New York: Infants and new born kids, if seated in cars for more than 30 minutes, may be at a risk of suffocation, suggests a study published in the Daily Mail.

According to the study, very young babies whose neck muscles are not strong enough to stop their heads flopping forward could stop breathing. This increases the risk they will be unable to breathe -- with potentially fatal results.

"There should be separate advice for very young babies. If you can avoid a journey, it's probably better to do so, restricted to no more than half an hour or so. But try to avoid unnecessary car journeys with young babies," said Peter Fleming, Paediatrician at the Bristol University.

Research carried out by the researchers used a laboratory in a laboratory to replicate the effects of sleeping in a car seat during a car journey at 30mph.

After half an hour in the seat, the amounts of oxygen in the blood of babies under two months old were found to have dropped 'significantly' while their heart rates increased.

The authors said their findings still mean babies should travel in a properly secured child seat during car journeys -- as is required by law. But they advise that an adult should sit next to the baby to make sure the infant is breathing properly.

"There have been reports of deaths of infants who have been left in a sitting position, including in car seats -- both on journeys, and when parents have used it as an alternative to a pushchair or cot for the infant to sleep in," Fleming added.

Car seat makers should provide consistent information to parents to warn them of the dangers of long car journeys with very young babies, the study suggests.