Co-sleeping — sharing a sleep surface with a newborn — is common in many families and cultures. It is important to approach this topic with clear information rather than blanket prohibition or dismissal. The evidence on risk is substantial, and the specific risk factors that increase risk are well-identified. Making an informed decision requires understanding both.
Healthbooq provides accurate, evidence-grounded guidance on infant safe sleep.
The Evidence on Risk
Research consistently identifies bed-sharing — sharing a bed (not just a room) with a newborn — as a risk factor for SIDS and suffocation, particularly in infants under 3 months. The Lullaby Trust (UK) and the NHS recommend that babies sleep in their own sleep space in the parents' room for the first six months.
The risk is not uniform. Several factors substantially increase the risk of bed-sharing:
High-risk factors for bed-sharing:- Either parent is a smoker (regardless of whether they smoke in the bedroom)
- Either parent has consumed alcohol
- Either parent has taken medication or substances that cause drowsiness
- The baby was born prematurely (before 37 weeks)
- The baby had a low birth weight (under 2.5 kg)
- The parent is extremely tired
In the presence of any of these factors, bed-sharing is strongly contraindicated.
The "Never Sleep on a Sofa or Chair" Rule
Falling asleep with a baby on a sofa, armchair, or recliner is significantly more dangerous than bed-sharing. The Lullaby Trust identifies sofa-sharing as carrying much higher risk than bed-sharing. If there is a risk that a parent might fall asleep while feeding, the safer option is to plan for feeding in bed (with attention to bedding and positioning) rather than on a sofa.
Room-Sharing vs. Bed-Sharing
Room-sharing — placing the baby's cot or Moses basket in the parents' bedroom — reduces SIDS risk by approximately 50% compared to the baby sleeping in a separate room. This is the recommended arrangement for the first six months.
Bed-sharing provides proximity benefits (easier night feeding, potential maternal-infant physiological regulation) but introduces the risks described above.
Safer Bed-Sharing Practices (When Bed-Sharing Occurs)
When bed-sharing occurs despite the risks:
- Place the baby on their back (never prone or side-lying on a shared surface)
- Keep heavy duvets, pillows, and blankets away from the baby
- Do not swaddle the baby for bed-sharing
- Ensure the baby cannot roll into a gap between the mattress and wall
- Never place the baby between two adults
Key Takeaways
Co-sleeping (sharing a sleep surface) with a newborn carries significant risks of Sudden Infant Death Syndrome (SIDS) and accidental suffocation, particularly in the presence of specific risk factors. The NHS and Lullaby Trust advise that the safest place for a baby to sleep is in their own sleep space (cot, Moses basket) in the parents' bedroom for the first six months. Bed-sharing is strongly contraindicated if the parent smokes, has consumed alcohol, has taken sedating medication, or is very tired.
