Car seats are, on the whole, very secure, essential pieces of baby gear, for keeping our children safe when travelling in a vehicle.


But only when they're used correctly. And sadly, car seats and, by extension travel systems, are sometimes used for too long or for general sleeping, leading to some devastating consequences.

Between 2004 and 2008, a total of 31 children under the age of 2 died due to suffocation or strangulation while sitting in a car seat for extended periods of time, according to a 2015 study published in the Journal of Pediatrics.

The Penn State Medical Centre report says children as young as 1 month had either suffocated or been strangled by the straps of their car seats. In the image above, you can see how a small baby can easily wriggle out of car seat straps if they're not tightened correctly.

What the research says:

A study (October 2016) funded by the Lullaby Trust and conducted by an NHS Foundation Trust and University of Southampton, has also recommended parents do not keep infants or babies in car seats for long periods of time.

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That's because as well as being in a scrunched position, the movement of the car while travelling also has an impact on babies while in car seats. Previously, safety tests did not take into account the angle a seat will take while in a car or the vibrations of the seat while in motion.

Using a motion simulator (and 40 babies in the car seats) they replicated a 30mph car journey to reproduce vertical vibration - similar to that at the base of a car safety seat in a rear-facing position in the back of a small family car.

The study revealed that movement and an upright position of 40 degrees, significantly increased heart and respiratory rates, and decreased oxygen saturation, leading to an “increase in potentially clinically significant oxygen desaturations.”

Of course the experts aren’t saying we should ditch car seats, but they are once again warning against keeping babies in a car seat for too long, especially while sleeping.

“Parents should not stop using car safety seats to transport their infants. Infants must be protected in moving vehicles, and UK law requires car seats be used whenever infants travel in cars,” says consultant Paediatrician of the Great Western Hospitals NHS Foundation Trust, Dr Renu Arya.

“However, our findings support the AAP (American Academy of Paediatrics’) guideline that infant car seats should not be used as a routine infant sleep environment.”

It's important not to get over-anxious about your baby sitting in a car seat. These are still small numbers. The key message is that car seats are for travelling, cribs and cots are for sleeping. It's really about knowing the safety advice.

Does it effects newborn infants differently?

Reports (some worrying) in the mainstream media questioned whether newborn babies are safe if they sit in a car seat for just 30 minutes.

The research (November 2016) carried out by researchers at Swindon's Great Western Hospital, the University of Southampton and the University of Bristol and commissioned by the Lullaby Trust found that when newborn or premature babies sat in a car seat for 30 minutes, their heart and breathing rate increased, and their blood oxygen levels were lower compared with lying flat in a cot.

This happened when the babies were both stationary in the car seat and 'moving' in the car simulator and these effects were more marked with premature babies but still seen with term babies.

Here's the full story

The two hour 'rule'

The '2 hour rule' is the established safety recommendation endorsed by safety experts and manufacturers, that suggests children shouldn't sit in a car seat for more than 2 hours at a time. That's not only when your baby's in a car but also when they're in a travel system (pictured above) - a buggy chassis with a car seat attached.

The reason, as we explained above, is that babies and very young children can experience breathing problems if placed in a seated or scrunched position for too long.

“Car seats are desperately important to save lives from car accidents. However, families should not leave babies in car seats for long periods or once they are removed from the car,” explains Justin Daniels from the Lullaby Trust.

“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.”

The safest way for babies to sleep is on their backs - as recommended by the experts at the Lullaby Trust.

It's best if they are on a firm, flat, waterproof mattress in a separate cot or Moses basket for at least the first 6 months.This is because your baby’s ability to keep their head held up is not fully developed, meaning their head can flop down and restrict the airways.

Read: How to stop your child wriggling out of car seat straps

So to keep your baby safe:

  • Ensure your baby is not sitting for more than a couple of hours in the same upright position
  • Don't use a car seat as an alternative to a cot or crib - as a regular place to sleep (although obviously don't worry if your baby falls asleep in your car, as most babies do! You just don't want them sleeping for more than two hours in the same position)
  • If you're travelling on a long car journey, stop for a little bit and take your baby out of the car seat
  • If you're using a travel system, don't keep your baby in the car seat for more than the two hours. If you know your baby is going to be in the travel system for a longer period, use a carrycot or lie-flat seat rather than the car seat

Lie-flat car seats

There are two types of car seats that can help solve this issue:

A converting lie-flat car seat - such as the Jane Matrix 2 (pictured above) or the Kiddy Evo-Lunafix, is a car seat that will keep your baby upright in the car, but then can be converted to a lie-flat position on a travel system or at home.

A permanent lie-flat car seat/carrycot - such as the Britax Baby Safe Sleeper or the Jane Transporter 2, lets your baby lie flat in the car and is also a carrycot suitable for overnight sleeping

Read: Why your newborn needs a lie-flat buggy

Read: 6 of the best lie-flat car seats from birth

Beware with slings, bouncers, swings and buggies too

It isn’t only car seats posing a small risk to sleeping children, according to the report.

In total, 47 deaths were recorded, with 31 occurring in car seats, 5 in slings, 4 each in swings and bouncers, and 3 in buggies.

These findings mirror an older study published in the British Medical Journal back in 2006.

That report warned parents against keeping babies in car seats unchecked, particularly when not travelling, following the deaths of 9 children. But of these, 8 children died while sleeping in a car seat at home and only one baby died while in a seat as the car was being driven.

Both reports have warned parents against using car seats, travel systems and any kind of sitting device as a general place for your baby to sleep.

The Lullaby Trust is aiming to release new guidelines for parents on how to use car seats. However, you can follow these car seat and safe sleep tips from the Trust and Dr Erich K Batra who led the recent research:

Car seats

  • Car seats should not be used as sleeping areas outside of the vehicle
  • Do not leave children unsupervised (awake or asleep)
  • Never leave children in a car seat with unbuckled or partially buckled straps
  • Car seats should never be placed on a soft or unstable surface

Bouncers and swings

  • Infants in bouncers, strollers, and swings may be able to move themselves into positions that could restrict their airways
  • Restraints should be used according to manufacturer’s instructions but these may not prevent infants from getting into hazardous situations
  • Ensure that infants cannot twist their heads into soft bedding or slump forward in a seat
  • Do not place more than one infant together in a swing meant for one infant


  • If slings are not used correctly or safely there's a risk of your baby's airway becoming compromised
  • Your baby's face should be “visible and kissable” at all times
  • Always follow the 'TICKS' safety advice shown below when using a sling

General sleeping

  • Always place babies on their backs to sleep
  • Place your baby to sleep in a separate cot or Moses basket in the same room as you for the first 6 months
  • Use a firm, flat, waterproof mattress in good condition
  • Remove all pillows, soft bedding, cot bumpers and soft toys from the cot
  • Don’t let your baby get too hot
  • Don’t cover your baby’s face or head while sleeping or use loose bedding

We've got more on safety here…



Hazelann WilliamsFormer Reviews Editor

Having been a journalist for 15 years – and Reviews Editor at MadeForMums for five of those – Hazelann has accrued a lot of experience testing and reviewing every baby product imaginable.