood of preterm birth, as well as maternal and perinatal morbidity and mortality.

Prof. Paolo Ivo Cavoretto, MD, PhD, is Associate Professor of Obstetrics and Gynecology and Head of Maternal-Fetal Medicine at Vita-Salute San Raffaele University and IRCCS Ospedale San Raffaele in Milan, where he works within the Obstetrics and Gynecology Unit.

He graduated with honors in Milan in 1999 and specialized in Obstetrics and Gynecology at San Raffaele in 2005. He completed a clinical-scientific fellowship at King’s College Hospital in London, obtaining a Diploma in Fetal Medicine (FMF). He earned his PhD in 2011 and obtained the Italian National Scientific Qualification as Associate Professor in 2017.

His clinical and research activity focuses on maternal-fetal medicine and high-risk obstetrics, with particular interest in fetal anomalies (including congenital heart disease and spina bifida, as well as fetal surgery), preterm birth, placental dysfunction, and pregnancies achieved through assisted reproduction.

He serves as Editor of Ultrasound in Obstetrics and Gynecology (ISUOG), reviewer for leading journals including those of The Lancet group and JAMA, member of international fetal medicine research groups, and author of approximately 150 scientific publications in high-impact indexed journals (Scopus H-index: 32).