Racial differences in the impact of maternal smoking on sudden unexpected infant death

Background Prenatal smoking increases the risk of Sudden Unexpected Infant Death (SUID). Whether exposure patterns and associations differ by race requires further study. Objectives Determine if patterns of exposure and associations between SUID and maternal smoking before and during pregnancy differ by race. Methods Using U.S. National Center for Health Statistics linked birth/infant death files 2012–2013, we documented SUID by smoking duration and race. Maternal smoking history: never, pre-pregnancy only, and pre-pregnancy plus first, first, second, or all trimesters. Results Smoking was more common in non-Hispanic White (NHW) than non-Hispanic Black (NHB) mothers and more evident for both in SUID cases. The most common exposure duration is from before and throughout pregnancy (SUID: 78.3% NHW, 66.9% NHB; Survivors: 60.22% and 53.96%, respectively). NHB vs. NHW SUID rates per 1000 live births were 1.07 vs. 0.34 for non-smokers and 3.06 and 1.79 for smokers, ORs trended upward for both with increasing smoking duration. Conclusion Fewer NHB mothers smoked, but both NHB and NHW groups exhibited a dose-response relationship between smoking duration and SUID. The most common duration was from before to the end of pregnancy, suggesting difficulty in quitting and a need for effective interventions.