US premature births saw a slight decline in 2020 but experts say it's no cause for celebration

For the first time in six years, an annual report found the rate of babies born premature in the United States slightly decreased from 2019 to 2020.

But health experts say the marginal improvement is no cause for celebration.

Preterm birth rates in the U.S. decreased .1% from 10.2% in 2019 to 10.1% in 2020, according to the report published Monday by the March of Dimes, a nonprofit that works to improve the health of pregnant people and babies.

But the report also found Black and American Indian/Alaskan Native preterm births increased. The rate of Black preterm births increased from 14.25% in 2019 to 14.36% in 2020 and the American Indian/Alaskan Native preterm birth rate rose from 11.55% to 11.61%.

The rate of Black preterm births was about 50% higher than white or Hispanic pregnant people, which was 9.1% and 9.8%, respectively.

“It’s easy to get happy over this slight decrease in the overall preterm birth rate,” said Dr. Zsakeba Henderson, Chief Medical Officer of March of Dimes. “But the groups that have been most disproportionately affected, not only did they not have a decrease, they had an increase.”

Since, 2014, the rate of Black preterm births has increased 7.8%; the rate among American Indian/Alaskan Natives has risen 11.1%, according to the report. Although preterm birth rates among Hispanics dropped 1.4% from 2019 to 2020, they’ve seen an 8.2% increase since 2014.

A preterm birth is when a baby is born before the 37 weeks of pregnancy has been completed, according to the Centers for Disease Control and Prevention. In 2020, preterm births affected 1 out of every 10 infants born in the U.S. 

Babies born too early, especially before 32 weeks, have higher rates of death and disability including breathing problems, feeding difficulties, cerebral palsy, developmental delay, vision problems and hearing problems, according to the CDC. In 2019, preterm birth and low birth weight accounted for about 17% of infant deaths before one year of age.

The March of Dimes has released its annual Report Card since 2008. According to the organization’s scoring criteria, an “A” is a preterm birth rate of 7.7% or less and an “F” is a rate of 11.5% or more.

Overall, the U.S. earned a “C-“ for its 10.1% preterm birth rate.

“The report card for the first time in six years has shown a slight decline but the grade that we assigned the country is still a C-,” said Stacey D. Stewart, March of Dimes CEO  and president.  “A decline from 10.2 to 10.1 isn’t really a celebration.”

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The report card also showed preterm birth rates worsened in 13 states, with Alabama, Arkansas, Louisiana, Mississippi, South Carolina, West Virginia and Puerto Rico earning an “F.” Only one state – Vermont – earned an “A.”

Researchers found a slight improvement in about 33 states, Stewart said, but many remain far from the 8.1% goal set by the March of Dimes in 2008.

“It’s an ambitious goal but … it’s an achievable goal,” she said. “We are one of the wealthiest countries in the world, why are we achieving one of the worst outcomes in the world in terms of moms and babies?”  

After Vermont, 12 states earned a “B+” through “B-,” 18 states earned a “C+” through “C-,” and 12 states earned a “D+” through “D-.” The wide range of preterm birth rates between states tells health experts there isn't one solution to the problem. 

“There’s not a lot of biologic reason that I can think about within the U.S. on why we have such profound differences across states,” Dr. Emily Miller, assistant professor of maternal-fetal medicine at Northwestern University Feinberg School of Medicine and chief of obstetrics at Northwestern Medicine, who was not affiliated with the report. “So that reflects differences some of our policies or unequal access to quality care across the states.”

The report card also added three new measurement tools examining factors that contribute to the health of infants and pregnant people: low-risk Cesarean births, social vulnerability index, and midwifery and doula care legislation and policies.

According to the report, the U.S. low-risk C-section rate in 2020 was 25.6%. Since 1985, the World Health Organization has considered the ideal rate for C-section births to be between 10% to 15%. 

The March of Dimes defines a low-risk C-section as one that occurs at 37 weeks or more of pregnancy, involving a single baby positioned headfirst. 

“We focus on low-risk because those are the ones that we expected to be uncomplicated and not be delivered by surgery,” Henderson said. “The rates of C-section births have increased dramatically in the U.S. and we know it has contributed to morbidity, illness and pregnancy complications.”

An observational study published in the peer-reviewed journal CMAJ in 2019 found women who had C-sections were 80% more likely to have complications than those who delivered vaginally. Women over the age of 35 who had C-sections were almost three times more likely to have severe complications.

The March of Dimes also included a social vulnerability index at the county level that included socioeconomic status, household composition and disability, minority status and language, housing type and transportation.

“Mapping social vulnerability across the United States and comparing that map with their map of preterm birth rates teaches us a lesson,” Miller said. “We need to parlay that lesson into action by focusing on mitigation of some of the pathways that go from social vulnerability to preterm birth.”

The COVID-19 pandemic has exposed and exacerbated these social vulnerabilities, health experts say, and they must be addressed to reduce preterm birth rates. 

"That's especially true for women before pregnancy, during pregnancy and after pregnancy," Stewart said. 

Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT. 

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