Plagiocephaly and brachycephaly (flat head syndrome)
Overview
Babies sometimes develop a flattened head when they're a few months old, usually as a result of them spending a lot of time lying on their back.
Causes
The skull is made up of plates of bone that strengthen and join together as a child gets older. A young baby's skull is still relatively soft and can change shape if there's constant pressure on a particular part of their head. Reasons why this may happen include: sleeping on their back – the back or side of a baby's head can become flattened as a result of always sleeping on their back, but it's important they do this to reduce the risk ofsudden infant death syndrome (SIDS)problems in the womb – pressure can be placed on a baby's head before they're born if they're a bit squashed in the womb or there's a lack of amniotic fluid to cushion thembeing born prematurely – premature babies are more likely to develop a flattened head because their skull is softer when they're born, and they may prefer to rest their head on one side at first as they're not yet able to move their head themselvesneck muscle tightness – this can prevent a baby turning their head a particular way, meaning one side of their head is placed under more pressure Occasionally, a flattened head can be caused by the plates of the skull joining together too early. This is known ascraniosynostosis.