The U.S. preterm birth rate increased from 10.1% in 2020 to 10.5% in 2021, the worst recorded since 2007, according to a report from the March of Dimes.
The increase follows a slight decrease in the preterm birth rate from 2019 to 2020 and led to a drop in the U.S. Report Card grade from a C- to a D+.
The report grades U.S. states, the District of Columbia, Puerto Rico and 100 cities on infant and maternal health. Overall, 45 states, Washington, D.C., and Puerto Rico experienced an increase in preterm birth rates, while four states saw a decrease.
Latest data on the infant mortality rate show a slight decline from 5.6 deaths per 1,000 live births in 2019 to 5.4 deaths per 1,000 live births in 2020. Overall, 30 states had an improved infant mortality rate, 13 states stayed the same and eight states worsened.
The report shows racial differences in birth outcomes persist throughout the country. U.S. infants born to Black and Native American moms are 62% more likely to be born before 37 completed weeks of gestation than those of White women. The preterm birth rate among Black women is 52% higher than the rate among all other women.
While babies born to Asian/Pacific Islander moms generally have the lowest preterm birth rate, it increased from 8.7% in 2020 to 9.5% in 2021, the largest increase of all racial and ethnic groups.
Vermont was the lone state to receive an A rating, which means a preterm birth rate of less than or equal to 7.7%. California, Idaho, Massachusetts, New Hampshire, New Jersey, Oregon and Washington received a B-, B or B+ rating (a preterm birth rate between 8.2% and 9.2%).
States and territories receiving an F (preterm birth rate of 11.5% or higher) include Alabama, Arkansas, Georgia, Kentucky, Louisiana, Mississippi, Oklahoma, South Carolina, West Virginia and Puerto Rico.