A BBC article Bed sharing 'risks babies lives warns against co-sleeping with your baby. Here's a quote from the article:
"We need to make all parents aware that the most comfortable place for them to sleep is the most dangerous place for their baby."
I think the true purpose of this article is to scare the reader.
The article does not back up this claim. The article does not provide evidence that sudden infant death occurs more often when co-sleeping than when not co-sleeping. The evidence simply shows that smoking, drinking, and premature birth are all risk factors for SIDS, regardless of whether co-sleeping is practiced. To conclude from this evidence that co-sleeping is a risk factor would be like concluding that driving is dangerous simply because drunk driving is dangerous. No, driving is dangerous because you are more likely to die while driving than while not.
The article cites a statistic that out of 50 cases of infant death, "31 were found to have been sharing a bed or sofa with a parent". So, 62% of deaths occurred while the parents were sharing a bed or sofa with their baby. This statistic is useless unless compared to the percentage of parents that regularly share a bed with their baby. If 80% of couples co-sleep with their baby, but only 62% of sudden infant deaths occurred while co-sleeping, then what would you conclude?
There is in fact evidence that co-sleeping decreases the risk of SIDS. Erinne found this article, which dives into the statistics in much greater detail and shows that co-sleeping is less than half as risky as sleeping in a crib.