Maternal mortality rates increased during 1st year of COVID pandemic: CDC

Maternal mortality rates in the U.S. rose during the first year of the COVID-19 pandemic and racial disparities that existed before the pandemic were perpetuated, according to a new report published Wednesday by the Centers for Disease Control and Prevention.

The report looked at data from the CDC's National Centers for Health Statistics and compared 2020 rates to rates in 2018 and 2019.

Maternal deaths were defined as women who died either while pregnant or within 42 days of the end of pregnancy.

In 2020, 861 women in the U.S. died of maternal causes -- a rate of 23.8 per 100,000 live births, the report found.

This is an increase of 14% from the 754 deaths that occurred in 2019 and up 30% from the 658 deaths that occurred in 2018. In 2019, the rate was 20.1 deaths per 100,000 and even lower in 2018 at 17.4 per 100,000.

The reasons for the increase during the first year of the pandemic were not stated in the report, although the author said the virus likely played a role.

Racial disparities continue

There were large disparities when it came to race and ethnicity. The report found that Black women died of maternal causes at nearly three times the rate of white women, up from around 2.5 times higher than in 2019.

The rate for Black women was 55.3 deaths per 100,000 in 2020 and the rate for white women was 19.1 deaths per 100,000. For black women, the rate increased nearly 26% from the year prior.

Black women also died at higher rates than Hispanic women, who had a rate of 18.2 deaths per 100,000 births in 2020 -- a more than 40% increase from the previous year.

What's more, increases from 2019 to 2020 among Black women and Hispanic women were statistically significant while the increase over the same time period for white women was not viewed as significant, the report said.

The report also looked at maternal mortality rates by age and found that the rates increased as women's ages did.

The lowest rate was for women under age 25 at 13.8 deaths per 100,000 live births and the highest rate was for women aged 40 and over at 107.9 per 100,000 births, about 7.8 times higher. Older mothers also experienced an increase in mortality that was statistically significant, according to the CDC.

Several studies have found that women who become pregnant after age 35 are considered "high-risk" because they are at an increased risk for complications impacting either the baby or mom including premature birth, excessive bleeding during birth and eclampsia..

Dr. Donna Hoyert, a health scientist in the NCHS's Division of Vital Statistics and author of the report, said this is likely one of the reasons for the higher mortality rates among older women.

"That and there are a smaller number of individuals who are at the end of reproductive ages, so the statistics become much more variable from year to year," she told ABC News.

COVID-19 'likely' contributed to rise

The report did not offer theories for why maternal mortality rates rose in 2020, the first year of the COVID-19 pandemic.

However, previous studies have shown that pregnant women are at increased risk of severe complications and death from COVID compared to the general population.

It could also help explain the higher rates among Black women, with Black Americans more likely to suffer from severe effects of the virus than the white population.

"​​Yes, the pandemic likely contributed to the increase from 2019 to 2020 and beyond that," Hoyert said. "As the pandemic plays out, we want to see how it affects overall mortality rates and our trend of comparable data over time."

She continued, "There's been other studies that have come out further documenting continuing morality from COVID-19 and excess mortality associated with that, so it will be something to look into."