Professor Rutgers, Robert Wood Johnson Medical School New Brunswick, New Jersey, United States
Background: SUID risk in bed-sharing is reported to rise with duration (AAP 2022). However, there is limited information on duration of last sleep (DLP), from placement to discovery, and if it is modified by bed-sharing, sleep position, and race. With limited recent improvement in reducing rates of SUID or racial disparities, examination of novel risk factors is warranted. Objective: The goal of the study was to examine the duration of last sleep with respect to sleep position, bed sharing, and race. Design/Methods: We conducted a retrospective analysis of DLP in finalized SUID cases reported to the SIDS Center of New Jersey for the 2011-2019 period; 96 cases met these criteria: over 36 weeks gestational age, deaths from zero to 4 months, and DLP less than 7 hours. We evaluated duration, sleep position, bed-sharing, and race. Results: No differences in DLP were found between deaths in the first two (n=63) vs. the second two (n=33) months of life (3.57+/-2.06 hours vs. 3.21+/-2.07 hours, p=0.42), and they were combined for analysis. DLP was longer with bedsharing (n=53) vs. none (n=42)(4.19+/-1.83 hours vs. 2.49+/-1.98 hours, p= < 0.0001). There were no differences in DLP whether sharing occurred with the mother (n=43) or other family member (n=10) (4.07+/-1.65 hours vs. 4.35+/-2.42, p=.66). Forty-three percent of White non-Hispanic (WNH) vs. 59% of Black non-Hispanic (BNH) mothers shared (p=0.23). Sharing with any partner occurred in 45% of WNH and 63% of BNH cases, p=0.16. Infants of WNH mothers who shared (n=9) had a comparable DLP to infants not sharing (n=12) (2.87+/-1.78 hours vs. 2.46+/-1.39 hours, p=0.56). However, infants of BNH mothers who shared (n=27) had a longer DLP than infants not sharing (n=19) (4.30+/-1.47 hours vs. 2.89+/-2.42 hours, p=0.02.) This racial pattern was also found when comparing sharing with any partner vs. no sharing. Supine position at discovery was found in 100% of WNH and 50% of BNH cases that shared p=0.03. Bedsharing infants' DLP was longer with prone (n=18) vs. supine position at discovery (n=31) (5.08+/-1.83 hours vs. 3.98+/-1.58 hours, p=0.03).
Conclusion(s): In contrast to a study in living infants (Massare, 2023) that found decreased sleep duration when bed-sharing, we found the duration from placement to discovery of a SUID case was longer with bed-sharing and specific to BNH cases. Prone position, more commonly found in BNH cases, further increased duration. We speculate that adult arousal and strength of infant signals may be diminished in bed sharing when coupled with prone sleep and may account for the elevated risk in this environment.
