The number of women in the United States who died during pregnancy or shortly after giving birth increased sharply during the first year of the coronavirus pandemic, according to a new study, an increase that health officials attribute partly to Covid and pandemic-related disruptions.

The new report, from the National Center for Health Statistics, found that the number of maternal deaths rose 14 percent, to 861 in 2020 from 754 in 2019.

The United States already has a much higher maternal mortality rate than other developed countries, and the increase in deaths pushes the nation’s maternal mortality rate to 23.8 deaths per 100,000 live births in 2020 from 20.1 deaths in 2019. Maternal mortality rates in developed countries have in recent years ranged from fewer than two deaths per 100,000 live births in Norway and New Zealand to just below nine deaths per 100,000 live births in France and Canada.

Black women in America experienced the most deaths: One-third of the pregnant women and new mothers who died in 2020 were Black, though Black Americans make up just over 13 percent of the population. Their mortality rate was nearly three times that of white women.

The mortality rate for Hispanic women, which has historically been lower than for white women, also increased significantly in 2020 and is now almost on par with the rate for white women. Death rates increased among all pregnant women older than 24, but particularly in those 40 and over, whose mortality rate was nearly eight times that of women younger than 25.

Although the new report is sparse on details — no maternal mortality figures were provided for American Indian/Alaska Native women, who have higher pregnancy-related deaths than white, Hispanic and Asian/Pacific Islander women — experts said some of the deaths were most likely related to the coronavirus pandemic. Pregnancy puts women at risk for more severe disease if they are infected with the SARS-CoV-2 virus, which causes Covid, and vaccines were not available for them in 2020.