​The risk of Sudden Infant Death Syndrome (SIDS) appears to increase when infants are swaddled while sleeping prone or on their sides, according to a research analysis in the June 2016 issue of Pediatrics. 

Four studies were deemed eligible for inclusion in the review because of their relevance. The studies spanned two decades and covered three diverse areas, including regions of England; Tasmania in Australia; and Chicago, Ill. None of the studies gave a precise definition for swaddling, which is a traditional practice of wrapping infants to promote calming and sleep.

Despite the studies’ limitations, the analysis indicates that current advice to avoid placing infants on their stomach or side to sleep may especially apply to infants who are swaddled. The risk associated with being placed in the side position almost doubled among swaddled infants, according to the review. The risk of SIDS doubled in infants who were swaddled and found on their stomachs. The risks also were higher for older infants who were swaddled during sleep.

The studies suggest that the majority of those found on their stomachs moved into this position after being placed on their sides or backs. The association between swaddling and SIDS remains unclear.