By Kate Marino

Infant mortality in the United States decreased by 24.2% between 1999 and 2022. Researchers from Virginia Commonwealth University and Children’s Hospital of Richmond at VCU discovered this improvement in a study published Jan. 27 in the Journal of the American Medical Association Pediatrics. In the same study, however, they found mortality rates from Sudden Unexpected Infant Death (SUID) rose significantly – by 11.8% – 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.

Steven Woolf, M.D., director emeritus of the VCU Center on Society and Health and professor in VCU School of Medicine’s Department of Family Medicine, and Anabeel Sen, M.B.B.S., student in Epidemiology in VCU School of Public Health’s Department of Epidemiology, were among the other study authors, along with Frederick Rivara, M.D., of University of Washington’s Department of Pediatrics and Seattle Children’s Research Institute.

What is behind the rise in SUID?

Wolf attributes declining overall infant mortality rates to improved screening and treatment for illnesses affecting pregnant people, better obstetric management and neonatal care. Causes for the increase in SUID are harder to pinpoint. Possible explanations identified in this study include the rise of COVID-19 and other respiratory viruses, parental opioid use and the effect of social media on infant sleep 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.

This information builds upon a child mortality study the same group of researchers published in May 2024, which showed racial and ethnic disparities among youth, ages 1 to 19, were greatest in the category of injuries. This new research finds large disparities in many causes of infant death as well, especially SUID.

While SUID mortality rates are up across all racial and ethnic groups, the rate for Black infants is 10 times higher compared to Asian infants and three times higher than white infants. The authors suggest these disparities could reflect unsafe sleep position, prematurity, tobacco exposure and/or infant feeding, but further research is needed.

Where we go from here

As a pediatrician at Children’s Hospital of Richmond at VCU, Wolf places an emphasis on safe sleep education at well-child visits with her patients and families. She also sees opportunities to strengthen public health messaging on the importance of safe sleep and tighten regulations around unsafe or misleading infant products.

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

Efforts to support breastfeeding such as lactation support and paid parental leave could help lower risks of SUID. Expanding health insurance access and providing doulas to support mothers pre- and postnatally could also reduce infant mortality. Wolf also emphasizes that infants should receive all recommended vaccines on time to reduce their risks of serious infection.