What causes Flat Head Syndrome in new-borns?

Mis-shaped heads in new-borns (babies of less than a week old) is probably caused by either craniosynostosis (where skull bones fuse prematurely) or from pressure in the uterus or from the birth process itself.

It is relatively rare for babies to have Flat Head Syndrome until they have been placed on their back on a flat mattress thereby flattening the skull bones.