Correct swaddling probably decreases SIDS risk

Supine swaddling decreases SIDS risks

van Sleuwen, et al1 are to be commended for their comprehensive review of swaddling. Particularly noteworthy is their mention of the potential value of supine swaddling in protecting babies from SIDS. The authors state, “Epidemiologic evidence clearly shows that being supine and swaddled decreases the SIDS risk more than being supine and unswaddled.” Yet, inexplicably, this important finding was omitted from the paper’s abstract, discussion and conclusion.

The authors cite three studies reporting lower SIDS incidence with supine swaddling 2 3 4 (two were large studies with adjusted odds ratio for SIDS risk of 0.64 and 0.69 in swaddled non-prone versus unswaddled non-prone babies).

In this systematic review, four possible mechanisms of swaddling’s protective effect are mentioned: 1) Physical inhibition of rolling to prone (routine prone sleeping doubles or triples SIDS rates, but for babies who routinely sleep nonprone and accidentally roll prone the SIDS rate rises 8-33 times 5 6 7); 2) Prevention of excessive cooling (the authors note that cooling stress is even more highly correlated with SIDS than over-heating 4 8 9 10); 3) Physical inhibition from accidentally moving into bulky bedding 4; 4) Increasing supine positioning. (Fifty percent of parents who place their babies to sleep prone do so because they sleep better in that position 1. Snug wrapping promotes parental compliance with “back to sleep” recommendation because it reduces sleep arousals thereby fostering better sleep 11 12 13).

An additional protective effect of swaddling, not included in the author’s’ discussion of SIDS, is an increase in a sleeping baby’s arouseability. 12 13 This important point is somewhat unclear in the article. The authors don’t adequately distinguish between arousals and arouseability. They state, “Theoretically, the decreased arousal associated with swaddling could also prevent arousal in life threatening situations.”

However, it must be noted that although swaddled babies have fewer arousals, swaddling actually increases arouseability. In other words, wrapped babies sleep longer, but rather than being in a “deep” sleep, from which they cannot easily be aroused, they are in a “lighter” sleep, from which they are more easily aroused (e.g. by noise). Increased arouseablity is believed to be protective from SIDS.

Over the past decade, the “Back to Sleep” campaign has made enormous progress in decreasing SIDS deaths. However, SIDS has not been fully eradicated and, as mentioned in the AAP Task Force report on SIDS 14, new prevention strategies are needed. Supine swaddling appears to offer significant promise in that regard and warrants further investigation.

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