Bold claim: COVID vaccination during pregnancy not only protects mom from infection, it may significantly lower the risk of preeclampsia and improve birth outcomes. And this is where the conversation gets important, because the evidence is growing and carries real implications for pregnant people and clinicians alike.
Rewritten findings in plain terms: Researchers analyzed records from over 6,000 pregnancies across 40 hospitals in 18 countries, part of the INTERCOVID consortium, to understand how COVID infection and vaccination relate to preeclampsia and other pregnancy complications. They found that infection with SARS-CoV-2 during pregnancy was linked to a higher risk of preeclampsia. In vaccinated individuals, the risk was reduced compared with unvaccinated ones, and the most pronounced protection came with a booster dose, especially for those with existing health conditions.
Key numbers to know:
- Overall, having COVID during pregnancy raised the risk of preeclampsia and other maternal, perinatal problems. Vaccination lowered those risks, and adding a booster provided stronger protection.
- The analysis showed an adjusted odds ratio (aOR) of 1.45 for preeclampsia among those with COVID during pregnancy versus those without, meaning a roughly 45% higher odds when infected.
- Among unvaccinated women, COVID exposure was associated with higher risk, whereas vaccination reduced risk, with booster doses offering the strongest protection (for preeclampsia, the booster group had about a 33% lower odds compared with the baseline unvaccinated group; exact figures varied by subgroups).
- In women with preexisting health issues who received a booster, the odds of developing preeclampsia dropped by as much as 58%. Vaccination also correlated with lower rates of maternal complications, perinatal problems, and preterm birth.
What the researchers did: They compared vaccinated and unvaccinated participants and looked at whether they developed preeclampsia, while adjusting for multiple factors like age, prior pregnancies, obesity, hypertension, diabetes, heart or kidney disease, medications, and where the care occurred. The study design included two matched control participants for each case to strengthen comparisons.
Why this matters: Endothelial dysfunction and inflammatory processes are common pathways in both COVID-19 and preeclampsia. Researchers note that a SARS-CoV-2–induced vascular injury could intensify the pro-thrombotic, anti-angiogenic environment seen in preeclampsia, leading to more hypertensive and placental issues.
What the authors and experts say: Lead author José Villar, MD, MPH, MSc, emphasized that vaccination during pregnancy is a straightforward, protective intervention with meaningful benefits beyond preventing infection. Deborah Money, CM, MD, echoed that the data align with broader literature showing vaccines reduce severe disease and adverse pregnancy outcomes when given before or during pregnancy.
What this means for practice:
- All pregnant people should follow local vaccination guidelines for COVID-19 and other infections included in prenatal protocols.
- Those with preexisting conditions or higher risk for preeclampsia may gain even more from booster doses.
- Healthcare providers, especially primary care clinicians, should actively discuss vaccination with pregnant patients to support informed decisions.
Controversy and reminders for discussion: Some may question the strength of observational data or worry about vaccine safety in pregnancy. While no adverse safety signals were highlighted in this report, ongoing debate about risk–benefit balance remains in some circles. A thoughtful question to the audience: Do you think these findings should change how obstetric care teams counsel pregnant patients about vaccines, or do you feel more evidence is needed before broad recommendations? Would you place greater emphasis on boosters for pregnant individuals with existing health problems, or treat boosters as optional in low-risk pregnancies? Invite comments and alternative viewpoints.
Context and caveats: This study is observational, relying on health records and associations rather than randomized trials. While the results are compelling and consistent with other research, clinicians should integrate these findings with individual patient risk profiles and local guidelines.
