Co-sleeping: traditions, safety and what the evidence says

Newborn · Sleep · Reviewed 20 June 2026 · All articles

Few topics in new-parent life create more quiet tension than where a baby should sleep. Official guidelines say one thing. Your mother, your mother-in-law, or the culture you grew up in may say another. Friends on both sides of the debate hold their positions with conviction. And you, at 3 am with a baby who will only settle on your chest, are just trying to survive the night.

This article is not here to shame you into one choice or another. It is here to give you the clearest possible picture of what the evidence actually shows, what the risks are and when they are highest, what the safest compromises look like, and how to have calm conversations with family members who see things differently. The goal is that you feel informed, not judged.

The family bed tradition

Across much of the world, sharing a sleep space with a newborn is not a fringe parenting choice. It is simply what families do. In Japan, the practice of kawa no ji (sleeping in the shape of the river, with parents on either side of the baby) is widespread. In India, a mother and baby sharing a sleeping mat is entirely ordinary. In Latin America, the family bed is unremarkable. In many parts of the Middle East and Africa, a baby sleeping apart from its mother would raise far more concern than one sleeping beside her.

In Italy and across the broader Mediterranean region, the tradition is similarly rooted. Il lettone, literally "the big bed," is a phrase most Italian parents recognise immediately. It refers to the family bed, a place where children, especially young babies, have historically been welcomed as a matter of course. Nonne (grandmothers) who raised several children in the 1960s, 1970s and 1980s are often puzzled by the idea that a baby should sleep alone in a separate room. To them, keeping a baby close through the night is simply love made practical: it makes breastfeeding easier, it settles the baby faster, and it means everyone gets more rest.

It is worth holding this context firmly in mind when reading official guidelines. The guidelines were written largely in high-income, Western, heavily medicalised healthcare contexts, and they are responding in part to specific patterns of infant death associated with particular risk factors. They are not a verdict on the parenting of billions of people across generations and cultures. They are an attempt to identify which specific conditions make bedsharing more dangerous, and to reduce deaths in those contexts. Those are two very different things.

What the evidence shows

The most thorough recent synthesis of bedsharing evidence comes from UNICEF UK, whose Baby Friendly Initiative published a detailed evidence review in 2023. Their conclusion was nuanced: bedsharing is not uniformly dangerous, and the risk is highly context-dependent. The key variables are the conditions under which bedsharing happens, not the practice in the abstract.

Professor James McKenna, director of the Mother-Baby Behavioral Sleep Laboratory at the University of Notre Dame, has spent decades studying the biology of mother-infant sleep. His research documents that breastfeeding mothers and their babies exhibit synchronised arousals during the night: when sharing a sleep surface, they tend to wake and rouse together, which may reduce the depth of sleep in the baby during vulnerable periods. His work also found that bedsharing is associated with longer breastfeeding duration, which itself has significant health benefits for both mother and baby.

McKenna coined the term "breastsleeping" to describe the specific combination of bedsharing and breastfeeding, arguing that the two practices are biologically intertwined and that the evidence against bedsharing was generated largely in populations where formula feeding was common, making it difficult to separate the risks accurately. This is a legitimate scientific argument, and it has gained traction in the research literature, though it has not yet changed the headline recommendations from major paediatric bodies.

What is clear from the evidence is this: the vast majority of bedsharing-associated infant deaths involve one or more significant risk factors (soft surfaces, alcohol use, smoking, prematurity). When those risk factors are absent, the absolute risk is substantially lower. It is not zero, but it is much smaller than the headline figures often suggest.

The risks: when bedsharing is most dangerous

The American Academy of Pediatrics (AAP) published updated safe sleep guidelines in 2022. These remain the most comprehensive and widely cited. The AAP recommends against bedsharing in all circumstances, but their own risk stratification makes clear that certain situations carry dramatically higher risk than others. Understanding those situations is essential.

Soft, unsafe sleep surfaces. Sofas and armchairs are by far the most dangerous place for a baby to sleep, with or without an adult present. The risk of suffocation on a soft, uneven surface with gaps and cushions is extremely high. If you fall asleep while feeding on the sofa, move yourself and your baby to a flat surface as quickly as possible. This is the single clearest harm-reduction message in the entire debate.

Alcohol and sedating substances. If either parent has consumed alcohol, cannabis, or any sedating medication (including some antihistamines and prescribed sleep aids), bedsharing should not happen. These substances reduce an adult's ability to rouse and respond to a baby's position or distress during sleep. This risk factor is strongly and consistently supported by the evidence.

Smoking in the household. Even if no one smokes in the bedroom or near the baby, a baby living in a household where any member smokes faces a significantly higher risk of SIDS. This risk is compounded when bedsharing occurs. The AAP guidance here is unambiguous.

Premature or low-birthweight babies. Babies born before 37 weeks gestation or weighing less than 2.5 kg at birth are at higher risk during sleep in all settings. The safe-sleep guidelines apply more strictly for these babies, and bedsharing is strongly discouraged until the baby has reached and maintained a healthy weight and corrected gestational age.

Soft bedding, pillows and duvets near the baby. Even on an otherwise firm mattress, pillows and heavy duvets create suffocation and overheating risks. If a baby is sharing a sleeping surface with adults, adult bedding should be kept away from the baby entirely.

