You must have heard or seen Flat Head Syndrome.
It occurs when a baby's head develops a flat spot due to pressure on that area. Babies are vulnerable because their skull is soft and pliable when they're born.
Known as Positional plagiocephaly in medical terms, Flat head typically develops after birth when babies spend time in a position that puts pressure on one part of the skull. Because babies spend so much time lying on their back, they may develop a flat area where their head presses against the mattress.
Besides changing position of baby frequently while sleep and while beast feeding, using a soft grain filled pillow, using physical therapy or putting on baby helmet, there is one thing that most people fail to try – the Tummy Time. Tummy time is when you put your baby on his/her tummy for some amount of time during the waking hours.
During waking hours, tummy time is helpful for the development of motor skills. It also helps preventing flat head by strengthening babies' neck muscles. Stronger neck muscles enable babies to move their head around while sleeping so it doesn't always rest in the same position. So even if you fail to change the position, the baby naturally will.
Put the baby on her tummy when she's not asleep starting in the first few weeks of life. Slowly they will develop the strength.
But remember that everyone's skull is a bit asymmetrical, which might get rounded by itself by 6months of age. Nevertheless, if you notice flattening of your baby's head at any time, don't wait – talk to the doctor about it right away.