Pregnant women infected with the coronavirus are more likely to become severely ill and die from Covid-19, and they’re at increased risk for premature delivery, according to a pair of reports released Monday by the US Centers for Disease Control and Prevention.

Although the overall risk of severe illness or death remains low, CDC researchers found that pregnant women with coronavirus are more likely to need intensive care, ventilation and heart and lung support than non-pregnant women with the virus.

A separate report found that the rate of preterm birth, when a baby is born before 37 weeks of pregnancy, is 12.9% among women with coronavirus, compared to 10.2% among the general population.

The new research adds to a growing body of evidence that pregnant women are at increased risk when it comes to coronavirus, said Dr. Denise Jamieson, chair of the gynecology and obstetrics department at Emory University School of Medicine.

“It also demonstrates that their infants are at risk, even if their infants are not infected, they may be affected,” Jamieson noted on a call with reporters Monday.

Increased risk for severe illness and death

For one of the reports, researchers reviewed data on 461,825 women between the ages of 15 and 44 who tested positive for Covid-19 between January 22 and October 3. They focused only on those who experienced coronavirus symptoms.

The team adjusted for outside factors and found that pregnant women were more likely to need intensive care, with 10.5 per 1,000 pregnant women admitted to the ICU, compared to 3.9 per 1,000 women who aren’t pregnant.

Pregnant women were 3 times more likely to need help breathing with invasive ventilation than women who aren’t pregnant. Similarly, they were at greater risk of requiring lung and heart support with oxygenation.

They were also more likely to die, with 1.5 deaths per 1,000 pregnant women, compared to 1.2 per 1,000 women who aren’t pregnant.

In keeping with trends seen across the general population, researchers found some racial and ethnic minorities had an even greater potential for infection or severe disease. Among pregnant women, Hispanic women were 2.4 times more likely to die and Asian and Native Hawaiian/ Pacific Islander women had a more pronounced risk for ICU admission, they found.

The team noted that regardless of whether they were pregnant, women over 35 were more likely to experience severe illness.

The researchers said that the greater probability for severe illness among pregnant women might be due to physiological changes in pregnancy, including increased heart rate and decreased lung capacity.

“To reduce the risk for severe illness and death from COVID-19, pregnant women should be counseled about the importance of seeking prompt medical care if they have symptoms and measures to prevent SARS-CoV-2 infection should be strongly emphasized for pregnant women and their families during all medical encounters, including prenatal care visits,” the team wrote.

Medical reference: CNN Health