Overcrowding and sibling or pet presence. Other young children or pets sharing the bed with a baby increase the risk of accidental overlay or smothering.

Being clear about these risk factors is not alarmism. It is the information that allows you to make genuinely informed decisions rather than blanket ones.

Safer ways to keep baby close

The tension between cultural norms and official guidelines is often false, because there is significant middle ground between "baby in a separate room, alone in a cot" and "baby in the family bed on a soft mattress under a duvet." That middle ground is where most harm-reduction advice now sits.

Room-sharing with a separate surface. The AAP and NHS both recommend this as the default. A firm-sided cot, crib, or Moses basket placed in the parents' bedroom, close to the bed, means the baby is within arm's reach for night feeds and settling, but on their own safe surface with their own firm mattress and no soft bedding. The AAP recommends room-sharing for at least the first six months and ideally through the first year. UK NHS guidance is consistent. Evidence shows room-sharing reduces SIDS risk compared to a separate-room arrangement.

Bedside bassinet or sidecar cot. A bedside bassinet (culla a fianco in Italian) is a small cot that attaches or sits flush against the parent's bed at the same height, with one open side facing the parent. The baby has their own firm, separate surface, but is immediately adjacent and reachable for feeding. Many families find this arrangement gives them the closeness and convenience of bedsharing without the highest-risk elements. Sidecar cot arrangements (a standard cot with one side removed and secured to the bed frame at matching height) work similarly.

If bedsharing does happen, reduce the risk. Many parents who intend not to bedshare find themselves doing so, particularly during recovery from birth or during growth spurts when a baby feeds very frequently. The UNICEF UK evidence review, NHS guidance, and organisations like Red Nose in Australia all acknowledge this reality and provide harm-reduction advice for when bedsharing occurs: use a firm, flat mattress (not a waterbed or memory foam); keep duvets, pillows, and soft toys away from the baby; do not let the baby sleep between two adults; ensure the baby cannot fall off the bed or become wedged against the wall; do not wear clothing with cords or ties; do not swaddle the baby while bedsharing. If you have consumed alcohol or taken any sedating medication, or if you smoke, do not bedshare.

Carry contact through the day. Many families find that generous physical contact during the day, through babywearing, skin-to-skin time, and being held during feeds and naps, reduces a baby's need to be physically adjacent during night sleep. This is not a universal solution, but it is worth knowing.

Having the conversation with your family

If you were raised in a culture where il lettone or its equivalent was simply normal, you may face pressure from grandparents who cannot understand why you would do things differently. You may also face pressure in the opposite direction, from friends or health visitors who assume you share the Western medical default. Both pressures are real, and both deserve a calm response.

When grandparents and nonne expect the family bed, a few things are worth remembering. First, they are usually expressing love and closeness, not deliberately undermining your safety decisions. Second, the risk factors they did not know about (sofa sleeping, alcohol, smoking near a baby) were also less clearly understood a generation ago, not because parents were negligent, but because the research was not yet as developed. Third, you are allowed to make different choices without it being a rejection of how they raised their children.

Being specific tends to work better than being abstract. Rather than saying "the guidelines say bedsharing is dangerous," try: "We are doing room-sharing, so the baby is right next to our bed all night and I can reach them instantly. It is working really well for night feeds." This describes what you are actually doing, frames it positively, and does not require your relatives to agree that what they did was wrong.

If a grandparent wants to care for the baby overnight, be direct about the specific arrangements you need: firm surface, no duvets, no sofa settling. Write it down if that helps. Frame it as information sharing, not instruction. Most grandparents who understand that you are asking for specific things rather than criticising their general approach are very willing to accommodate.

Ultimately, where your baby sleeps is your decision, shaped by your circumstances, your risk factors, your home environment, and your values. You do not owe anyone a defence of that decision. You do deserve to have good information to make it.

Frequently asked questions

Is bedsharing always dangerous?
Bedsharing carries the highest risk on soft surfaces (sofas, armchairs), when either parent has consumed alcohol or sedating drugs, or when the baby was born premature or at low birthweight. In lower-risk settings, on a firm flat mattress, with no duvets near the baby and no smoking in the household, the absolute risk is much smaller, though it is never zero. The safest sleep surface for a baby remains a firm, flat, separate surface in the same room as a caregiver.
How long should my baby sleep in my room?
The American Academy of Pediatrics recommends room-sharing (baby on a separate surface in the same room) for at least the first six months, and ideally for the first year. UK NHS guidance is consistent with this. Room-sharing reduces SIDS risk compared to sleeping in a separate room.
What is a sidecar cot arrangement?
A sidecar cot is a cot or bassinet placed right beside the parent's bed, with one side removed or lowered so the sleeping surfaces are level and adjacent. The baby has their own firm, flat surface and their own bedding, but is within arm's reach for feeding and comfort. It provides proximity without the risks of sharing a duvet, pillow or soft mattress.
My parents and in-laws expect the baby to sleep in our bed. How do we handle that?
You are allowed to make a different choice from the previous generation. Be specific rather than critical: explain what you are doing (room-sharing with a bedside cot) and why you find it works for your family, without framing it as a verdict on how older relatives raised their children. Offering a concrete alternative, such as a grandparent settling the baby in their own room during daytime naps, often satisfies the closeness that grandparents are really seeking.

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