Pregnant people with COVID-19 have far higher rates of adverse birth outcomes compared to healthy pregnant patients.
The research included 869?,079 women who gave birth over the past year-plus.
The CDC is encouraging pregnant people to get the vaccine, which isn't linked to known safety risks.
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For more than a year, doctors and researchers have noted how pregnancy increases the risk of complications from COVID-19. But a study out this month showed just how dangerous the illness can be for pregnant women and their future babies.
The study, published in JAMA Network Open, looked at 869?,079 women who gave birth at nearly 500 US medical centers between March 1, 2020 and February 28, 2021.
The researchers found the 18,715 patients who had COVID-19 were more than five times as likely to be admitted to the ICU, more than 14 times as likely to need intubation or mechanical ventilation, and more than 15 times as likely to die.
Women with COVID-19 were also about 40% more likely to deliver prematurely.
Study co-author Dr. Jennifer Jolley, an associate professor in UCI Medical Center's OB/GYN department, told the LA Times the stats align with what clinicians are seeing on the ground.
She said she wants her pregnant patients "to get the vaccine as soon as they can moving forward, for their health and for the health of their family."
Past research has shown higher ICU and death rates among pregnant COVID-19 patients
The research - the largest to date using a single database to collect data on childbirth with COVID-19 - upholds past findings showing why pregnant people are considered a vulnerable population, particularly minorities and immunocompromised people.
In the current study, Black and Hispanic women, as well as those with obesity, anemia, and pulmonary artery disease, were disproportionately affected by the disease and its negative outcomes.
A January paper reported that 0.14% of pregnant COVID-19 patients died, compared to 0.005% of pregnant women without the disease. A September 2020 global meta-analysis also found higher rates of ICU admission and ventilation among COVID-19 positive pregnant people compared to non-pregnant COVID-19 patients.
And, a November 2020 CDC analysis looking at data from about 400,000 adolescents and women with symptomatic COVID-19 found those who were pregnant were nearly four times as likely to need ventilation and twice as likely to die than non-pregnant women with COVID-19 of the same age.
It's possible clinicians are more cautious with pregnant COVID-19 patients, contributing to higher rates of ICU admission and even preterm delivery, since they may induce moms early if it seems safer than having them ride out the pregnancy while sick.
The findings underscore the 'urgent' need for vaccination in pregnancy
The report came out right as the Centers for Disease Control and Prevention shifted its COVID-19 vaccination recommendation during pregnancy from neutral to encouraged. As of that day, only 23% of pregnant Americans had received the shot.
Three safety monitoring systems have shown that, unlike the virus, the vaccine isn't linked to any increase in adverse pregnancy outcomes like miscarriage, preterm birth, or death. Plus, the the Delta is more contagious than the original COVID strain and can be more dangerous in anyone infected, pregnant people included.
''The vaccines are safe and effective, and it has never been more urgent to increase vaccinations as we face the highly transmissible Delta variant and see severe outcomes from COVID-19 among unvaccinated pregnant people," CDC Director Rochelle Walensky said in an August 11 statement.