Parents should not be surprised if the next time they visit their pediatrician they are told to keep their child in a rear-facing car seat until they reach the highest weight or height allowed by the seat manufacturer. This change in advice has been spurred by recent analysis of the protection car seats provided during actual crashes. This analysis showed that "children under the age of 2 are 75% less likely to die or sustain serious injuries when they are in a rear-facing seat." The data revealed that children ages 12-23 months were 5 times less likely to be injured, regardless of the type of crash, if they were in a rear-facing car seat.
Children in forward-facing car seats are at a much higher risk of injury to their head and spines because their heads are disproportionately large for their bodies. Rear-facing seats better distribute the force of a crash and children are therefore less likely to be severely injured as a result. A recent commentary in the journal Pediatrics encouraged pediatricians to convey this information to their patients and to dispel the myth that if a child's feet touch the back seat then they should be put in a forward-facing seat. According to the commentary, "lower-extremity injuries are rare for children facing the rear, on the order of 1 per 1000 children. In addition, riding facing front does not eliminate a child's risk of lower-extremity injuries, because these injuries, as well as injuries to the head and spine, have been described among forward-facing children in [car seats]." As the author pointed out in an article published in the AAP News, having to treat a leg fracture after a car crash is far better than having to treat paralysis.
You may find your pediatrician weary of giving you an end age or weight as to when you can safely turn your child forward-facing, this may be because studies done in Sweden recommend children to remain rear-facing until 4 years of age. For this reason, European car seats are manufactured differently to allow larger children to remain rear-facing. In the US, most convertible car seats can accommodate children in the rear-facing position until around 35 pounds, which should allow over 95% of children to remain rear-facing until their second birthday.
Parents should check their car seat manual for the weight and height limits of their child's car seat should discuss any concerns they have with their pediatrician or a certified child passenger safety technician in their area.