SUID drives widening Black-White infant mortality gap since 2020

After nearly 2 decades of narrowing, the mortality gap between infants born to non-Hispanic Black mothers and those born to non-Hispanic White mothers has widened since 2020, and sudden unexpected infant death (SUID) is the leading cause-specific driver, according to a cross-sectional analysis published in JAMA Network Open.¹

The findings suggest that preterm birth, long viewed as the main explanation for the disparity, accounts for a shrinking share of it. Co-author Leslie Root, a demographer and assistant research professor in the Institute of Behavioral Science at the University of Colorado Boulder, described the data as evidence of "an acute crisis right now in sudden unexplained infant death," a category many assumed had been brought under control.²

Kitagawa decomposition of the Black-White infant mortality gap

Investigators analyzed National Center for Health Statistics linked birth/infant death records from 2003 through 2024, covering 57,870,726 live births and 366,384 infant deaths (141,651 among infants of Black mothers; 224,733 among infants of White mothers).¹ Using the Kitagawa method, they divided the gap into a composition effect, reflecting differences in gestational age distribution across 7 categories, and a rate effect, reflecting differences in mortality among infants born at the same gestational age, overall and across 13 cause-of-death categories.¹

Infant mortality rate trends and the rising rate effect

From 2003 to 2024, the Black infant mortality rate (IMR) declined from 13.2 to 10.7 deaths per 1000 live births and the White IMR from 5.6 to 4.3.¹ The absolute gap narrowed from 7.7 to 6.0 deaths per 1000 live births between 2003 and 2019, then rose to 6.4 (95% CI, 6.1-6.8) by 2024 as Black infant mortality increased while White infant mortality continued to decline.¹

Gestational age composition accounted for most of the gap in every year studied. Preterm birth (<37 weeks) occurred in 16.9% of births to Black mothers vs 10.5% of births to White mothers, and infants born before 28 weeks alone accounted for more than half the gap.¹ However, the rate effect grew from 21% (95% CI, 18%-24%) of the gap in 2003 to 32% (95% CI, 28%-35%) in 2024.¹

SUID as the largest cause-specific contributor to the disparity

In 2024, SUID was the largest single contributor to the gap at 1.56 (95% CI, 1.42-1.71) deaths per 1000 live births, roughly one-quarter of the total, and 92% of that contribution reflected the rate effect rather than differences in gestational age.¹ Short gestation or low birth weight ranked second at 1.44 deaths per 1000 live births, driven primarily by composition.¹

From 2020 to 2024, the SUID rate effect rose from 1.26 to 1.44 deaths per 1000 live births, and SUID accounted for 35% of the net increase in the gap, the largest of any cause.¹ Within the SUID category, ill-defined or unspecified deaths increased most, although sudden infant death syndrome and accidental suffocation and strangulation in bed have also risen since 2015.¹

Possible explanations: COVID-19, respiratory viruses, and opioids

The authors noted that the increase coincided with the COVID-19 pandemic and paralleled racially disparate increases in maternal mortality during the same period.¹ Root also cited off-season respiratory virus resurgences, lingering socioeconomic effects of the pandemic, and rising opioid overdose deaths among Black Americans; the team plans to study parental opioid use next.² None of these hypotheses were tested here.

SUID burden and safe sleep counseling in pediatric practice

Approximately 3400 US infants die of SUID each year.³ The American Academy of Pediatrics recommends placing infants on their backs for every sleep on a firm, flat, noninclined surface, room-sharing without bed-sharing, keeping soft bedding out of the sleep space, supporting breastfeeding, and avoiding prenatal and postnatal exposure to smoke, alcohol, and opioids.⁴ Root said progress from earlier back-to-sleep and crib safety campaigns makes the current reversal especially alarming.²

Limitations of the infant mortality decomposition

The analysis included only non-Hispanic Black and non-Hispanic White mothers, although SUID rates are also high among American Indian and Alaska Native infants and infants of multiracial mothers.¹ The Kitagawa method assumes additive effects, cause-of-death coding may vary in accuracy across populations, and changes in maternal age, parity, and education were not assessed.¹ As a cross-sectional study, it cannot establish why SUID disparities have grown.

References:

1. Alexander MJ, Alexander R, Root L. Decomposition of Black and White infant mortality rates. JAMA Netw Open. 2026;9(9):e2635321. doi:10.1001/jamanetworkopen.2026.35321
2. Marshall L. Sudden, unexpected deaths on rise among infants born to Black mothers. News release. University of Colorado Boulder. October 5, 2026. Accessed October 12, 2026. https://www.newswise.com/articles/sudden-unexpected-deaths-on-rise-among-infants-born-to-black-mothers
3. Erck Lambert AB, et al. Characteristics of sudden unexpected infant deaths — United States, 2020–2024. MMWR Morb Mortal Wkly Rep. 2026;75(35). Accessed October 12, 2026. https://www.cdc.gov/mmwr/volumes/75/wr/mm7535a1.htm
4. Moon RY, Carlin RF, Hand I; Task Force on Sudden Infant Death Syndrome; Committee on Fetus and Newborn. Sleep-related infant deaths: updated 2022 recommendations for reducing infant deaths in the sleep environment. Pediatrics. 2022;150(1):e2022057990. doi:10.1542/peds.2022-057990