Co-sleeping is when a parent or carer sleeps with a baby on a bed, sofa, or chair, and is associated with increased SIDS risk in certain circumstances.
The Lullaby Trust defines co-sleeping as "when parents or carers sleep with a baby on a bed, sofa or chair." Within this, bed-sharing refers specifically to a baby sharing a bed with an adult for most of the night, while room-sharing — where the baby sleeps in the same room but in a separate sleep space — is a distinct and safer arrangement. The Lullaby Trust states that "the safest place for a baby to sleep is in their own separate sleep space such as a cot or Moses basket, free from toys, blankets and pillows."
What does the guidance say about co-sleeping risk?
The Lullaby Trust reports that "around half of sudden infant death syndrome (SIDS) deaths happen whilst co-sleeping, and most of these occur in high risk situations." The NHS advises keeping babies in a "separate cot or Moses basket in the same room" as the primary caregiver, noting that co-sleeping carries significantly higher risk in specific circumstances.
When is co-sleeping particularly dangerous?
Both the Lullaby Trust and the NHS identify circumstances in which co-sleeping substantially raises SIDS risk. These include: when anyone in the bed smokes (or the baby was exposed to smoke prenatally); when anyone in the bed has consumed alcohol; when anyone in the bed has taken sedating medications or drugs; and when the baby was born prematurely (before 37 weeks) or had a low birth weight (under 2.5 kg / 5.5 lb). The Lullaby Trust states: "Never fall asleep on a sofa or armchair with your baby as it significantly increases their risk of SIDS."
What precautions apply when bed-sharing does occur?
The Lullaby Trust advises that when a parent does share a bed with a baby, they should keep pillows and adult bedding away from the baby, ensure the baby cannot be trapped between the mattress and wall, remove slatted or decorated headboards, use a fitted baby sleeping bag rather than loose adult bedding, and never leave the baby alone in an adult bed. UNICEF UK's Baby Friendly Initiative emphasises a "sensible, proportionate and parent-centred approach" to discussing co-sleeping with families, acknowledging that around half of all parents will sleep with their baby at some point.
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