Room sharing: how long, and how it reduces SIDS risk

Room sharing with your baby reduces SIDS risk by as much as 50%, according to AAP estimates.¹ It's one of the few safe sleep practices that costs nothing, requires no equipment, and has strong agreement across different health systems. The catch: it only works if your baby has their own sleep surface in the room. Room sharing is protective. Bed sharing is not.

The recommendations

AAP (US): Room share — with your baby sleeping on a separate, firm surface — for at least the first 6 months of life, ideally for the full first year.¹

NHS (UK): Share a room with your baby for the first 6 months for every sleep, including daytime naps.²

These recommendations come from different health systems that don't always align on parenting guidance. On room sharing, they do. The evidence base is consistent enough that both systems have maintained this recommendation through multiple guideline updates.

Why it works

The protective mechanism isn't fully understood, but the leading theories have good support:

Arousal and proximity. When a parent is sleeping nearby, minor sounds and movements from the baby are more likely to rouse them. Parental proximity may also influence the baby's own arousal patterns — there is some evidence that infant-parent sleep in close proximity is associated with lighter, more responsive sleep in both.¹

Easier feeding. Breastfeeding independently reduces SIDS risk — the AAP cites a roughly 50% reduction for consistently breastfed infants.¹ When a baby is within arm's reach, night feeds happen more easily and more frequently, which supports both supply and the feeding relationship.

Faster response. If something does go wrong, a parent in the same room can respond in seconds rather than minutes.

Room sharing ≠ bed sharing

This distinction is the most important thing in this article.

Room sharing: your baby sleeps in the same room as you, on their own firm, flat sleep surface (cot, crib, bassinet, or Moses basket). You are nearby. Baby is separate.

Bed sharing: your baby shares your bed — the same mattress, the same sleep surface — with you or another adult.

Bed sharing significantly increases SIDS risk in most circumstances. The AAP explicitly states that bed sharing should not be practised with infants in normal circumstances.¹ The NHS agrees.² The increased risk is greatest when:

• The parent smokes (including outdoors — smoke on clothing carries risk)
• Either parent has consumed alcohol
• Either parent takes sedating medication
• The mattress is soft, or pillows and duvets are present
• Multiple people are sharing the bed with the infant

Even for parents who don't smoke and don't drink, a standard adult bed with a duvet is not a safe infant sleep surface.

The accidental bed share. Many parents fall asleep with their baby during a night feed — in bed, on a sofa, in an armchair. Planning for this reduces its danger. If you think you might fall asleep during a feed, move to a firm surface first. Sofas and armchairs are the highest-risk environments for infant sleep, not because of intent but because of the surface.¹

Safe room-sharing setups

Bedside crib. Attaches to the adult bed at the same mattress height. Baby has their own firm surface; you can reach them without getting up. The most convenient setup for night feeds.

Standalone bassinet or Moses basket. In the room, within a couple of steps. Suitable for the first 3–6 months, until the baby outgrows it or starts rolling.

Full-size cot. In the room. Further from the adult bed but still fulfils the room-sharing recommendation. Move the cot if possible rather than the baby to a different room.

Sidecar arrangement. One side of the cot lowered (where the design allows) and positioned flush against the adult bed. Baby has their own firm surface with access to parents; effectively a bedside crib. Check that there is no gap between the cot mattress and the adult mattress.

Whatever the setup: baby's sleep surface must be firm and flat, with no loose bedding, bumpers, pillows, or soft objects.

When to move your baby to their own room

No fixed rule — the guidance says after 6 months, and the AAP extends that to ideally 12 months. SIDS risk naturally falls significantly after 6 months and is very low by 12 months regardless of sleep arrangement.

Most families make the transition somewhere between 6 and 12 months, often driven by everyone sleeping better when separated rather than by a strict guideline. There is no evidence that staying in the same room past 12 months causes harm; the recommendation has a floor, not a ceiling.

← Back to the complete guide: Safe sleep and newborn sleep

Also in this cluster: Back to sleep · What to put in the cot

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. "Safer Sleep Advice." 2024. https://www.lullabytrust.org.uk/safer-sleep-advice/