When my own babies were small, neither social ideology nor wakeful babies caused me a lack of sleep. My babies slept snuggled up with me at night. My choice to co-sleep wasn’t based on research studies. This choice was simply ‘best practice’ for our family – or, where we all got the most sleep. Now there is a plethora of research about infant sleep and I find it fascinating to compare this to my own experience. Read – have my childrearing choices conveyed lasting benefits?

Recently, I searched for some long-term evidence of the benefits of parent-infant co-sleeping. I came across a study of college-age subjects which found that males who had co-slept with their parents between birth and five years not only had significantly higher self-esteem, they experienced less guilt and anxiety and reported greater frequency of sex.

Although I am uncertain how to objectively validate my own (or my kids’) experience in terms of this particular research, I can comfortably concur with the wealth of evidence that supports co-sleeping as an integral part of mother-infant bonding. (In this article, co-sleeping is defined as mother and baby sleeping within sensory proximity of each other including, but not necessarily, bed-sharing).

Science confirms what instinct has always sung in the hearts of mothers

They confirm that nature prepares mothers and babies to be able to commence their attachment as soon as the baby is born. Immediately after natural birth, certain hormones that are part of the birth process remain at high levels within the mother’s and baby’s bodies. The hormone plays a crucial role in the formation of their relationship. If this delicate balance of hormones is allowed to function in the very first moments after birth, by keeping mother and baby warm, in the skin to skin contact with each other, and free of distractions, mother and baby are exquisitely, chemically, primed to fall in love with each other

Fortunately, whatever the birthing experience, it seems that nature allows more than a single chance to cement the foundation for a loving relationship and reinforce the bonding process. Learning to love is an ongoing process for mother and baby and hormones continue to play an important role – day and night!

As women breastfeed, for instance, they receive doses of the love hormones oxytocin

The oxytocin stimulates the milk ejection reflex and prolactin, which has a calming effect on a mother as she breastfeeds. Endorphins, the hormones of pleasure and transcendence are also released during breastfeeding. It encourages the mother to repeat the breastfeeding experience. In turn, endorphins are transferred in the mother’s milk to her baby, giving the child a sense of contentment as he or she breastfeeds. Since prolactin levels are highest during night feeds, it makes sense to consider that proximity to her infant at night would elevate the loving feelings a mother would feel for her infant. Perhaps, without pressure to teach their babies to sleep all night as soon as possible. Mothers could appreciate night-time breastfeeds as an extra opportunity to bond with their babies.

Mothers and babies are hardwired to the experience of togetherness

For any mother snuggling a baby against her body, nuzzling her face into her infant’s baby-fine hair and smelling that sweet newborn breath, research to show that mothers and babies feel best when they are close to each other is about as necessary as research to show that grass will grow if it rains. However, there is indeed scientific evidence that mothers and babies are hardwired to the experience of togetherness.

One argument in favour of continuous mother-baby togetherness is that infants get to know and bond with their mother through all of their senses – eye contact, the sounds of the mother’s voice, her touch and her smell.

Attachment, the process of ‘learning to love’, is a behavioural system that operates 24 hours a day. It does not deactivate during sleep when infants spend up to 60 per cent of their time. As obstetrician Michel Odent observes “It takes only the most elementary observation to see that a baby needs its mother even more during the night than in the daylight. In the dark, the baby’s predominant sense – sight – is at rest. Instead, the baby needs to use its sense of touch through skin-to-skin contact, and its sense of smell.”

Co-sleeping with your baby

According to Professor James McKenna, director of the mother-baby sleep laboratory at the University of Notre Dame, Indiana, “co-sleeping is a safe and even potentially life-saving option, as long as parents provide a safe sleeping environment (see box).” Professor McKenna has extensively studied both mothers and babies both co-sleeping and sleeping separately. His research demonstrates what co-sleeping mothers will attest to when mothers and babies sleep together, they tend to get into the same sleep cycle. The mothers, even in deep sleep were aware of their babies’ positions and would move to avoid lying on them or impeding their breathing. Although the co-sleeping babies spent less time in deep sleep and were aroused more frequently (though not necessarily waking), their mothers actually got MORE sleep than the mother-baby pairs sleeping in separate rooms.

As a researcher in SIDS (Sudden Infant Death Syndrome), Professor McKenna explains that these small transient arousals may lessen a baby’s susceptibility to some forms of SIDS which are thought to be caused by failure to arouse from deep sleep to re-establish breathing patterns. The babies in his studies who sleep with their mothers also tend to sleep on their backs or sides and less often on their tummies, another factor that could reduce the risk of SIDS. Professor McKenna advises “from an evolutionary and biological perspective, proximity to parental sounds, smells, gases, heat and movement during the night is precisely what the human infant ‘expects’, and in our push for infant independence, we are forgetting that an infant’s biology cannot change quite as quickly as cultural child-care patterns.”

For mothers who enjoy sharing sweet dreams with their baby

The research is affirming – touch and proximity are essential elements of bonding; the hormonal status that enhances bonding is at its most effective during night-time breastfeeding. Continued breastfeeding maintains the release of hormones essential for mother-infant bonding. Moreover, breastfeeding is more likely to be successful for a longer duration when mothers and infants share sleep.

If, despite the evidence, you are facing criticism (“you will never get him out of your bed!”), take heart, my children are no longer sleeping with me. However, now that they are college age, according to the research, it seems they could well be sleeping with somebody else!

Safe co-sleeping

• Do not sleep with your baby if you are under the influence of any substance. Examples of this are alcohol or medication (even if prescribed). This could induce a deeper sleep and reduce awareness of your baby (either partner).
• Do not co-sleep if you are a smoker (either partner).
• Sleep on a firm, flat surface (not a waterbed, couch or sofa).
• Keep baby’s head uncovered and do not use doonas, to avoid overheating.
• If you have long hair, tie it back, and consider that very large breasts or extreme obesity may reduce awareness of your baby’s position.

Co-sleeping Links

Professor James McKenna
www.nd.edu/~jmckenn1/lab
Professor McKenna is the director of the Mother-Baby Behavioural Sleep Lab at the University of Notre Dame, Indiana. Professor McKenna is an acclaimed expert in the areas of infant sleep, breastfeeding and Sudden Infant Death Syndrome (SIDS).

Ask Dr Sears
www.askdrsears.com
Site of Attachment Parenting “guru”, paediatrician William Sears and his sons – also paediatricians. A very informative site offering evidence-based information about all aspects of parenting, including co-sleeping.

Revised on 30th November 2021