There is an article in the Guardian today about how a study by US researchers suggests that most cases of SIDS can be explained as accidental suffocation. Often times they are cases where the babies were sleeping with their parents and suffocated on their arms or pillows, or where something soft was in the bed. Sometimes their breathing was already compromised because they were sick.
I didn't find other mentions of this study in other newspapers, so I googled its authors and came about a very frightening presentation that included one of them. The researchers interviewed the parents of babies who were diagnosed with SIDS to find out exactly how they were sleeping, in many cases it was clear that their airducts had been or at least could have been obstructed.
As an avid cosleeper this is quite frightening information. I feel like I dodged a bullet and I wonder if I'm putting my now 13 months old baby at risk by keeping her in bed with us.