Covid-19 risks during pregnancy 1:19
(CNN) --
Pregnant women and their babies are at greater risk of serious effects if they catch Covid-19, and now a wide-ranging international review is helping to underscore just how devastating those risks can be.
The review is based on data from 12 studies from a large set of countries, including the United States.
In total, the studies included more than 13,000 pregnant women, of whom some 2,000 had a confirmed or probable case of covid-19.
The health outcomes of these women and their babies were compared with those of some 11,000 pregnancies in which the mother tested negative for covid-19 or antibodies against this disease at the time of delivery.
CDC finds potential safety issue in Pfizer's updated Covid-19 vaccine, but recommends no changes to vaccination practices
Across all studies, about 3% of pregnant women with COVID-19 required intensive care, and about 4% required some form of critical care, but this was much higher than for pregnant women who required such care outside of a covid-19 infection.
Compared with uninfected pregnant women, those who contracted covid-19 were almost 4 times more likely to be admitted to an intensive care unit.
They were 15 times more likely to be put on a ventilator and 7 times more likely to die.
They also had a higher risk of preeclampsia, blood clots and problems caused by high blood pressure.
Babies born to mothers who had covid-19 were at higher risk of preterm delivery and low birth weight.
Previous studies suggest that covid-19 may increase the risk of stillbirth, but this study did not find that same relationship.
Risks persist in all countries
Still, the results paint a clear picture showing that covid-19 infections amplify pregnancy risks.
advertising
"It is very clear, and even consistent, whether we are talking about Sweden, where pregnancy outcomes are generally excellent, or about other countries with higher maternal morbidity and mortality problems, that the presence of covid-19 during pregnancy increases the risk for both mother and baby," says Emily Smith, lead author of the study and associate professor of global health at The George Washington University.
The study has some caveats that may limit the applicability of the results to pregnant women in the omicron variant era.
How is the new variant of the covid XBB.1.5 and why is it spreading rapidly
First, the studies were conducted relatively early in the pandemic, when most people were not yet vaccinated or previously infected.
This means that the people in the study were likely at higher risk not only because they were pregnant, but also because they were immunologically naive to the virus, meaning they did not have any pre-existing immunity to help them fight infections.
Since then, many pregnant women have been vaccinated or previously infected with covid-19, or both.
In the first week of January, about 72% of pregnant women in the US had received the initial covid-19 vaccine schedule, and it is estimated that about 95% of Americans have had covid-19 at least once, or have been vaccinated against it, according to data from the Centers for Disease Control and Prevention (CDC).
This means that they likely have some immune memory against the virus that can help protect them against serious outcomes.
However, that immune memory seems to fade over time.
CDC data shows that only 19% of pregnant women have received an updated booster, which means that many people may not have as much protection against the virus as they think.
The study's lead author, Emily Smith, an associate professor of global health at George Washington University, says the study results reflect the risk of Covid-19 and pregnancy in unvaccinated people.
Unfortunately, Smith says, many countries still don't have clear guidelines advising vaccination during pregnancy.
And there are some parts of the world, such as China, that still have substantial proportions of their population that have never been infected.
The testimonies of the (still) undefeated to covid-19 after more than two years of pandemic: luck, genetic immunity or vaccination?
Vaccination is vital
For people trying to weigh the risks and benefits of vaccinating against COVID-19 during pregnancy, Smith says this study helps tip the scales firmly in the side of vaccination.
"It pays to protect yourself during pregnancy," says Smith.
She states that this study did not look at the benefits of vaccination during pregnancy, but that other studies have, showing large decreases in the risk of stillbirth, preterm birth, and serious illness or death in the mother.
"And that's the side story," Smith said.
Dr. Justin Lappen, director of the Cleveland Clinic's division of Maternal-Fetal Medicine, praised the study, saying its findings reinforce and improve on previous research, which has found that COVID-19 markedly increases the risk of serious outcomes for the mother. mother and baby.
He did not participate in the study.
Lappen affirms that the results highlight the importance of preventing and treating covid-19 in pregnant women.
Indicated or recommended treatments should not be stopped specifically due to pregnancy or lactation, Lappen wrote in an email to CNN.
The study was published in the academic journal BMJ Global Health.
Covid-19Pregnancy