Bed-sharing: what the evidence actually says

Bed-sharing is one of the most contentious topics in infant safe sleep, partly because major health organisations do not say the same thing. The AAP, NHS, and The Lullaby Trust each take a meaningfully different position — not because they're looking at different evidence, but because they've made different judgements about how to communicate risk to parents.

Understanding all three frameworks lets you make an informed decision. This article presents each position fairly, cites the source for each, and then covers the specific scenarios where risk is highest.

The AAP position: do not bed-share

The AAP's 2022 sleep guidelines state clearly that bed-sharing is not recommended — and this applies regardless of whether the parents smoke, drink, or have other risk factors.¹

The AAP reaches this position because:

• The absolute number of sleep-related infant deaths remains significant, and a proportion occur in bed-sharing scenarios even where specific risk factors (smoking, alcohol) are absent
• Standard adult sleep surfaces — mattresses with pillows, duvets, soft toppers — are not designed for infant safety
• There is no scenario in which the AAP judges the adult bed to be an equivalent or safer surface to a firm, flat infant sleep space

The AAP's position is that the protective benefits of room sharing are achievable without bed-sharing, and therefore the risk-benefit calculation does not support recommending it under any circumstances.¹

The NHS position: specific risk factors determine the risk level

The NHS takes a conditional approach.² The NHS guidance says: do not share a bed with your baby if:

• You or your partner smoke (even if you don't smoke in the bedroom — smoke residue on clothing carries risk)
• You or your partner have recently drunk alcohol
• You or your partner have taken drugs or medication that makes you drowsy
• Your baby was premature (born before 37 weeks)
• Your baby had a low birth weight (under 2.5 kg / 5.5 lb)

The NHS explicitly adds that if none of these risk factors apply, the risk of bed-sharing is lower — though it remains present, and room sharing is still recommended as safer.²

This framing differs from the AAP's in a meaningful way: the NHS is quantifying risk by risk factor rather than issuing a blanket recommendation. For a non-smoking couple who have not drunk alcohol, with a full-term healthy baby, the NHS does not characterise bed-sharing in the same terms as the AAP.

The Lullaby Trust position: harm reduction

The Lullaby Trust takes the most explicit harm-reduction approach of the three.³ Their position acknowledges that some families will bed-share regardless of guidance, and that providing specific safer-sleep information for those situations reduces risk.

The Lullaby Trust identifies the same high-risk factors as the NHS — smoking, alcohol, drugs/sedating medication, prematurity, low birth weight — and frames them as factors that make bed-sharing dangerous rather than merely inadvisable. For families who have none of these risk factors and choose to bed-share, the Lullaby Trust provides guidance on how to do so more safely:

• Use a firm mattress, not a soft topper or waterbed
• Keep duvets, pillows, and soft bedding away from the baby
• Make sure the baby cannot fall out of the bed or become trapped between the mattress and wall
• Place the baby on their back
• Do not swaddle while bed-sharing

The Lullaby Trust's approach is shaped by the reality of clinical practice: health visitors, midwives, and GPs encounter families who are bed-sharing, and harm-reduction guidance is more useful to those families than a flat "don't do it."

One thing all three agree on: sofas and armchairs are the highest risk

Whatever their differences on adult-bed sharing, the AAP, NHS, and Lullaby Trust are unanimous on one point: sleeping with a baby on a sofa or armchair is the most dangerous infant sleep scenario.¹²³

The risk is a combination of factors: the surfaces are soft and enveloping, babies can slip into position between a cushion and an armchair arm, and adults falling asleep in a seated position may shift. The SIDS and accidental sleep-related death rates associated with sofa and armchair sharing are substantially higher than those for any form of bed sharing.

Putting it together: what does this mean in practice?

The clearest read on the evidence:

1. No risk factors are zero-risk. Even in the most favourable scenario (non-smoking, no alcohol, healthy full-term baby, firm mattress, no soft bedding), the adult bed is not as safe as a separate infant sleep surface. The AAP's flat "no" reflects this.

2. Risk factors multiply the risk substantially. Smoking in the household raises the risk dramatically. Alcohol, drugs, or sedating medication do the same. Prematurity and low birth weight reduce the infant's physiological resilience. When these factors are present, all three frameworks agree: do not share a bed.

3. Planning for accidental bed-sharing reduces harm. Most bed-sharing happens because a parent falls asleep during a night feed. Having a plan — moving to a firm surface, removing duvets from the baby's area, placing the baby on their back — is more useful than pretending it won't happen.

Room sharing, on a separate firm surface, remains the recommendation of all three frameworks. That recommendation is the one with clear protective benefit and no meaningful downside.

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Sources

1. American Academy of Pediatrics. "Sleep-Related Infant Deaths: Updated 2022 Recommendations for Reducing Infant Deaths in the Sleep Environment." Pediatrics 150(1), 2022. https://publications.aap.org/pediatrics/article/150/1/e2022057990/188304/Sleep-Related-Infant-Deaths-Updated-2022-Recommendations
2. NHS. "Reduce the Risk of Sudden Infant Death Syndrome (SIDS)." NHS, 2024. https://www.nhs.uk/conditions/baby/caring-for-a-newborn/reduce-the-risk-of-sudden-infant-death-syndrome/
3. The Lullaby Trust. "Bed-sharing and co-sleeping." 2024. https://www.lullabytrust.org.uk/safer-sleep-advice/bed-sharing/