Hmm... there's lots of conflicting views out there. Here's quite a good summary.
What Are the Benefits?
Swaddling can be a helpful tool in settling infants and enhancing health. Specifically, swaddled infants arouse less and sleep longer. Additional benefits have been found in preterm infants, including:
* Improved neuromuscular development
* Less physiologic distress
* Better motor organization
* More self-regulatory ability
* Pain relief
* Better temperature regulation
Benefits have also been seen in infants who cry excessively, who cried less when swaddled, and in infants with neonatal abstinence syndrome and neonatal brain lesions.
What Are the Risks?
Unfortunately, swaddling has some risks. When it is done improperly, swaddling can cause infants to become overheated, which can in turn increase the risk of SIDS. The risk of SIDS is also increased if a swaddled baby is placed in the prone position.
Another risk of swaddling is hip dysplasia, when the infants legs are incorrectly positioned. In addition, the tightness of the swaddling does seem to be related to a higher risk for respiratory infections. Swaddling may lead to delayed weight gain for some infants, perhaps by limiting tactile stimulation and thus the release of gastrointestinal hormones.
Parents who decide to swaddle should be aware of the risks. To mitigate the risk of hip dysplasia, parents can wrap the infants legs loosely. They can take care to monitor their infant so as to prevent overheating. They can keep the infant with the mother to hopefully address the delay in weight-loss recovery caused by swaddling. Finally (and perhaps most importantly), because of the increased risk of sudden infant death syndrome for a swaddled baby in the prone position, parents must stop swaddling their infants when they start attempting to turn.
That's from
http://www.babygooroo.com/index.php/200 ... swaddling/
It seems to sum everything up.
Elsewhere there's stuff about swaddling impairing motor function but as there are other studies showing that swaddled babies quickly catch up once they are no longer swaddled and this is a temporary thing I don't think it is something to worry about.
One very personal opinion I would like to make is that based on a list of benefits vs risks of crossing the road with a baby you might decide never to cross! I'm going to swaddle as long as it is effective and though I will take in to account the risks I think the above suggestions tell you how to avoid them.