This was a very interesting article entitled Why babies should never sleep alone: A review of the co-sleeping controversy in relation to SIDS, bedsharing and breast feeding. It’s too long to really do justice to in a short post, so I will recommend that you read the full thing, although I will give some thoughts on it. Dr. McKenna is very biased towards babies sleeping with their mothers, and this article will give you a good idea of why, along with the (flawed) reasoning that has kept co-sleeping from being promoted as being good for both mothers and babies.
Some of the issues he brings out about research into this topic is that many of the scientists who looked at infant sleeping were biased towards the idea that it was a good and laudable goal for babies to sleep by themselves in a crib, and that the earlier they slept through the night, the better. Back in the ’50s and ’60s, the study of infant sleep was (pun intended) in its infancy; and the subjects of the studies were basically formula-fed crib-sleeping infants. Since breastfeeding was actively discouraged (idiot doctors actually thought formula was superior to breastmilk), the “norm” was bottle-feeding, although bottle-feeding is obviously not “normal.” The sleep patterns of these babies was set up as “normal” and also as the goal for subsequent generations
So, the first flaw was the crossing over of cultural ideals — bias about what should be — into the scientific studies and literature of the time, which basically influenced all studies ever since. Most people have pretty solid ideas about how babies should sleep (whether alone or with someone, through the night as quickly as possible, etc.), which are bound to influence their interpretations of the benefits of co-sleeping. Reading some of the studies he mentioned and results he had in his own sleep lab, I gotta admit that seeing that infants who sleep alone sleep for longer stretches of time than infants who sleep with their mothers made me say that crib-sleeping is a great benefit for mothers who need or want more sleep. However, he points out that mother-baby pairs who co-sleep get more total sleep than those who don’t. This makes very good sense, because when you breastfeed and co-sleep, when the baby wakes up to nurse, all you have to do is offer the breast when he starts rustling around; but when the baby is in another room, he first has to wake up enough to cry, scream loudly enough to wake you up, then you have to get your weary body out of bed, shuffle down the hall, get the baby out of the crib, sit in the rocking chair and nurse him back to sleep, and finally shuffle back down the hall to your bed and try to fall asleep again.
Let me just put in my own experiences here, because personal experiences always color one’s views of a matter.
Having been influenced by the typical home-birthing mindset, one of the things I planned on doing was to have my baby sleep with me for probably the first several months. I didn’t look far enough into the future to see if we would have a “family bed” or not — my philosophy is to take things as they come, and I wasn’t sure if I and my husband would both like it or not. For the first few weeks, I had Keith in our king-size bed with me. I was afraid of rolling over on him, so I had him between me and my husband — close by, but not touching. But my husband was so afraid that he’d roll over on him, or put his pillow on him, that he slept very poorly, and I soon moved to the middle of the bed and had my son on the edge of the bed (we had a bed rail, of course). After a few weeks, I realized that I was waking up a lot even when Keith wasn’t, and I felt like I was robbing myself of precious sleep time (because I would arouse and then wake up, get ready to nurse, realize that Keith was not actually awake, and then try to go back to sleep before he did actually wake up 30-60 minutes later). So, I gradually moved him to the crib (in our room) from about 4-6 weeks of age onward.
Because of the living situation when my second son was born, we had a bassinet beside the bed instead of the crib for several months. I used it a lot, but he also successfully slept with me. Maybe it was because I was more comfortable with more experience, or just more tired because of having a toddler and a newborn, but I frequently had Seth asleep in the crook of my arm, and I was able to sleep even though he was touching me. Perhaps we slept better with skin-to-skin contact, and if I had stumbled on that sleep posture with Keith, we would have co-slept longer. We frequently slept in the same bed, with him in the crook of my arm (at least partially as a protective measure against my husband rolling over on him on one side, and him rolling off the bed on the other side — though we had a king-size bed so plenty of room) for several months, moving him out of the bassinet only when he began to sit up, and gradually moving him into the crib around 6-9 months of age.
So, I’m an advocate for co-sleeping, but I know sometimes it doesn’t work out the way you plan. Back to the article.
Other problems Dr. McKenna noted in the various studies that look at this question, is that there are many different possible factors when babies share a sleeping surface with the parents, and often these differences are not noted in studies (or reports of SIDS deaths, or whatever). For instance, there is a big difference between women like me who chose to co-sleep and breastfeed for the infant benefits, and women who bottle-feed and sleep with their babies because they can’t afford separate sleeping arrangements. Other factors include the type of bed (waterbed, couch, etc.), whether the adults in the bed are all drug-free (including alcohol and certain OTC meds that may cause drowsiness), whether the parents smoke, if the baby sleeps on his back or tummy, or is put on a pillow, etc. (Here is a link to Dr. Sears’ “Sleep Safety” webpage, which has a good basic rundown of do’s and don’ts for both crib and co-sleeping.) So, there are factors that make bed-sharing hazardous. The problem is when studies don’t account for these risk factors, and just say, “Oh, well, the baby was sleeping in the same bed as the parents when it died of SIDS, so bed-sharing is dangerous!” Dr. McKenna points out,
Surely, the fact that in Japan safe bedsharing and futon co-sleeping is increasing as SIDS rates decline to unprecedented levels should raise some doubts about any singular or predictable positive association between bedsharing and SIDS rates. Moreover, data on recent Asian immigrants in the USA lead to an interesting observation: the longer different Asian immigrant sub-groups live in the USA and presumably begin to adopt American life styles, including placing their infants in cribs for night-time sleep rather than co-sleeping, the more the SIDS rates of these ethnic groups begin to rise to match the higher rates of SIDS among whites.
There were numerous other benefits to co-sleeping, including the fact that when babies sleep with someone (typically the mother, but not always), their breathing, heart rhythm, and temperature are all better regulated.
Currently, however, it is considered poor parenting, and possibly even dangerous, to let your baby sleep with you. Dr. McKenna is not suggesting that all forms of bed-sharing are risk-free; however, he is lobbying hard for its condemnation to be removed, and more scrutiny given to deaths that occur when infants sleep with their parents. One study he quotes says,
Almost all SIDS deaths associated with parental bedsharing occurred in conjunction with a history of parental drug use and occurred in association with the prone [on the tummy instead of on the back] sleep position or sleep surfaces such as a couch or waterbed.