Changes in Sleep Position During Infancy

Abstract

Context.— Prone sleeping by infants has been associated with an increased risk of sudden infant death syndrome. Objective.— To document the prevalence of and identify risk factors for prone sleeping during the first 6 months of life. Design.— Prospective cohort study. Setting.— Eastern Massachusetts and northwest Ohio. Study Participants.— A total of 7796 mothers of infants weighing 2500 g or more at birth. Main Outcome Measures.— Maternal and infant characteristics related to prone sleeping at 1 month and 3 months of age. Results.— Between 1 month and 3 months of age, prone sleeping increased from 18% to 29%. At 1 month, prone sleeping was associated with the following maternal characteristics: non-Hispanic black or Hispanic race/ethnicity, younger age, less education, and higher parity. At 3 months, switching from nonprone to prone position was associated with mother's race/ethnicity of non-Hispanic black (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.2-2.3) or Hispanic (OR, 1.5; 95% CI, 1.1-2.2); younger maternal age (compared with mothers >34 years: 18-24 years, OR, 1.6; 95% CI, 1.2-2.2; Conclusions.— If infant sleeping practices in the study communities are representative of practices throughout the United States, a substantial number of infants who slept nonprone at 1 month sleep prone at 3 months.