Carmel Therese Harrington, Naz AlHafid, and Karen AnnWaters write,
BChEsa, measured in dried blood spots taken 2-3 days after birth, was lower in babies who subsequently died of SIDS compared to surviving controls and other Non-SIDS deaths. We conclude that a previously unidentified cholinergic deficit, identifiable by abnormal -BChEsa, is present at birth in SIDS babies and represents a measurable, specific vulnerability prior to their death.
As opposed to the superstitions that support back-sleeping.
But Emily Oster says,
all of the safe-sleep guidelines — and especially the guideline about putting your child to sleep on their back — are completely unchanged and extremely important.
I would say that we at least have an avenue for research. Are the children with this abnormality less likely to die if they sleep on their backs? Perhaps there are strong theoretical reasons to believe that this is the case, in which case the new finding reinforces the case for back-sleeping. And perhaps one could study it empirically, by carefully monitoring two groups of infants with this abnormality to ensure that they are quickly revived if they start to experience distress, but letting one group sleep on their back and one sleep on their stomach. Then see which group experiences more incidents of distress. But if back-sleeping cannot be shown either theoretically or empirically to decrease the chances of death for infants with this abnormality, then I think that is a strike against back-sleeping.
I think everyone is understandably squeamish about experiments involving babies, even if they are carefully monitored to keep at-risk infants safer than they might be at home.
Any decent research about how babies sleep in traditional or foraging societies?