This is possible if left in a car seat for too long. Newborns don’t have strong enough neck muscles. As such their head can flop forward placing their chin on their chest. In doing so the trachea is slightly restricted so after a long period a baby can start to suffocate. This research has persuaded doctors to advise parents to limit newborns in car seats for 20mins until they can lift their heads. Once they reach two months they can move their head and the risks drop considerably.