Characteristics of Sudden Unexpected Infant Deaths on Shared and Nonshared Sleep Surfaces.

Objectives: Describe characteristics of sudden unexpected infant deaths (SUID) occurring on shared or nonshared sleep surfaces.

Methods: We examined SUID among residents of 23 US jurisdictions who died during 2011 to 2020. We calculated frequencies and percentages of demographic, sleep environment, and other characteristics by sleep surface sharing status and reported differences of at least 5% between surface sharing and nonsharing infants.

Results: Of 7595 SUID cases, 59.5% were sleep surface sharing when they died. Compared with nonsharing infants, sharing infants were more often aged 0 to 3 months, non-Hispanic Black, publicly insured, found supine, found in an adult bed or chair/couch, had a higher number of unsafe sleep factors present, were exposed to maternal cigarette smoking prenatally, were supervised by a parent at the time of death, or had a supervisor who was impaired by drugs or alcohol at the time of death. At least 76% of all SUID had multiple unsafe sleep factors present. Among surface-sharing SUID, most were sharing with adults only (68.2%), in an adult bed (75.9%), and with 1 other person (51.6%). Surface sharing was more common among multiples than singletons.

Conclusions: Among SUID, surface sharing and nonsharing infants varied by age at death, race and ethnicity, insurance type, presence of unsafe sleep factors, prenatal smoke exposure, and supervisor impairment. Most SUID, regardless of sleep location, had multiple unsafe sleep factors present, demonstrating the need for comprehensive safe sleep counseling for every family at every encounter.