COVID-19 Pandemic-Era Changes in Sudden Unexpected Infant Death in the United States

OBJECTIVE
We aimed to investigate COVID-19 pandemic-era changes in postperinatal sudden unexpected infant death (SUID) and their association with maternal sociodemographic factors.

METHODS
We conducted a nationwide cohort study using Centers for Disease Control and Prevention National Center for Health Statistics data for US births from 2016 to 2021. SUID cases were identified using International Classification of Diseases, Tenth Edition codes R95, R99, and W75; we defined pandemic-era births as those between April 2020 and December 2021. We compared postperinatal SUID rates before and during the pandemic and conducted counterfactual analyses to identify whether the pandemic was associated with changes in SUID rate trends. Analyses were stratified by maternal race and ethnicity, age, education, and insurance status.

RESULTS
Overall postperinatal SUID rates increased from 87.6 per 100 000 births prepandemic to 95.3 after pandemic onset (rate difference, 7.7; 95% CI, 4.9–10.5). Significant rate increases were found among infants born to non-Hispanic Black mothers, younger mothers, mothers with lower educational attainment, and Medicaid recipients. Counterfactual analyses showed higher than expected pandemic-era rates for these groups and additionally infants born to non-Hispanic white mothers and mothers with private insurance. Only 0.86% of pandemic-era SUID cases included COVID-19 as an additional cause of death.

CONCLUSION
Postperinatal SUID rates increased after the onset of the COVID-19 pandemic, with the largest increases in sociodemographic groups already at high risk for SUID. Secondary effects of the pandemic, rather than direct viral impact, may have contributed to the rise in SUID rates. The study underscores the need for further research to pinpoint specific factors and develop interventions to mitigate these increases.