Three decades of steady progress in reducing US infant mortality mask a troubling and growing divide: While overall national rates continue to hit historic lows, a surge in sudden unexpected infant deaths (SUID) among Black infants has reversed years of narrowing racial disparities.

The US infant mortality rate dropped from 7.57 deaths per 1000 live births in 1995 to 5.52 deaths per 1000 in 2024. Preliminary data from the CDC for 2025 show the trend continued, reaching a record low of 5.39 deaths per 1000.

Despite the national gains, a racial divide widened.

Between 2003 and 2019, racial differences in mortality narrowed from 7.7 to 6 deaths per 1000 live births, according to the findings of a new study published in Jama Network Open. However, in 2020, the gap began to rise again, reaching 6.4 more deaths per 1000 among Black children in 2024.

Researchers say the divide occurred even as fewer White infants died.

“This is a large, persistent gap that is recognized as a major public health issue in the United States,” said Leslie Root, PhD, assistant research professor at the Institute of Behavioral Science at the University of Colorado Boulder, who helped lead the study.

Root and colleagues analyzed data from more than 366,000 infant deaths from 2003 through 2024, which included 141,651 deaths among Black infants and 244,733 among White infants.

Premature birth remained the single largest factor contributing to the mortality gap between Black and White infants. Nearly 15% vs 9.4% of babies born to Black mothers vs White mothers are premature, according to a December KFF analysis.

Babies born under 28 weeks accounted for more than two thirds of the mortality gap in 2003 but dipped to just more than half of the difference in 2024.

The JAMA Network Open study identified a new and troubling trend: higher rates of mortality among Black infants who were at the same gestational age as their White counterparts.

The findings suggest higher rates of Black infant mortality would persist, even if disparities in preterm birth were eliminated.

“The prematurity gap has lessened somewhat over time, but differences in mortality risk when holding gestational age constant are increasing, especially after 2020,” Root said.

SUID was the single largest cause of the widening gap after 2020. These include deaths from sudden infant death syndrome, accidental suffocation or strangulation in bed, and unexplained causes.

“The increase in SUID rates and disparities tells the story that prematurity is not the only cause,” said Tonia Branche, MD, neonatologist at the Ann & Robert H. Lurie Children’s Hospital of Chicago in Chicago, who was not involved with the study.

A baby tends to have the highest risk for sleep suffocation in the first 4 months of life, when they are less able to reliably lift or reposition themselves, Branche said.

She often guides parents to follow the standard “ABCs” of safe sleep, which recommend that a baby sleeps alone, always on their back, and in a crib or bassinet that is clear of blankets, pillows, or other items that could obstruct breathing.

Thirdhand smoke is also a risk factor. She suggests caregivers and anyone holding the infant to change their clothes to reduce exposure to lingering smoke residue.

“Having these added measures and making sure that the environment is as safe as it can reduce some of the risk,” Branche said.

Another factor that may contribute to increasing disparities after the pandemic is larger the growth of structural inequalities, including unequal access to high-quality prenatal and pediatric care. Maternal and pediatric care centers in economically vulnerable communities are also more likely to temporarily or permanently close.

To address some of these disparities, pregnant patients at Ann & Robert H. Lurie Children’s Hospital of Chicago are provided additional services to address their nonmedical needs, such as mental health counseling and home visits.

Root said the findings show that improving healthcare access alone will not be enough to close the gap.

“Healthcare providers definitely have a role in addressing mortality disparities — better care will lead to better outcomes,” she said. “The focus is often placed on obstetrics, gynecology, and to some extent pediatrics, but this study points to the need for systemic solutions that support the health and well-being of Black women and their children across the life course.”

The study authors reported no relevant financial interests.

Steven Ross Johnson is a journalist who covers public health and healthcare delivery issues.