Craniosynostosis is a birth defect in which one or more of the sutures, or joints, between the bones in a baby's skull close prematurely. This can cause problems with the growth of the baby's brain and skull.
Symptoms of craniosynostosis vary depending on how severe it is. Some babies may have a head that is too small for their age, an abnormal shape to their head, or increased pressure within the brain. Often, however, there are no apparent symptoms. Craniosynostosis is diagnosed by looking at X-rays of your baby's skull.