A new study in JAMA Network Open reveals that sudden unexpected infant deaths (SUID) are climbing once more, particularly among babies of Black mothers, after years of steady decline. The research clarifies why the persistent racial divide in infant mortality, long a stubborn public health issue, began to grow wider after 2020.
Leslie Root, a demographer and one of the study’s authors, described the reversal as an “acute crisis”. Although infant mortality rates for Black mothers still sit roughly double those for white mothers, the gap has now reversed earlier improvements. The team examined federal records covering nearly 58 million live births between 2003 and 2024, identifying 366,384 infant deaths linked to Black mothers and 224,733 among white mothers.
The researchers broke down mortality rates across seven gestational age groups and 13 causes of death. Their analysis showed that while preterm birth remains a major driver of disparities, SUID, including sudden infant death syndrome (SIDS) and accidental suffocation, now represents over a third of the widening racial gap. This makes it the single largest factor in the reversal.
“This finding suggests that even if preterm birth disparities were eliminated entirely, a large mortality gap would remain, and sudden unexpected infant death is what is driving the increase,” said Root.
Unlike preterm birth, which has received sustained public health attention, SUID rates have surged among Black infants since 2020 while remaining stable for white infants. The timing coincides with the COVID-19 pandemic, which may have played a role. Recent evidence suggests off-season respiratory infections, such as COVID-19, RSV, and influenza, could heighten vulnerability to SUID in infants. The pandemic’s broader social and economic disruptions may have further deepened existing inequities.
Another possible explanation is the recent rise in opioid-related deaths among Black Americans, which now exceed white rates for the first time. Root pointed out that parental opioid use raises SUID risk, and future investigations will explore whether this link helps explain the trend.
The study did not cover Native American or Alaska Native populations, leaving questions about how disparities might affect those groups. The findings confirm that SUID remains a leading cause of infant death in the U.S., with roughly 3,400 unexpected deaths occurring annually.