Sudden unexpected infant death is increasing, new study finds | Image Credit: © Children's Hospital of Richmond - © Children's Hospital of Richmond - stock.adobe.com.

Rates of sudden unexplained infant death (SUID) in the United States have increased in recent years, with disparities present. According to new research published in JAMA Pediatrics from researchers at Virginia Commonwealth University, research that included newer data from 2020 to 2022, the rise in SUID is more generalized and increased in infants across multiple races and ethnic backgrounds. Despite the overall increase, increased disparities exist.^1,2

These trends were observed while overall infant mortality decreased.¹

Study details and results

In a cross-sectional study, investigators used infant mortality rates from CDC WONDER, which included 1999-2017 bridged-race data and 2018-2022 single-race data. The top 13 causes of infant death from January 1, 2018, to December 31, 2022, and substituted sudden infant death syndrome with the more inclusive SUID.¹

"Race (non-Hispanic American Indian or Alaska Native, Asian, Black, Native Hawaiian or Other Pacific Islander, and White) and Hispanic ethnicity were reported by next of kin or if unavailable, by the funeral director," stated the study authors.

According to results, overall infant mortality decreased by 24.2% from 1999 to 2022, from 736 to 558 per 100,000. The largest decline occurred from 2007 to 2011 (–3.6%). Analyses revealed recent decreases in mortality for many causes of death, with the exception of SUID.

SUID increased from 89.9 to 100.5 per 100,000 from 2020 to 2022.

"Although a prior CDC study – using data until 2020 – found that Sudden Unexpected Infant Death was increasing for Black infants, this new study – adding data from 2021 and 2022 – found that the rise is more generalized and occurred in infants overall,” said Elizabeth Wolf, M.D., associate professor in VCU School of Medicine’s Department of Pediatrics, pediatrician at Children’s Hospital of Richmond at VCU and lead author on the study.²

Study results demonstrated that mortality rates were 2 to 4 times higher among Black infants than White infants for all causes of death other than congenital malformations and hemorrhage. The rate ratios for Black vs Asian infants were 10.7 (95% CI, 9.3-12.3) for SUID, 4.6 (95% CI, 3.3-6.8) for unintentional injuries, and 4.2 (95% CI, 3.0-5.9) for hypoxia and birth asphyxia.¹

Related: Advocating and community involvement to decrease SUID

Mortality rates for American Indian and Alaska Native infants were significantly higher, compared with Asian infants, for SUID (rate ratio, 9.6; 95% CI, 8.0-11.5), unintentional injuries (rate ratio, 5.5; 95% CI, 3.2-9.3), and necrotizing enterocolitis (rate ratio, 2.8; 95% CI, 1.6-4.7).

The study authors noted that the included data from 2021 and 2022 revealed a more generalized increase in SUID rates across multiple races, and stated possible explanations include COVID-19 or other respiratory illnesses, maternal opioid use, and social media's influence on infant sleeping practices.

“In social media posts, infants can be seen in unsafe sleep positions, for example on their stomach instead of on their back, and in unsafe sleep environments such as adult beds, couches and baby swings," Wolf added in a statement.²

While SUID mortality is up across multiple racial and ethnic groups, the rate for Black infants is 10 times higher compared to Asian infants, and 3 times higher than White infants.

According to a press release, the authors suggested these disparities could be the result of unsafe sleep position, prematurity, tobacco exposure and/or infant feeding. They noted further research is needed to explore these potential causes.

Conclusion

Wolf and co-authors of the study placed emphasis on safe sleep education at well-child visits between patients and families, and sees opportunities to strengthen public health messaging on the importance of safe sleep. She also calls for tightened regulations surrounding unsafe or misleading infant product and devices.

"An infant dying from SUID is a horrific tragedy and causes incomprehensible trauma to the family," said Wolf. "Although not all SUID is preventable, there are some ways to reduce an infant’s risk."

Reference:

1. Wolf ER, Rivara FP, Sen A, Woolf ST. Sudden Unexpected Infant Death and Disparities in Infant Mortality in the US, 1999-2022. JAMA Pediatrics. January 27, 2025. doi:10.1001/jamapediatrics.2024.6200

2. Infant mortality rates declining, but Sudden Unexpected Infant Death is on the rise. Virginia Commonwealth University. Press release. January 27, 2025. Accessed January 27, 2025. https://www.eurekalert.org/news-releases/1071511