MONTREAL - Allowing infants to sleep in car seats can lead to serious breathing problems and should be discouraged, a Quebec coroner said Wednesday, a year after a two-month-old boy died after his mother placed him in the seated position in an effort to prevent colic.

The youngster was laid to rest in a car seat inside his crib after feeding last Feb. 23 and was found unconscious, pale and glassy-eyed about three hours later.

Efforts by the parents to revive the infant were fruitless and he was declared dead in hospital.

A coroner's report released Wednesday has linked the death to "positional asphyxiation."

Coroner Jacques Robinson said it's common for a baby's head to slump forward while in a car seat and that can diminish a baby's ability to take in oxygen.

"The car seat is for the car," he said. "It's not for a bed or sleeping."

Robinson added, however, he has nothing against car seats when they are properly used.

Robinson encourages parents to put their babies to sleep on their backs on a firm surface and to avoid placing obstacles like toys, dolls or blankets around them.

He's also calling on Quebec health and social services to ensure members know about the danger of car seats and sleeping babies and that they relay that information to parents during post-natal visits.

The Canadian Pediatric Society also discourages parents from using car seats during nap time and Quebec public health officials also recommend frequent stops during travel as infants should never spend more than an hour in a seat at a time.