妊娠中のCOVID-19ワクチン接種が子癇前症予防に新たな知見(COVID-19 vaccination during pregnancy offers new insight into preeclampsia prevention)

2026-02-23

2026-02-20 オックスフォード大学

オックスフォード大学の研究によると、妊娠中の新型コロナワクチン接種が妊娠高血圧腎症(子癇前症)のリスク低減と関連する可能性が示された。大規模な医療データ解析の結果、ワクチン接種群では子癇前症の発症率が有意に低下しており、免疫応答や胎盤機能への影響が関与している可能性があるという。ワクチンは母体と胎児の重症化予防に加え、妊娠合併症の理解にも新たな知見を提供する。研究は因果関係の解明や予防戦略の改善に向けたさらなる検証の重要性も指摘している。

<関連情報>

妊娠中のCOVID-19ワクチン接種状況と妊娠中毒症リスク:INTERCOVIDコンソーシアムのパンデミック時代のコホート COVID-19 vaccination status during pregnancy and preeclampsia risk: the pandemic-era cohort of the INTERCOVID consortium

Paolo Ivo Cavoretto ∙ Jose Villar ∙ Antonio Farina ∙ Marta Fabre ∙ Philippe Deruelle ∙ Agustin Conde Agudelo ∙ et al.
eClinicalMedicine Published: February 18, 2026
DOI:https://doi.org/10.1016/j.eclinm.2026.103785

Summary

Background

We tested whether COVID-19 vaccination affects the risk of preeclampsia (PE) given the well-documented association between COVID-19 and PE, and their overlapping risk factors and pathophysiological pathways.

Methods

We analysed individual level data from pregnant women prospectively enrolled from 18 countries in two consecutive cohorts between 2020 and 2022 during the COVID-19 pandemic using identical methodology. Pregnant women were recruited either with a COVID-19 diagnosis or as concomitant, consecutive, non-diagnosed controls from the same hospitals. Following vaccine availability, vaccination status was documented to define a vaccine-exposed subgroup. Multivariable logistic regression models assessed the odds of PE adjusting for confounders and cohort as a proxy for viral strain, stratifying by pre-existing morbidities and SARS-CoV-2 infection. Survival analyses estimated PE incidence according to vaccination status and pre-existing morbidities.

Findings

Of 6527 pregnant women, 2166 (33.2%) were diagnosed with COVID-19 and 3753 (57.5%) were unvaccinated. Of the 2774 vaccinated women, 1795 (64.7%) received mRNA vaccines; 848 (30.6%) received the initial regimen plus a booster dose, of whom 66.6% received a booster with an mRNA vaccine. We confirmed an independent association between COVID-19 and PE (aOR: 1.45; 95% CI: 1.15–1.84), particularly in unvaccinated women (aOR: 1.78; 95% CI: 1.31–2.42). Overall, after adjusting for confounders, any vaccination gave a protective effect against PE during the index pregnancy (aOR: 0.85; 95% CI: 0.65–1.10), that was stronger with a booster dose (aOR: 0.67; 95% CI: 0.45–0.99). Among women with pre-existing morbidities who received a booster dose the odds were reduced by 58% (aOR: 0.42; 95% CI: 0.20–0.87) – an effect mainly observed in women diagnosed with COVID-19. Adjustment for study site and cohort year did not alter the magnitude of the effect. Vaccination amongst women who received a booster dose was also associated with decreased odds of maternal (aOR: 0.68; 95% CI: 0.55–0.83) and perinatal (aOR: 0.71; 95% CI: 0.54–0.95) morbidity and mortality, and preterm birth (aOR: 0.67; 95% CI: 0.53–0.85).