A cephalohematoma is a traumatic subperiosteal hematoma which is bounded by the periosteum and cannot cross sutures. This distinguishes it from a subgaleal hematoma, which does cross sutures. Cephalohematomas occur in 1–2% of live births. The incidence increases after forceps extraction. Cephalohematomas usually gradually incorporate into the calvaria by ossification. Cephalohematomas may be unilateral or bilateral.