title: Swaddling and the Risk of Sudden Infant Death Syndrome: A Meta-analysis.
abstract: Swaddling is a traditional practice of wrapping infants to promote calming and sleep. Although the benefits and risks of swaddling in general have been studied, the practice in relation to sudden infant death syndrome remains unclear.
  
  
  
  The goal of this study was to conduct an individual-level meta-analysis of sudden infant death syndrome risk for infants swaddled for sleep.
  
  
  
  Additional data on sleeping position and age were provided by authors of included studies.
  
  
  
  Observational studies that measured swaddling for the last or reference sleep were included.
  
  
  
  Of 283 articles screened, 4 studies met the inclusion criteria.
  
  
  
  There was significant heterogeneity among studies (I(2) = 65.5%; P = .03), and a random effects model was therefore used for analysis. The overall age-adjusted pooled odds ratio (OR) for swaddling in all 4 studies was 1.58 (95% confidence interval [CI], 0.97-2.58). Removing the most recent study conducted in the United Kingdom reduced the heterogeneity (I(2) = 28.2%; P = .25) and provided a pooled OR (using a fixed effects model) of 1.38 (95% CI, 1.05-1.80). Swaddling risk varied according to position placed for sleep; the risk was highest for prone sleeping (OR, 12.99 [95% CI, 4.14-40.77]), followed by side sleeping (OR, 3.16 [95% CI, 2.08-4.81]) and supine sleeping (OR, 1.93 [95% CI, 1.27-2.93]). Limited evidence suggested swaddling risk increased with infant age and was associated with a twofold risk for infants aged >6 months.
  
  
  
  Heterogeneity among the few studies available, imprecise definitions of swaddling, and difficulties controlling for further known risks make interpretation difficult.
  
  
  
  Current advice to avoid front or side positions for sleep especially applies to infants who are swaddled. Consideration should be given to an age after which swaddling should be discouraged.
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom; a.pease@bristol.ac.uk.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Pease
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom;
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fleming
authors.affiliation: Departments of Family Medicine and.
authors.forename: Fern R
authors.initials: FR
authors.lastname: Hauck
authors.affiliation: Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia;
authors.forename: Rachel Y
authors.initials: RY
authors.lastname: Moon
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research and Department of Pediatrics, Monash University, Victoria, Australia;
authors.forename: Rosemary S C
authors.initials: RS
authors.lastname: Horne
authors.affiliation: TNO Innovation for Life, Child Health, Leiden, Netherlands; and.
authors.forename: Monique P
authors.initials: MP
authors.lastname: L'Hoir
authors.affiliation: Murdoch Childrens Research Institute, Royal Children's Hospital, University of Melbourne, and Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia.
authors.forename: Anne-Louise
authors.initials: AL
authors.lastname: Ponsonby
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom;
authors.forename: Peter S
authors.initials: PS
authors.lastname: Blair
mesh_terms: D001512:Bedding and Linens; D006801:Humans; D007223:Infant; D007224:Infant Care; D064887:Observational Studies as Topic; D016684:Prone Position; D013398:Sudden Infant Death / Q000209:etiology*