Infant swaddling, an old practice that has recently gained popularity in the United States, may be linked to increased risk of
sudden infant death syndrome (SIDS). A new review of 760 SIDS cases in the journal Pediatrics found that infants who were swaddled - wrapped in light cloth with only the head exposed - were about a third more likely to die from SIDS. The risk was higher among infants sleeping on their stomachs or sides, positions already known to be more dangerous for sleeping babies. SIDS risk among swaddled infants was also higher for children older than 6 months, suggesting that swaddling should be stopped when babies are able to start rolling over. The researchers cautioned that these results should be taken with a grain of salt, as there is still relatively little data on the connection between SIDS and swaddling.
Source: http://www.sciencemag.org/news/sifter/infant-swaddling-increases-sids-risk