Hello. Has anyone tried using a special mattress, pillow or other method to prevent/reshape flat heads? My 3 yr old DS has a really flat head and so want to avoid this problem with my baby DD. Although at 6 months it may already be too late! Despite carrying her in a sling nearly all day and buying a baby hammock its still gone flat (probably from the time she spent napping on our bed or in the car seat!) Both my kids sleep flat out on their backs and there is no sign of my DS's head 'filling out'. Any advice much appreciated.