Pediatricians and researchers have long recommended crib sleep as the safest infant sleeping arrangement to prevent sudden infant death syndrome, or SIDS.
But University of Notre Dame anthropology professor James McKenna says he has uncovered evolutionary-based research that supports mother-baby co-sleeping as a safe and natural sleeping arrangement.
A diagnosis of exclusion, SIDS is characterized by the sudden unexpected death of a baby that is not predicted by medical history. By definition, the cause of SIDS is unknown, but there are several clear risk factors, including low birth weight, exposure to tobacco smoke, placing the baby in a prone sleeping position and not breast-feeding the baby.
World-renowned for his expert research on the infant sleeping practice of bed-sharing, a form of mother-child co-sleeping, in relation to breast-feeding, McKenna conducted the first physiological and behavioral studies of the differences between solitary and co-sleeping mother-infant pairs as director of the Mother-Baby Behavioral Sleep Lab at Notre Dame. He also published a book on the subject, titled "Sleeping With Your Baby: A Parent's Guide to Co-Sleeping."
"Co-sleeping is defined as mother and baby or father and baby or someone and baby having sensory access to that baby," McKenna said
"They're exchanging. They're responding. They're detecting sensory signals and cues."
McKenna distinguishes bed-sharing from separate surface co-sleeping, which simply means that the infant has sensory access but is not directly sharing a bed with the mother. Small infant beds that attach to the parents' bed, such as the Arm's Reach Co-Sleeper, promote separate surface co-sleeping and are quickly increasing in popularity.
Reducing the risk
The National Institute of Child Health and Human Development launched the Back to Sleep campaign in 1994 to encourage parents to have their babies sleep on their backs or in the supine position to reduce the risk of SIDS.
"In other cultures around the world, the position babies would be in is probably on their back nearby a mother," said Gail de Somer, leader of South Bend's breast-feeding support group La Leche League. "Back sleeping does seem to prevent SIDS. There's just no doubt about that."
Although SIDS rates have been steadily declining since the Back to Sleep initiative launched in 1994, more than 2,000 babies still die from SIDS each year in the United States, according to the National SIDS Research Center.
The American Academy of Pediatrics released a statement in October 2011 with recommendations for a safe infant sleeping environment, including room-sharing without bed-sharing, nonprone positioning of the infant, use of a firm sleep surface, breast-feeding and avoidance of overheating and exposure to tobacco smoke, alcohol and illicit drugs.
While the American Academy of Pediatrics recommends specifically against bed-sharing, McKenna claims that parents can practice bed-sharing safely in conjunction with breast-feeding because of the mother's ability to subconsciously communicate with the baby while sleeping. During bed-sharing, the mother and baby tend to spend more time in lighter stages of sleep, which creates a safer situation for the child.
"What we see in mother-baby bed-sharing studies is tremendous synchronicity of arousals and each kind of monitoring what the other is doing even if they don't consciously know it," said McKenna. "The physiology is so entwined. But with breast-feeding, the mom's breast-feeding like four, five, seven, nine times. That alone is a kind of re-engagement and a repositioning of the baby and an awareness."
Studies have shown breast-fed babies have a lower incidence of SIDS than bottle-fed babies. The American Academy of Pediatrics recommends exclusive breast-feeding for the first six months, followed by at least a year of supplemented breast-feeding.
"When a baby's breast-feeding, their tummy's down during the night, and so, that keeps the air passages open," de Somer said. "A breast-fed baby will wake more often to eat, which sounds like a disadvantage to a parent. But what that means is babies not getting in these really deep sleep states. They arouse more easily and therefore they don't have that episode where they're forgetting to breathe."
McKenna claims the argument for solitary sleeping is based more on social ideals than science.
"No studies showed babies did something more beneficial or had a life skill that they didn't get otherwise," McKenna said. "But the way people talk about it, you'd sure think that, boy, the evidence must be overwhelming that solitary sleep does something great for us as we grow up and feel confident in our gender identities, were happier or slept better."