New babies do not have enough strength in their necks to hold their heads up. Their heads tend to flop sideways—this is OKAY! But when the car seat is too upright, their heads tend to flop forward, and this is NOT OKAY. A baby’s head should not fall forward in the car seat, so that his chin touches his chest. This is dangerous and can interfere with the baby’s breathing.
Two tips to make sure your newborn’s head stays in a safe position.
Make the harness straps snug. Snug straps do more than just keep a baby safe in a crash. They prevent babies from slumping over, giving them the support they need to keep their bodies and heads straight.
Recline the car seat properly. For safety and comfort, a newborn should ride semi-reclined, so that the angle of the car seat (where their head and chest rest) is reclined enough to keep the baby’s head back and his chin off his chest, but never more than 45 degrees from vertical. Most newborns will require a 45 degree angle to keep their heads well positioned and their airways open. We must position the newborn’s head and neck for him, since he doesn’t have the neck muscles to do it himself. Without this reclined position, a child’s head could easily fall onto his chest, pinching off his airway. As he grows older and can hold up his own head, you can move the car seat into a more upright position to provide better crash protection.
Here’s a comprehensive video showing how to buckle in your newborn.
We know parents of newborns don’t have too much time to watch videos–so if you just want to learn how to make the straps snug, fast forward to 03:55.