There's a pillow out there designed specifically to prevent flat head syndrome in babies. Flat head syndrome, also known as positional plagiocephaly, is a condition in which a baby's head becomes flattened on one side. This can be caused by a baby spending too much time lying on their back, and it can lead to developmental problems down the road. Flat head prevention pillows are designed to help babies maintain a round head shape by providing support and cushioning. They typically have a divot or indentation in the center of the pillow, which helps to keep the baby's head in a neutral position.