Question: Pediatrics has its share of issues that always give rise to strong emotional responses. No matter what position you take on, for instance, breast-feeding, pacifiers, or vaccines, someone is bound to come after you with a pitchfork. Exactly where the baby sleeps is another such topic. For years, most pediatricians have gently (or vigorously) urged parents to let their infants sleep in a crib, a bassinet, or, indeed, almost anywhere but the parents' bed. Parents—especially in the last few years—have pushed back against doctors, arguing that it is both natural and beneficial for babies to co-sleep with parents. The people who favor bed sharing believe that it promotes successful breast-feeding, strengthens mother-child bonding, and may even allow parents to detect and halt Sudden Infant Death Syndrome. But is there any evidence to support these claims—and the overall safety of co-sleeping?
Answer: Here come the pitchforks. Not only are there no good data to support these beliefs, but a new study supports what most pediatricians have been saying all along: There is substantial risk in infant-parent bed sharing, and parents should be aware of this risk before bringing babies to bed to sleep with them.
Methodology: The study tracked mortality patterns in the United States over a 20-year period ending in 2004. The researchers collected death-certificate information about all babies who died suddenly and whose deaths were unexpected. For many of the children whose deaths fell into this category, no definite cause could be assigned; these are the children who traditionally have been thought to be victims of SIDS. That number has been dropping dramatically during the 20-year period under study, almost certainly a result of the "back to sleep" campaign, which followed the discovery that the risk of SIDS goes up when babies sleep face-down. But there is another category of unexpected infant deaths, one in which death-scene analysis permits a plausible cause of death to be assigned: accidental suffocation and strangulation in bed. Those numbers have quadrupled in the two decades under study.
Some of those cases obviously have nothing to do with bed sharing—like strangulation in a defective crib. (Among deaths for which the sleeping surface was known, about 15 percent occurred in cribs.) But in cases of sudden, unexpected infant deaths attributed to suffocation or strangulation, more than half occurred in co-sleeping circumstances (and where the sleeping surface was noted, more than 80 percent of the deaths occurred in an adult bed, a sofa, or a couch). A variety of causes were implicated in these deaths, including suffocation by bedding or soft materials and wedging between two objects, but the single most common cause was "overlying," in which a deeply sleeping parent rolled over and suffocated a baby.
Conclusion: This study doesn't really give us the answer about the safety or risk of co-sleeping—it just raises enough questions to make us very nervous. There are some ways that have been suggested to minimize the risk to the baby for those who want to continue co-sleeping, though there are no good studies to back them up. Putting the baby in a little outrigger attached to the side of the parents' bed or in a small canoelike device in the bed itself have been suggested as methods that might decrease the risk. (The sleeping chamber should have a firm bottom and not be filled with loose bedding or stuffed creatures.) Also, don't even think of bed sharing if you have been taking any medication, including antihistamines, which might make you sleep more deeply, or if you have been drinking an alcoholic beverage. But until we have a better study, I think it is important for parents to know that bed sharing, which might have some benefits, could well also have some very significant risks.