Facts

• All babies have the size of their head measured at birth and at their routine medical checks during vaccination visits.

• These measurements should be plotted on a growth chart.

• A rapidly increasing head circumference may be caused by a serious illness, including a brain tumour. It is important to note that all babies' heads will grow, usually in line with their height and weight.

• Any baby or young child under the age of two who has an increasing head circumference which is out of the normal range compared to their height and weight requires an assessment to determine the cause. Their head circumference should be measured and plotted on a growth chart and compared to previous measurements.