Should I let my baby sleep in the car seat?

Our helpful guide explains what you need to know about the safety aspect of babies sleeping in car seats

The rules to follow if your baby sleeps in the car seat

Understanding the safety aspects of babies sleeping in a car seat


Babies sleep a lot, particularly newborns, and it’s not always possible to stay at home all day to ensure every nap is lying flat on their back in their cot or Moses basket - as the experts recommend. 

Inevitably trips to the supermarket, the school run and the in-laws have to be taken and the soothing lull of the car engine is often enough to send even the most alert baby into dreamland. Many new parents worry about their little one nodding

Worrying studies

Studies on the subject do little to quell the fears. A US study published in 2015 by the Journal of Paediatrics found that ‘sitting devices’ like car seats - as well as swings, and bouncers - can lead to injury and even death if babies are allowed sleep in them.

Because their airways are still developing, young infants are at risk of suffocation when their bodies become scrunched up, making it hard for them to breathe. 

The Lullaby Trust, which is dedicated to preventing sudden infant deaths, wants further research to be carried out on the back of this latest study. It says it recognises the important role that car seats play in transporting a baby safely from A to B but stipulates that they should not be used for extended periods or as a sleeping device outside the car. 

It says small babies do not have the ability to support their heads and this study shows being upright in a seat is a risky position for a long period of time.

So, is it OK for baby to sleep in a car seat?

The hard and fast rule is not to panic if your little one nods off in the car. It’s impossible to avoid all journeys and it’s difficult to ensure that all their naps are in their cots. As long as the baby is healthy, a short snooze in a car seat should not be a cause for concern as long as you take some simple precautions.

If so, for how long? 

Experts recommend keeping the journey as short as possible - and the general rule of thumb is they shouldn't sleep in car seats for long periods of time. The two-hour guide applies to babies who are not yet able to sit up unsupported. New babies will slump in the car seat and research shows that this poor posture can mean that their lungs are not expanding fully, reducing the amount of oxygen in their blood. There are also implications for a baby’s spine. Check the car seat’s manufacturer’s guidelines for safe travel. 

What safety aspects do you need to be aware of?

  • Avoid long journeys, where possible. If you need to undertake a longer journey, stop for a break and take the baby out of the car seat for a cuddle and a feed. You’ll probably be glad of a coffee after two hours’ driving anyway.
  • Do your research and invest in a safe and good quality car seat. Many gadgets marketed at new babies are unnecessary, but a good quality car seat is not an area to scrimp on. There are lie-flat models which can be considered if you do a lot of travelling. 
  • It sounds obvious but only use the car seat while in the car. When you get home, it can be tempting to allow the baby to continue their sleep but it’s safer to transfer him or her to the cot or Moses basket.
  • Keep an eye on the temperature in the car and make sure the baby is not too hot or wearing too many clothes. Heavy coats should not be worn in car seats.
  • Make sure you can see the baby at all times. There are mirrors that can be safely attached if there are just the two of you travelling.

Premature and low birth weight babies 

The Lullaby Trust warns that premature babies before (37 weeks) or of low birth weight (under 2.5kg) are even more at risk of breathing difficulties when in a car seat for a long time. Some babies may have a ‘car seat challenge’ before they go home from hospital to check if they fit properly in their car seat. Many car seats aren’t lie-flat, which can mean smaller babies are slumped over making it harder for them to breathe more easily. 

On longer journeys, give your baby regular breaks to take them out of the car seat. If possible, have an adult sit with the baby in the back of the car, or use a mirror so you are able to keep an eye on them. 

Above all, babies should not sleep in car seats when not travelling.  For further information visit

Should I let my baby sleep in the car seat?