Infant car seats are not designed to be used as cribs, or for extended amounts of time. The risk of baby's head falling forward in a way that would affect breathing is also one reason why it's important to be sure that rear-facing car seats are installed at the proper angle, according to manufacturer's instructions. Robinson suggests that parents limit infants to a couple of hours of sleep in a car seat at a time, and never overnight. Even during road trips, it's a good idea to take baby out of the car seat every couple of hours, he said. The Canadian Pediatric Society recommends that babies not be allowed to sleep longer than one hour during car rides.
It's important to note, though, that the risk of asphyxiation in a car seat is much lower than the risk of being injured or killed in a vehicle crash if a baby is not properly restrained in a car seat. All experts, including the coroner who released this report, agree that babies and toddlers should be properly restrained in a car seat when they are riding in a vehicle.