An Overview of the Benefits of Co-sleeping

For the vast majority of mothers and babies around the world, co-sleeping is the cultural norm and the natural thing to do. In the U.S., according to the Center for Disease Control, co-sleeping is also quite a common occurrence with roughly 68% of all babies enjoying co-sleeping at least some of the time. However, in some countries, predominantly in the U.S. and some Northern European countries, co-sleeping has become a controversial practice with strong proponents and equally strong opponents. Sensationalist media has exacerbated this controversy, so a cool look at the facts may be helpful.

Let us begin with examining the concept of co-sleeping – what exactly is meant by this term? Co-sleeping refers to the many different ways a baby sleeps in close emotional and physical contact with their parents, usually within arm’s reach. Co-sleeping thus implies that the baby and parent can be bed-sharing, i.e., sleep in the same bed on the same surface. The baby can also be placed on a separate surface, as in a bassinet, which is attached to the parents’ bed and also has an open side towards the parents’ bed for easy contact. A third approach is to have the baby sleep in the same room, but in a separate crib or bassinet.

Incidentally, in part because of the controversy surrounding co-sleeping, the practice has been investigated thoroughly by researchers over the past three decades, and we now have a good overview of the benefits and risks associated with co-sleeping. Conversely, we also know the risks associated with NOT co-sleeping.

Babies’ benefits of co-sleeping

Babies’ benefits of co-sleeping listed by the researchers include the following:

The baby receives continual reminders of caregivers’ presence – touches, smell, movement, warmth and taste (from nightly breast feedings) and is thus reassured.

In case of a threat to the baby’s wellbeing (if the baby is e.g., choking), a light sleeping mother will be able to help right away.

Babies co-sleeping tend to cry less or not at all, resulting in lower levels of stress hormones.

Babies are warmer when sleeping next to their mothers – lower temperatures can reduce immunity, making baby more susceptible to infectious diseases and divert energy away from growth and development.

If the baby is breastfed and co-sleeping, the researchers have found the following benefits in addition to the above:

Babies who sleep with their mothers and breastfeed spend less time in the deepest  stages of sleep. Light stage sleep is thought to be physiologically more appropriate and safer for babies, because it is easier to awaken to terminate apneas (episodes where one stops breathing), than it is when babies are in deeper stages of sleep. The mother’s movements and the smells of mother’s breast milk nearby both contribute to the baby remaining in lighter sleep for longer periods of time.

The babies stimulate their mothers’ milk supply by breastfeeding during the night. The breast feedings are also more frequent and longer, which means greater weight gain.

Babies and mothers have a heightened and enhanced sensitivity to each other’s smells, movements and touches.

Parents’ benefits

There are benefits for the parents, too.

It is not unusual that parents will initiate co-sleeping when their baby is found to have sleep disturbances, prompting the parents to have to get up and out of bed several times per night. In the end, they often realize that they will get better and more sleep, if they simply co-sleep with their baby. With the baby so close, the mother can breastfeed while half-asleep, rather than having to wake up and go to another room to tend to a crying baby

Co-sleeping is often found to enhance the whole breastfeeding experience for the mother, with mothers maintaining breastfeeding for a longer duration, compared to non   co-sleeping parents.

Working parents also report how greatly they appreciate the contact with the baby that co-sleeping allows, which makes up for the lack of contact during day hours. “Peaceful,” “comforting,” “loving” and “protective” are words that show up repeatedly when parents state their reasons for co-sleeping. Some researchers point to the effects  of oxytocin and the skin-to-skin contact that many parents will have with their baby when co-sleeping, resulting in lower stress levels in the parents and baby alike.

Risks associated with co-sleeping

Turning to the risks of co-sleeping, much of the controversy surrounding co-sleeping is really about the risks associated with bed-sharing. Here the parent(s) and the baby share the same bed. Interestingly, even the conservative and risk-averse American Academy of Pediatrics (AAP) in their Sudden Infant Death Syndrome (SIDS) policy statement of 2005 does in fact recommend co-sleeping in the shape of a separate but proximate sleeping environment. The Academy recommends co-sleeping as the risk of SIDS has been shown to be reduced when the infant sleeps in the same room as the mother.

Advocates of the baby sleeping in a separate room should thus be aware that AAP has found that this practice has a higher risk of SIDS associated with it, relative to a co-sleeping arrangement.

AAP in their policy statement also refers to “co-sleepers” (infant beds that attach to the   mother’s bed) and how they provide easy access for the mother to the infant, especially for breastfeeding. AAP however indicates that safety standards for these devices have not yet been established by the Consumer Product Safety Commission.

