Unexplained Infant Deaths Without Unsafe Sleep Factors: 2011 to 2020

Area of Science:

• Pediatrics
• Public Health
• Forensic Pathology

Background:

• Sudden unexpected infant death (SUID) remains a significant concern in public health.
• Understanding SUIDs occurring in safe sleep environments is critical for developing targeted prevention strategies.
• Previous research has highlighted various risk factors, but a detailed characterization of SUIDs within safe environments is needed.

Purpose of the Study:

• To describe sudden unexpected infant deaths (SUIDs) occurring in safe sleep environments.
• To explore differences in demographic, birth, environmental, medical, and death investigation characteristics among these SUIDs.
• To identify potential etiologies for SUIDs within safe sleep contexts.

Main Methods:

• Analysis of SUID data from 22 jurisdictions between 2011 and 2020.
• Classification of SUIDs as unexplained with no unsafe sleep factors (U-NUSF).
• Inclusion of infants who were witnessed to become unresponsive or found unresponsive after sleep in a safe environment.

Main Results:

• Most U-NUSF SUIDs (117 cases) occurred before 4 months of age.
• Witnessed deaths were more common in infants <1 month, while unwitnessed deaths peaked at 2-3 months.
• While most unwitnessed deaths occurred in cribs, witnessed deaths often happened while being held or in car seats; 46% had abnormal autopsy findings.

Conclusions:

• SUIDs in safe sleep environments represent a heterogeneous group of infants.
• Potential etiologies may include physiological, genetic, or environmental factors.
• Further research is needed to elucidate the specific causes and inform prevention efforts.