Minimizing the risks of sudden infant death syndrome: to swaddle or not to swaddle?

To evaluate the effects of swaddling on infant arousability, particularly the progression of subcortical activation (SCA) to full cortical arousal (CA), because impaired arousal may contribute to sudden infant death syndrome.

Healthy term infants, who were routinely swaddled (n = 15) or unswaddled (n = 12) at home, were studied with daytime polysomnography at 3 to 4 weeks and 3 months after birth. When both swaddled and unswaddled, arousability was assessed with a pulsatile jet of air at the nostrils.

Larger increases in overall arousal thresholds (SCA plus CA) with swaddling were observed in infants who were easiest to arouse when unswaddled. Swaddling did not alter SCA or CA frequencies of routinely swaddled infants at either age. In infants who were naïve to swaddling, arousal thresholds were increased and CA frequency decreased during swaddled quiet sleep at 3 months.

This study provides a scientific basis for assessing the safety of swaddling in infant care practice. The decreased cortical arousals observed in infants unfamiliar with swaddling may correspond to the increased risk of sudden infant death syndrome for inexperienced prone sleepers.