In a study of car crash data from 16 US states, researchers found that children younger than three years old were 43 percent less likely to be injured when their seat was fastened in the centre of the back seat rather than one of the side seats.
Experts already recommend that parents position car seats in the centre of the rear seat, and the current findings bolster that advice, according to Michael J. Kallan and colleagues at the University of Pennsylvania and Children's Hospital of Philadelphia.
Unfortunately, only 28 percent of children in their study were sitting in that position at the time of the car accident, the researchers report in the journal Pediatrics.
There are obstacles to placing a car seat in the centre position, Kallan's team acknowledges.
It is physically harder to strap a child, especially a heavier child, into a centre-positioned seat. A centred child seat can also make it difficult for other people to sit in the rear of the car.
But based on the current findings, the researchers write, this centre position is the safest place for babies and toddlers to ride.
The results are based on data from 4 790 car crashes involving children ages three and younger that occurred between 1998 and 2006. At the time of the accident, 41 percent of the children were in a car seat positioned in the right-hand back seat, while 31 percent were in the left-hand seat.
The centre position was the least popular, but the safest. The reason, in part, was that children in a centred seat were better protected during a side-impact crash, according to Kallan's team.
"Recommendations should continue to encourage families to install child-restraint systems in the centre of the rear seat," the researchers conclude.
They note that there are several online resources for parents who need information on installing child safety seats. The Children's Hospital of Philadelphia maintains such a site, at www.chop.edu/carseat.
Parents can also go to a local child safety seat inspection station, where inspectors will give them advice on properly using the seats. The National Highway Traffic Safety Administration maintains a searchable database of inspection stations, at www.nhtsa.dot.gov/cps/cpsfitting.