Risks associated with bed-sharing

As regards the position of AAP on bed sharing, their view is that “bed-sharing, as practiced in the United States and in other Western countries, is more hazardous than the infant sleeping on a separate sleep surface” and therefore recommends against it.

Researchers who have scrutinized bed-sharing over the past several decades in dedicated sleep-laboratories find this recommendation to be too general and imbalanced. There certainly are risk factors that should be taken into consideration when bed-sharing, but if heeded, the researchers find that bed-sharing is a safe and recommendable practice.

The risk factors for bed-sharing include the following: Obese parents; parents who smoke (either during pregnancy or at present); parents sleeping on a waterbed, recliner, sofa, armchair, couch or bean bag; parents who sleep on multiple pillows, a sagging mattress or a sheepskin or use heavy bedding, such as comforters or duvets; sleeping in overheated rooms; parents under the influence of drugs or alcohol; other children or pets who can or are likely to climb into the bed; and stuffed animals on the bed that could cover the baby’s face.

Also, if routinely bed-sharing, it is ideal to pull your bed away from the walls and surrounding furniture into the center of the room, strip away metal or wood framework and lay the box spring on the floor with the mattress on top.

Data from Consumer Product Safety Commission indicate that the greatest risks to a baby sleeping in a bed with an adult is not, as many would assume, from an adult overlaying or rolling over onto the baby, but from the infant strangling or becoming wedged or trapped between a wall, a piece of furniture, the bed frame, headboard or footboard and the mattress.

Will co-sleeping affect my child’s development?

Some pediatrics have voiced concerns that co-sleeping will hinder the development of the child’s independence. One study has found that, compared with solitary sleepers from birth, infants who co-sleep from birth, either learn or accept sleeping alone about a year later than infants who have no choice but to sleep alone. On the other hand, you as a parent will not have had the great feelings and memories from co-sleeping with your baby, if you let your baby sleep in a separate room.

Parents wanting to end their co-sleeping with their baby ought to be much helped by the gradual approach described by Elizabeth Pantley in her book “The No-cry Sleep Solution.”

Overall, there certainly is no reason for concern for your child’s capability of independence. Various studies indicate that co-sleeping infants develop more permanent capacity for self-sufficiency, resilience, comfort with affection and the ability to be alone when necessary.


Most babies do not mind sleeping alone during daytime naps. However, contrary to advice, the idea of “sshhhhh – the baby is sleeping” only conditions the baby to sleep lightly and to stir at each extraneous noise. So feel free to place the baby’s  bassinet in a room where there are active and vocal people (including children) around.

The impact of co-sleeping on parents’ relationship

One of the questions often raised in relation to co-sleeping is how will it affect the parents’ relationship. The short answer to that is that all families are unique, so it is hard to say with any degree of certainty how it will affect your relationship. Fathers often find co-sleeping to be emotionally rewarding, especially if they are separated from the baby during daytime which is the case for most fathers. And co-sleeping does not have to affect tenderness and closeness between spouses – talk, touch, massage and laughing with a sleeping baby present are certainly feasible.

Maintaining intimacy will require a little more creativity, but again here parents find their own ways that are compatible to their circumstances and values.

In the end, sleeping arrangements are a very personal choice, with many aspects to consider, but at the very least, parents should not be made to feel guilty for choosing to co-sleep, as indeed this practice does confer a range of benefits on both parents and baby, if carried out conscientiously and responsibly.

Happy sleeping!


James J. McKenna. Sleeping with your Baby. Platypus Media 2nd edition 2009.

Maria Goodavage and Jay Gordon. Good nights: the Happy Parents’ Guide to the Family Bed. ISBN: 312275188

Elizabeth Pantley. “The No-cry Sleep Solution”. McGraw-Hill 2002.

William Sears. Nighttime Parenting: How to Get Your Baby and Child to Sleep. ISBN: 452281482

Helen Ball, Sally Inch and Marion Copeland. The Benefits of Bedsharing. DVD. Platypus Media. 2005.


Dr. Henrik Norholt is a member of The World Association of Infant Mental Health. He holds a Ph.D. from the LIFE faculty of Copenhagen University and is a resident of Copenhagen, Denmark. He has been studying the effects of baby carrying as it relates to child psychological and motor development through naturalistic studies since 2001.

He is actively engaged in the study of current and past research into baby carrying through his large international network of family practitioners, midwives, obstetricians, pediatricians and child psychologists and shared his insights with the subscribers to Ergobaby’s blog.