An analysis of more than 400,000 women who are between 15 and 44 years old and diagnosed with COVID-19 revealed that those who were pregnant had a 70% increased risk of dying compared to those who were not, according to the Centers for Disease Control and Prevention.

Invasive ventilation, intensive care unit admission and ECMO were also more common among pregnant than nonpregnant women. ECMO stands for extracorporeal membrane oxygenation. It’s a procedure that removes blood from your body, runs it through a machine that clears it of carbon dioxide and inserts oxygen-rich blood back into the body.

The new study, released Monday, comes after an earlier report from June that found similar results on pregnant women and COVID-19 — except for an increased risk of death from the disease. Pregnant women who are 35-44 years old and positive for COVID-19 were nearly four times as likely to require invasive ventilation and twice as likely to die than nonpregnant women of the same age. What’s more, Hispanic women had 2.4 times the risk of death.

“Understanding the risk posed by SARS-CoV-2 infection in pregnant women can inform clinical practice, risk communication and medical countermeasure allocation,” the report reads. “Pregnant women should be informed of their risk for severe COVID-19-associated illness and the warning signs of severe COVID-19.”

Between Jan. 22 and Oct. 3, about 409,000 women in the case study had symptomatic COVID-19, including 23,434 pregnant women — 34 of whom died, equaling 1.5 deaths per 1,000 cases. Of the 386,028 nonpregnant women who tested positive for COVID-19, another 447 died from coronavirus complications, or 1.2 deaths per 1,000 cases, the CDC says.

Researchers say these numbers could be explained by physiologic changes that occur during pregnancy, such as increased heart rate, higher oxygen consumption, decreased lung capacity, increased risk of blood clot formation and weakened immune systems.

And although Black women made up just 14% of the women included in the analysis, they made up about 27% of deaths among those who were pregnant and about 37% of deaths among those who were not pregnant. Meanwhile, Asian and Native Hawaiian/Pacific pregnant women were of particularly increased risk for ICU admission.

Younger pregnant women between 15 and 24 years old faced triple the risk of receiving invasive ventilation compared with nonpregnant women of the same age. “To minimize the risk for acquiring SARS-CoV-2 infection, pregnant women should limit unnecessary interactions with persons who might have been exposed to or are infected with SARS-CoV-2, including those within their household as much as possible,” the report reads.

“When going out or interacting with others, pregnant women should wear a mask, social distance, avoid persons who are not wearing a mask, and frequently wash their hands. In addition, pregnant women should take measures to ensure their general health, including staying up to date with annual influenza vaccination and prenatal care.”