Pregnant with COVID: Large study shows being unvaccinated puts you and your baby in danger

The number of pregnant people who are getting vaccinated is steadily increasing amid the coronavirus current surge, but health experts say the modest improvement is not enough, as those who are expecting continue to get critically ill or die from COVID-19.

The renewed concern comes following a large study published Thursday in "Nature Medicine" that shows unvaccinated pregnant people and their babies may suffer the worst consequences of the virus.

Researchers at the University of Edinburgh Usher Institute analyzed data collected by the COVID-19 in Pregnancy in Scotland study – a national cohort of women who were pregnant on, or became pregnant after, March 1, 2020. The database tracked nearly 145,000 pregnancies in 130,000 women from March 2020 to Oct. 2021.

The study found 98% of pregnant women admitted to critical care were unvaccinated. Researchers reported more than 450 perinatal deaths, when a baby dies in the womb or during the newborn period, all associated with unvaccinated pregnant women. 

“The key take home message that we’d love to get across is that the better way to protect mom and baby is vaccination at the earliest opportunity, and that can be done at any stage in pregnancy,” Aziz Sheikh, study co-author and professor at the University of Edinburgh, said during a press briefing Thursday.

The rate of perinatal mortality for women who gave birth within the study period was higher than the pandemic background rate at 22.6 per 1,000 births compared to 5.6.

The study also found 77% of the nearly 5,000 COVID-19 infections among pregnant women occurred in those who were unvaccinated. Health experts speculate this figure may be higher, as some of the vaccinated pregnant people seeking care may have been hospitalized for reasons other than COVID-19 but tested positive upon admission.

While infections were evenly spread throughout pregnancy, researchers say hospitalizations and critical care admissions occurred more frequently later in pregnancy. Only 6.7% of COVID-related hospitalizations occurred in the first trimester; more than 33% occurred in the third trimester.

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“We’re seeing similar trends overall but our total number of infections (in the U.S.) is much larger than Scotland, so we have seen more maternal deaths,” said Dr. Kathryn Gray, an attending physician in the department of obstetrics and gynecology at Brigham and Women’s Hospital.

Scotland reported a single maternal death throughout the entire study period, while the Centers for Disease Control and Prevention has reported 259 pregnant people have died from COVID-19 since the beginning of the pandemic.

Vaccinations among pregnant individuals in the U.S. have slightly increased from 40% on Dec. 11 to 41.5% by the New Year, the agency reported. Meanwhile, more than 52% of the total vaccinated population in the U.S. are women.

Lack of data in the beginning of the pandemic may have made pregnant people hesitant to get the vaccine, Gray said. But she’s says there's enough data now to prove the COVID-19 vaccine is not only safe but extremely effective at preventing severe disease and death during pregnancy.

“When the vaccine first came out, we had very little knowledge about it and being hesitant about it was very reasonable because we hadn’t even studied it in pregnant individuals,” Gray said. “But now, thousands and thousands of individuals have gotten the vaccine and we see that it’s safe and effective and protect both mom and baby from adverse outcomes.”

Studies have shown antibodies crossing the placenta could protect infants up to three months after birth, she said.

Health experts urge pregnant people to get vaccinated as soon as possible to protect themselves, and their baby. As cases continue to surge from the fast-moving omicron variant, Gray said virus exposure is not a matter of “if” but “when.”  

“During the pandemic, you’re not deciding between vaccination and nothing," she said. "What you’re deciding between is having COVID or having the vaccine." 

Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT. 

Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.

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