Hi Pam
A number of studies have found that babies of smokers (particularly those smoke exposed in utero) have depressed arousal mechanisms during sleep. As bedsharing is a sleep environment where babies may be occasionally exposed to mild physiological stressors, babies who are lacking normal arousal responses will experience a higher of degree of risk (and babies of smokers are more vulnerable to SIDS, but even more vulnerable if they bedshare). Non-smoke exposed babies arouse, shift position, move covers, alert parents etc if their breathing is compromised. A baby with a depressed arousal response may be less able to do this. Check out the research of Rosemary Horne (Australia) and Patricia Franco (Belgium) on this topic (some links below). 

http://www.ncbi.nlm.nih.gov/pubmed/10393601
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1721454/

Regards
Helen

Professor Helen Ball
Head of Anthropology, Durham University, Dawson Building, South Road, Durham DH1 3LE, UK
T:0191 334 1602 F:0191 334 1615 E:[log in to unmask]
www.dur.ac.uk/anthropology; www.dur.ac.uk/sleep.lab
__________________________
Infant Sleep Information Source
www.isisonline.org.uk
__________________________

             ***********************************************

Archives: http://community.lsoft.com/archives/LACTNET.html
To reach list owners: [log in to unmask]
Mail all list management commands to: [log in to unmask]
COMMANDS:
1. To temporarily stop your subscription write in the body of an email: set lactnet nomail
2. To start it again: set lactnet mail
3. To unsubscribe: unsubscribe lactnet
4. To get a comprehensive list of rules and directions: get lactnet welcome