If a child is struggling to breathe, is floppy or will not wake, or their skin, lips or tongue look blue or grey: call 999 now. Colour changes are harder to see on brown and black skin, so check the palms, soles, lips and tongue. If you are worried but it is not an emergency, call NHS 111. In Northern Ireland use your GP out-of-hours service.

MarionSleep help for families

Co-sleeping and bed-sharing

When it is genuinely dangerous, and how to make a bed safer in advance.

The short version

  • Never fall asleep on a sofa or armchair with your baby: they can slip into a position where they are trapped and cannot breathe.
  • If you fall asleep with your baby, you are much safer in a bed than on a sofa or chair.
  • Do not share a bed if anyone in it has had any alcohol, smokes or vapes, or has taken anything that makes them sleepy.
  • Do not bed-share if your baby was born before 37 weeks or weighed under 2.5kg. If that applies, they sleep in their own cot.
  • Prepare the bed while awake: adult bedding away, no gaps at headboard or edges, your baby on their back, no other children or pets.
  • Never leave your baby alone in an adult bed. If you get up, take them with you or move them to their cot.

The rest of this page explains where this comes from. You do not have to read it tonight.

About 6 minutes to read

Co-sleeping and bed-sharing

Co-sleeping means your baby sleeping on the same surface as you: a bed, a sofa or a chair. Bed-sharing means specifically in a bed. The difference between those two is the most important thing on this page, and UK guidance is deliberately not "never co-sleep."

UNICEF UK's guide for health professionals explains why: "Young babies wake frequently at night and need to be fed and cared for somewhere. In most homes this will be in bed or on a sofa or armchair, simply because there is no other comfortable place. Parents can easily choose the more dangerous sofa over the less dangerous bed because they are trying to follow advice to never bed-share."

And the line every exhausted parent should know: "If parents fall asleep with their baby they are much safer in a bed than on a sofa or chair." UNICEF adds that "shocking messages that imply that all/any co-sleeping leads to death are not helpful. They do not reflect the evidence." So this page is specific instead.

When sharing a sleep surface is genuinely dangerous

Never fall asleep on a sofa or armchair with your baby. The Lullaby Trust: it "significantly increases their risk of SIDS", because babies "can easily slip into a position where they are trapped and can't breathe." If you are feeding on the sofa at night and might drop off, put your baby down in their cot first, or move to the bed.

Do not share a bed with your baby if:

  • You or anyone else in the bed has recently drunk any alcohol.
  • You or anyone else in the bed smokes or vapes, or your baby was exposed to smoking in pregnancy.
  • You or anyone else in the bed has taken any drugs or medication that make you feel sleepy, prescribed or over the counter.
  • Your baby was born before 37 weeks or weighed under 2.5kg (5½lb). For premature babies the Lullaby Trust advises avoiding co-sleeping completely until one year from the due date.

These are not "less ideal". They are the circumstances in which babies die. If any apply tonight, your baby sleeps in their own cot.

The actual numbers

Multipliers ("x times the risk") sound terrifying and tell you almost nothing, because they hide what they are multiplying. These are the absolute figures from UNICEF UK, using 2017 data for England and Wales.

Risk of SIDS in different situations. Source: UNICEF UK Baby Friendly Initiative, Co-sleeping and SIDS: A Guide for Health Professionals, last updated October 2019.
SituationRisk of SIDS
All babies, England and Wales1 in 3,710
Co-sleeping on a sofa1 in 203
Co-sleeping after alcohol or drugs1 in 203
Co-sleeping with a regular smoker1 in 919

The hazards carry the risk. A sofa and drink or drugs sit equally high in that table. UNICEF adds that around half of the babies who die of SIDS die while co-sleeping, but "90% of these babies died in hazardous situations which are largely preventable". That 90% is why this section exists.

The "50 times" figure, and what the research actually found

You may see the claim that sofa-sharing raises the risk "by up to 50 times". That comes from the Lullaby Trust, not from a research paper, and the peer-reviewed UK study gives a lower number: Blair and colleagues, PLOS ONE 2014, found an odds ratio of 18.3 for sofa-sharing (95% confidence interval 7.1 to 47.4). We have used the absolute risks above instead.

The same study found bed-sharing without the hazards listed above was not associated with a significant increase in risk (odds ratio 1.1, 95% confidence interval 0.6 to 2.0), while the hazards carried large risks. The authors concluded that blanket prohibition "negates the option of highlighting the specific and highly significant risks we have found."

Making the bed safer, in case you fall asleep

In a Lullaby Trust survey of over 3,400 new parents, more than 40% said they had fallen asleep on a sofa or armchair with their baby, and over half had fallen asleep in bed unintentionally. Only 4 in 10 had been given any co-sleeping safety advice. If this has happened to you, you are in the majority, and the useful response is to prepare rather than promise yourself it will not happen again.

The Lullaby Trust says so directly: "If you feel you might fall asleep, we recommend you prepare the bed to make it safer for baby." Do it while you are awake and thinking clearly, before the evening starts.

  1. Check the hazards first Run through the four circumstances under When sharing a sleep surface is genuinely dangerous above. If any apply, the plan is a cot beside the bed instead.
  2. Move the pillows and adult bedding away Nothing near your baby's head.
  3. Deal with the headboard and bedframe Remove slatted or decorated headboards. Check your baby cannot get wedged in the frame, or between the mattress and the headboard or wall.
  4. Check the edges Make sure your baby cannot roll or fall out.
  5. Baby on their back on the flat mattress Not on a pillow, not propped, and not swaddled.
  6. No one else in the bed No other children and no pets. Other children move in their sleep and do not understand they need to keep clear.
  7. Never leave your baby alone in an adult bed If you get up, take them with you or move them to their cot.
A bed prepared for a baby, seen from above An adult bed viewed from above. An adult lies on the right hand side with a pillow beside their head, and the duvet folded down at the foot of the bed on their side only. The baby lies on its back to the left of the adult, with no pillow or bedding near it, and a marked clear gap between the baby and the edge of the bed.
A bed prepared in case you fall asleep: baby on their back on the flat mattress, no pillow or adult bedding near them, your duvet kept low and on your side, and a clear gap so they cannot fall out or become wedged.

If you are on your own at night

The fourth headline message, that babies need a sober carer, reads like advice for couples. It is not. If you are the only adult in the house, you make the plan in advance: no alcohol and no sedating medication on the nights you are on duty, the bed prepared before the evening starts, and your baby's cot within arm's reach of where you feed. If you do drink, the Lullaby Trust's advice is to have "a trusted sober adult around who can care for your baby", arranged beforehand rather than hoped for. There is more on getting through the nights on our page about looking after yourself.

Where this comes from

Last checked 1 August 2026. This page is general information, not medical advice. If you are worried about your child, speak to your health visitor or GP.