New research suggests most UK parents are too quick to switch their children to front-facing car seats.
In an article in the British Medical Journal, a team of doctors say mounting evidence suggests it is safer for children to use a rear-facing seat until the age of four, and wants parents to be advised accordingly.
In the UK it is common practice to switch babies to a front-facing seat when they weigh 9kg (20lb) - around the age of eight months for an average boy.
However, the doctors also stess that this does not mean forward-facing seats are dangerous.
Dr Elizabeth Watson and Dr Michael Monteiro cite evidence from Sweden, where using a rear-facing seat up to the age of four is common practice.
There, studies have shown that children who died in accidents restrained in a forward-facing booster seat could potentially have survived if they had been travelling in rear-facing seats.
Another study used the US National Highway Traffic Safety Administration database to examine crashes involving 870 children between 1998 and 2003.
It concluded that rear-facing seats were more effective than forward-facing seats in protecting children aged 0-23 months for all crash types.
Recent crash tests have also reported that rear-facing seats resulted in significantly lower neck and chest injury measures compared with forward-facing seats.
Dr Watson said: "Rear facing car seats cradle a child in an impact with any frontal component, and align the head, neck and spine, spreading the crash forces over all of these body areas.