Buyer's guide to infant car seats

What's available
When buying a chair for your baby at any age you need to be sure to get the right size, and the simplest way to do this is to buy by weight. Weight spans can vary from chair to chair, but broadly they are grouped as: 'Group 0' (0-10kg) and '0+' (0-13kg) - both from birth to around 9-12 and 12-15 months respectively; Group 1 (9-18kg, or from around 9 months to up to 4 years); Group 2 (15 - 25kg) and Group 3 (22 - 36kg). For newborns you'll need a seat that is rear-facing because these have a more reclined position, giving your baby's back and neck essential support. You have the choice of Groups 0 and 0+, together known as infant carriers, a combination chair that spans both Group 0 and Group 1, or a carry cot.

Infant carriers
Infant carriers are designed to be relatively easily fitted and removed from the car and, as the name suggests, should be fitted with handles so you can transport your baby with minimum disturbance. With a Group 0+, 0-13kg, chair you'll be able to leave your baby facing backwards for longer, which is preferable and most infant carriers on the market are, in fact, Group 0+.

Britax First Class combination car seat: £119

Combination chairs can both face rearwards for newborns and then face forwards for older babies. On the plus side this means that you only have to buy one chair for your baby, but on the minus side combination seats are heavier and clunkier than infant carriers and aren't designed to carry around your baby in, so you'll have to take your baby out of the seat every time you want to take her out of the car. Although on the face of it a combination seat is more economical than buying two seats, if you're planning on more than one baby it will make more sense to get two separate seats designed specifically for each purpose, as when the second baby comes along you'll need a second chair anyway.

Carrycots
Carrycots lie sideways across the back seat of the car, strapped in by two seat belts. As the name suggests, carrycots are highly portable and the fully flat position means they can be used for longer periods. However, there is a safety question mark over the use of carry cots in the car, as independent tests have shown that they aren't as safe as a car seat in collisions.

Another disadvantage with carry cots is the amount of space they take up: depending on the size of your car you probably won't have much of the back seat left. A further problem is that once your baby can sit up unaided (at around 6 months) the carrycot will no longer be suitable, so you'll need a car seat then anyway.

What to look for
Safety
Whatever seat you buy should conform to European safety standards, this can be an issue with buying second-hand car seats, or importing seats from countries like the USA. If you are buying a seat second-hand then make sure you know its history - it may have been damaged in some way that's not immediately obvious. Look for a seat that offers good side protection and is of solid construction with quality materials.

If you want to use a rear-facing seat in the front seat of the car make absolutely sure that it's safe to do so. If there's an airbag in the front seat then it's not safe.

Unless your infant carrier is adjustable to a fully-flat carry cot position then it's not suitable to leave your young baby in for prolonged periods: A fully flat position offers your baby's spine the best support for development. with most infant carriers it's not recommended that you leave your young baby in the seat for more than a couple of hours at a time.

Fit
Whatever kind of seat you go for, if you're opting for fitting with a three-point seat belt, check that the model of seat you're considering fits easily into your car in all the seats you plan to be able to use it in as some seats will fit better than others and some may not fit at all, because of differences in seat upholstering and seat belt lengths. You should be able to try out seats in your own car with the help of a shop assistant at any reputable shop. For a good fit you should have no difficulty in fitting the car seat and, when secured with the seat belt, the seat should be held fast with little movement.

A new standard in child seats, ISOFIX, enables you to fit the child's seat directly into ISOFIX points in the car's own seat, rather than using the seatbelt to secure it and so side-stepping the issue of whether a seat will fit - if your car is ISOFIX ready then any ISOFOX seat will fit. More car manufacturers are adopting this standard all the time and if you have a relatively new car then you may well already be geared up for an ISOFIX seat, so it's worth checking (ask your dealer or manufacturer). As well as being more convenient to use, in testing ISOFIX seats are also safer because there's less chance of the seat being incorrectly fitted. Child seat manufacturers are bringing out more and more ISOFIX fitted seats, and even if you don't yet have ISOFIX in your car, if you're thinking about getting a new car in the next couple of years it makes sense to consider a seat that is ISOFIX ready as well as fitting with a seatbelt.

Maxi-Cosi Cabrio infant carrier as part of travel system: £89

Comfort
For very young babies the seat should have a 'head hugger' to give full support to your baby's neck until he's old enough to hold his own neck up comfortably. Check the other padding on the seat for comfort.

Portability
Infant carriers should have handles so that you can lift the baby in and out of the car when still in his chair, perfect for when he's fallen asleep and you don't want to wake him. If you have a travel system you'll also be able to attach the car seat onto the pushchair frame for even greater flexibility.

Accessories
Sun and wind shades for infant carriers are fairly standard, particularly in models that are part of a travel system. Seats may also include storage compartments at the back, if that's something you find useful.