Layered risk factors for sudden unexpected infant death

Sudden Unexpected Infant Death occurs about once a week in Cook County, Illinois, the second largest county in the United States, where SUID disproportionately affects families from high hardship communities. The Cook County SUID Case Registry was established in 2019 to collect, analyze, and disseminate data to advance SUID prevention.

Cook County SUID Case Registry data from 2019 to 2023 were analyzed for descriptive characteristics including infant age, race, ethnicity, gestational age, birth weight, maternal age, prenatal/household smoke exposure, and sleep environment hazards. Case reviews (including narrative review) identified patterns of risk which were quantified to provide proportions of SUID that occurred among families with histories of domestic violence, substance use, and among families whose infant died when they were away from their usual home ("temporary stays"). SUID that occurred among preterm infants during temporary stays were further analyzed to detail risk among this population.

From 2019 to 2023, 208 sleep-related infant deaths occurred in Cook County, Illinois. These deaths peaked at 1-2 months of age. The rate among non-Hispanic Black and Hispanic infants was 14 and 2.3 times that of white infants respectively. Most sleep-related infant deaths involved unsafe sleep situations including a sleep surface other than a crib/bassinet [175/208 (84%)], surface sharing [135/206 (66%)], and soft bedding in the sleep environment [190/205 (93%)]. Families whose infants died experienced social challenges including histories of domestic violence [32/182 (18%)], maternal substance use [53/185 (29%)] and temporary stays outside of the usual home [34/208 (16%)]. Preterm infants who died during temporary stays [12/34 (35%)] had multiple sleep environment hazards [non-supine sleep (4/12, 33%), non-approved sleep surface (12/12,100%), surface sharing (10/11, 91%), soft bedding (12/12,100%)] and social challenges [histories of domestic violence (3/12, 25%), maternal substance use (5/12, 42%) and child welfare involvement (9/12, 75%)].

SUID in Cook County is closely tied to complex social issues and high hardship resulting in layered risk for vulnerable infants. Future work is needed to better understand how these challenges translate into unsafe sleep situations. Preventing SUID connected to these issues necessitates approaches that engage and equip families alongside trusted partners within communities most impacted by sleep-related infant death.