A blog by Dr Lin Day

Co-sleeping – Benefits and Risks

All young mammals stay in close proximity with the mother, and human babies are no exception. In some cultures, the practice of sleeping with the baby is still common, but in others, co-sleeping has been abandoned in favour of cots, cribs or cradles. In some homes, the baby may sleep in a room separate from the mother, which is a risk factor for Sudden Infant Death Syndrome (SIDS) – if the baby is less than 6 months-old.

Co-sleeping lost favour in the 13th century, when Catholic priests in Europe recommended that mothers should stop the practice for fear of smothering their babies. In the 20th century, babies were separated from their mothers in hospitals to protect them from infections. Other influences such as internet publications and the decline in breastfeeding have contributed to separation.

About 30% of babies share the parental bed at some point during the night. Many mums-to-be, who do not intend to bed-share, nevertheless do so after the birth. Bed-sharing is more widely accepted today, although the practice has its critics.

Benefits of co-sleeping

  • Helps the baby to fall asleep more easily.
  • Regulates the baby’s breathing patterns and body temperature.
  • Promotes bonding.
  • Enhances the physiological and psychological well-being of the baby and parent.
  • Provides security and comfort of body contact with the mother throughout the night.
  • Enables the mother to monitor the baby’s well-being.
  • Reduces stress for the parents.
  • Convenient night time breastfeeding for the mother and baby.
  • Less crying at night.

Even though the mother sleeps more lightly, she is more likely to gain a restful night’s sleep.

Both parents should feel comfortable with the decision to co-sleep, agree that they are equally responsible for the baby, and acknowledge that the baby is present.  Parents should not face disapproval if they have found co-sleeping to be an effective option.

Sidecar or bed nest

If co-sleeping does not work for one or both parents, a sidecar or bed nest placed against the parental bed, can provide an alternative. However, the side panel should always be lowered or removed so that the mother and baby have easy access to each other.

There must not be a gap or ridge between the parental bed and the sidecar or bed nest. Recently, a 7-week-old baby died of asphyxiation after manoeuvring herself over a ‘safety ridge’ on one side of the bed nest.

Risks of co-sleeping

Although there is an association between co-sleeping and SIDS, evidence suggests that it is not co-sleeping that is the risk factor, but the circumstances in which it occurs. For example:

  • If the baby is premature or of low birth weight.
  • Parental alcohol consumption.
  • Parental overtiredness or exhaustion.
  • Taking drugs or medications in the hours leading up to co-sleeping.
  • If one or both parents are smokers.
  • If the parent suffers from sleep deprivation.
  • Sleeping on a sofa or armchair, with or without the parent. The baby may slip face down into the crevice or get wedged at the back of the chair.
  • Leaving the baby in the parental bed alone.
  • Getting stuck between the mattress and the wall or furniture.
  • Falling out of the parental bed.
  • Suffocating on a waterbed, soft mattress, soft bedding (pillows, blankets, quilts, etc.).
  • Getting entangled in the mother’s hair if it is excessively long.

The mattress must be flat, firm and smooth. A soft surface such as a waterbed, sofa, beanbag or any other flexible and yielding structure increases the risk of SIDS. There must be no space between the mattress and the wall or furniture where the baby could become stuck. There must be no loose blankets or pillows that could obstruct the baby’s breathing.

An alternative is to place the mattress on the floor, making sure there are no crevices that the baby could become wedged in.

Ideally, the baby should sleep on the mother’s side of the bed. Research shows that fathers are less attuned to the baby’s movements and more likely to roll on top of them.

Co-sleeping is not recommended for formula fed babies because it is thought that the mother may not arouse as easily as the breastfeeding mother. However, more research is needed to substantiate this.

 Safety and SIDS

The practice of co-sleeping has benefits and risks. The American Academy of Pediatrics warns that the risk of SIDS increases when babies co-sleep with parents who smoke or are intoxicated by alcohol, drugs, medications or sedatives.

 The following may also increase the risk of SIDS:

  1. Sleeping in the prone (tummy) or side position.
  2. Overheating.
  3. Chilling.
  4. Unfamiliar sleeping conditions.
  5. Covering the baby’s head or face.
  6. Mattress and bedding.
  7. Environmental smoke.

In the absence of hazardous circumstances, the number of co-sleeping SIDS deaths is no more than expected in the general population, in fact slightly less.

 What the experts say

Popular parenting magazines and the media have tried to discourage parents from co-sleeping with their baby because of the risk of SIDS. According to the Academy of Breastfeeding Medicine, there is currently not enough evidence to recommend against co-sleeping. In fact, co-sleeping is probably safer than sleeping alone (providing there are no risk factors), because the baby spends more time sleeping on his or her back.

Research shows that the SIDS rate is lowest (and even unheard of) in countries where co-sleeping is normal practice. Information published by the Consumer Product Safety Commission showed more than 3 times as many crib-related infant fatalities compared to co-sleeping accidents.

The Department of Health advises that the safest way for the baby to sleep is on his or her back in a cot with both sides fully up and secure in the parents room for the first 6 months. Back-sleeping continues to have a significant effect on reducing SIDS.


Visit: www.babysensory.com to discover more about you and your growing baby.

The Lullaby Trust provides expert advice on safe sleep for babies and raises awareness of SIDS. Tel: 0808 802 6869; web:www.lullabytrust.org.uk

Comments (2) -

  • Dr Lin Day

    11/10/2015 10:34:27 PM | Reply

    Thank you very much for your comment and for reading the blog. You have clearly taken every precaution to keep your twin babies safe.

    I co-slept with each of my 4 children, 3 of whom were breastfed. My instinct was always to be close to my baby.
    There is evidence to suggest that bottle-fed babies are not as easily aroused as breastfed babies during deep sleep – the peak SIDS risk period in the first 2 to 3 months. Evidence also suggests that the smell of breast milk contributes to longer periods of light sleep and that it prevents the baby from roaming and getting stuck. Data from the Consumer Product Safety Commission indicates that the greatest risk to co-sleeping is not, as many would assume, from the parent rolling over onto the baby, but from suffocation (e.g. becoming wedged or trapped between the mattress and a piece of furniture or from lying face down on a waterbed or soft mattress).
    You can read all this on online:

    Thanks again and I hope this answers your question!

    Dr Lin Day

  • Mrs Ms

    11/10/2015 10:36:17 PM | Reply

    Really sad to see the formula fed comment. I didn’t breastfeed my twins for more than a few days and have had no problems sleeping next to them, just make sure there aren’t any obvious dangers like pillows or duvets etc They love it and so do I, never once faced or rolled away from them. Breastfeeding mums are known to roll onto their babies.