n. a swelling on the head caused by a collection of bloody fluid between one or more of the skull bones (usually the parietal bone) and its covering membrane (periosteum). It is most commonly seen in newborn infants delivered with the aid of forceps or vacuum extraction or subjected to pressures during passage through the birth canal. No treatment is necessary and the swelling disappears in a few months. If it is extensive, the blood in the fluid may break down, releasing bilirubin into the bloodstream and causing jaundice. A cephalhaematoma in an older baby or child is evidence of some recent injury to the head; occasionally an unsuspected fracture is revealed on X-ray. See also chignon, subaponeurotic haemorrhage.
Subjects: Medicine and Health.