Dose–response association between maternal smoking during pregnancy and the risk of infant death: a nationwide, population-based, retrospective cohort studyResearch in context

Summary: Background: Association of timing and intensity of maternal smoking during pregnancy with all-cause and cause-specific infant death remains inconclusive. We aimed to examine the dose–response association of maternal smoking during each of the three trimesters of pregnancy with all-cause and cause-specific infant death. Methods: In this nationwide, population-based, retrospective cohort study, data were extracted from the U.S. National Vital Statistics System, 2015–2019. We included mother–infant pairs after excluding twin or multiple births, newborns with gestation age <37 weeks and those with low birthweight, mothers aged