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30 Jun 2021

What is a lie-flat baby car seat and do you need one?

We explain why you might want a child car seat that reclines to a flat or nearly-flat position
Baby sitting in Maxi Cosi Marble car seat

Car journeys with little ones can be taxing at the best of times, so knowing they're safe and comfortable can provide some much needed peace of mind before you set off.

When transporting babies, particularly very young infants, a lie-flat position is beneficial because it enables them to breathe more easily as they won't slump forward in their seat.

It also puts less pressure on their spine and hips compared with a more upright position.

It's why you may spot car seats and pushchairs with options to recline backrests to a flat or nearly flat position.

Read on to find out about the baby car seats we've tested which have a lie-flat or nearly flat recline option.

Pick a Best Buy car seat that's safe and comfortable

Maxi-Cosi Marble, £200

This rearward-facing i-Size infant carrier is approved for use with babies from 45cm to 85cm tall, which is from birth to about 15 months old. It can only be installed using the dedicated Marble Isofix base in approved cars.

The seat reclines to allow babies up to 75cm (around 12 months) to sleep in a nearly flat position, both when travelling in the car and when attached to a compatible pushchair frame.

It also comes with an extra-large sun canopy to help keep baby hidden from sun rays.

We've recently tested it, so read our full Maxi-Cosi Marble car seat review to find out how it scored during our tough tests, which include a side-impact collision that mimics two cars crashing into each other at 30mph.

Cybex Cloud Z + Base Z, £410

Cybex Cloud Z car seat

When used with Cybex Base Z, the Cybex Cloud Z i-Size has a 180-degree swivel to help take some of the strain out of putting your baby in the seat and taking them out.

It's approved for use for babies from 45cm to 87cm tall, which is from birth up to about 18 months old.

The seat can be changed to a lie-flat position, but only when used as part of a pushchair travel system outside of the car.

Read our Cybex Cloud Z i-Size + Base Z review to see the crash test results for this car seat.

Maxi-Cosi Jade, £428

Maxi Cosi Jade car seat

Launched in 2019, the Jade was the first i-Size approved carrycot-style car seat.

You click it into a base just like an infant carrier, but your newborn can lie flat. This solves the issue of not being able to transport very young babies in car seats for long periods of time.

It can be used from birth until your baby measures 70cm, which isn't long and could be as young as six months old, so you'll need to weigh up the cost versus how much use you'll get out of it.

Read the full review of the Maxi-Cosi Jade + 3wayFix base to find out if the short shelf life is worth it thanks to good crash test results.

Joie i-Level, £200

Joie i-Level baby car seat

The Joie i-Level is, as the name suggests, an i-Size car seat. It's installed in your car via an Isofix base and is suitable from birth until your child reaches 85cm, but less than 13kg, which is approximately 12 to 15 months old.

It has a lie-flat recline option, which you can use in the car or as part of a travel system with Joie pushchairs.

The i-Level comes with a zip-open expandable canopy and a plush infant insert to ensure a cosy fit for your baby.

Read our full review of the Joie i-Level to find out if it's safe and easy to install.

Britax Ru00f6mer Britax Baby-Safe2 i-Size, £338

Britax-Römer-Britax-Baby-Safe2-i-Size car seat

The Britax Ru00f6mer Baby-Safe2 is an i-Size-approved baby car seat that's suitable from birth up to 83cm, which is around 15 months old.

It has a back rest that automatically flattens for younger babies, and adaptors integrated into the base for use on a travel system.

The hood is detachable, and it has a comfy insert for small babies as well as a five-point harness to secure them in the seat. The harness has a one-pull adjuster strap, which makes it easier to fit around your baby.

Find out how this car seat scored in our tough crash tests by reading the full Britax Ru00f6mer Baby-Safe2 car seat review.

How long can your baby stay in a car seat?

If a lie-flat car seat isn't for you, a standard model will be safe and should protect your baby in a crash. However, it's important to keep an eye on how long your baby is kept in their car seat.

If your baby is less than a few months old, try not to let them spend longer than 20 or 30 minutes in the seat without a break - this time includes if you go from transporting from your car to clicking the same seat on to a pushchair travel system.

Once your baby is older than six months old, this can be extended to two hours.

But don't keep your baby in their car seat for longer than two hours at a time and try to have regular 10 or 15-minute breaks if you're going on a long road trip.

A car seat should not be used as a place for your child to sleep for long periods of time, and as hard as it may seem to disturb your peaceful little, you should remove your baby from the seat once you get home and place them on a flat surface.

How we test baby and child car seats - find out more about what's involved.