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Best baby car seats

Baby vs child car seats: what's the difference?

By Alison Potter

Article 1 of 2

Babies need specific protection in a baby car seat. Find out what to look for to help keep your little one safe when travelling

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Baby car seats are, as the name suggests, specifically suitable for newborns and younger babies. 

Child car seats are designed to protect children's soft bones and vulnerable internal organs at each stage of development, from birth to the age of 12 or when they reach 135cm tall. 

But babies need different levels of protection compared with toddlers and older children, so you need to make sure you're getting a car seat that is suitable specifically for newborns and younger babies. This will ensure that your baby will travel in the best position and be supported all the way.

To find out which seats we recommend, see our car seat reviews.

Keeping babies safe in car crashes

To reduce the risk of injuries to your baby in the event of a crash, a baby car seat needs to:

  • make sure your baby’s head doesn't move around, which causes the neck to stretch
  • stop the head banging into other surfaces, such as the front seat or car door
  • surround your baby with a protective shell to prevent them being hit by bits of car or debris
  • distribute the pressure from the child restraint as widely as possible over the strongest parts of the body: in an infant, the strongest part of the body is the back.

46%parents who incorrectly thought it was safest for babies to travel forward-facing (rather than rearwards) at nine months*

The best way to help keep your baby safe in a car crash is by keeping your child in a rear-facing baby car seat for as long as possible. 42% of 5,316 parents we surveyed in 2018 thought it was safest for babies to travel forward-facing (rather than rearwards) in a car seat, which is false.

In a frontal impact (one of the most common types of crash) a rear-facing seat pulls the child into it, cushioning the head and back and limiting the movement of the head on the neck.

 

Keep babies and younger children in a rear-facing baby car seat or child car seat for as long as possible.

 

We recommend that you leave your baby in a rear-facing child car seat until they are least 15 months old, or the first of these events occurs:

  • They reach the weight limit of that seat (13kg for Group 0+, 18kg for Group 1)
  • The crown of their head is level with the top of the car seat.

You don't have to move your baby forward-facing when he or she reaches 15 months of age, though. 

There's now a wider choice of car seats available that can be used rear-facing until your baby reaches 18kg/105cm, which is around four years old. And there are some seats that allow rear-facing use for much longer, meaning you can keep your child rear-facing for as long as you (and your child) likes – assuming the car seat fits your car, of course. 

Find out which baby car seats were the best on test – browse all our child car seat Best Buys

Check out the car seats we've given safety alerts to, and the reasons why, in our guide to Don't Buy child car seats.

Not a Which? member? Join Which? to access these and our thousands of other independent reviews and Best Buys.

Protecting babies in child car seats

When babies are born, their bones and muscles still have a lot of growing and strengthening to do. They're particularly vulnerable to injuries caused by impact and uncontrolled movements of their head.

The head, neck and spine

The head is large and heavy in comparison with the rest of a baby's body, accounting for about a quarter of its total length and about a third of the weight.

The neck muscles are weak and unable to lift or control the movement of the head.

Bones in the infant spinal column are held together quite loosely by weak ligaments. This makes it fairly elastic, allowing it to stretch up to 5cm. But the spinal cord will snap if it's stretched too much, which can be fatal.

Babies are particularly vulnerable to injuries caused by impact and uncontrolled movements of their heads.

The skull

The skull bones are separated by membrane-filled spaces that slowly grow together, but are not fully fused until 18-24 months after birth.

This means that a baby's skull is very flexible – relatively low impacts can result in significant deformation of the skull and brain. The smaller the child, the lower the impact needed for injury.

The chest and pelvis

A baby’s ribcage is very flexible, too. Impact to the chest can result in the chest wall squashing onto the heart and lungs.

The ribcage is not well developed and can't protect some of the abdominal organs.

The bones in the infant pelvis aren't fused together strongly like an adult's.

These things mean an infant's chest and pelvis can’t absorb strain from a restraint without the risk of injury to the internal organs, which is where a good baby car seat comes into play. A well-designed seat will cushion your baby in the event of a crash, and help to divert the crash force away from your baby's body.

Carrycot versus baby car seat

Our experts agree that the safest way to transport babies is in a rearward-facing infant carrier or baby car seat. A good baby car seat will help protect your baby in both frontal and side-impact crashes.

However, car-seat carrycots can be a good solution for newborn babies, especially premature babies or those with medical conditions who need to be transported lying flat.

In this instance we'd recommend a car-seat carrycot with good crash test results.

However, there are some drawbacks with using this type of car seat that you need to be aware of: 

  • A carrycot will take up a lot of space across the back seat, which may not be that practical if you have to transport multiple children. 
  • They can often be quite cumbersome to install.

Also, because they are suitable only for babies up to 10kg, parents may change to a forward-facing next stage seat too early.

It's considered safest to keep your baby in the lowest group car seat until they reach the weight limit, or outgrow it.

 

You should never use a pushchair carrycot in a car, unless it's also specifically approved for use as a child car seat.

We haven't found many carrycots and lie-flat child-car seats that protect children adequately in our crash tests. For this reason, we don't generally recommend them, but recently we have started seeing baby car seats with seating positions that hold your baby less 'upright'.

If a baby car seat does well in this area, this will be highlighted in each review.

If you already own a carrycot-style car seat and it doesn't have good crash test results, we suggest you buy an alternative Group 0+ or i-Size/R129 baby car seat to use in your car. 

Carrycot car-seat advice

If you are using a carrycot car seat, you should:

  • place it across the back seat, as close to the middle as you can. This may use up more space, but it means your baby is less vulnerable in a crash
  • place your baby’s head as far from the door as possible to try to avoid contact with the door in a crash.
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