The growth of the head circumference takes for the most part place during the first two years of life.
Congenital and neonatal problems are usually reflected on the growth of the head circumference during the first year, when the follow-up is thus especially important.
The size of a child's head should increase in parallel with the length of the child.
A child with an abnormal head size should be referred to a paediatric outpatient clinic for further investigations in the following situations:
acceleration of head growth > 1 SD as compared with the growth in length / acceleration of length growth
slowing down of head growth > 1 SD as compared with the growth in length / slowing down of length growth.
head growth deviates > 2 SD from the length growth, even if a clear acceleration or slowing down of head growth, as describe above, would not be observable AND
there are abnormal features in the child's appearance or
there is delayed or abnormal development
head growth is > +3 SD (macrocephaly)
head growth is < -3 SD (microcephaly).
Acceleration of head growth
Acceleration of head growth may be caused by an obstruction to the circulation of the cerebrospinal fluid (tumour, aqueduct occlusion/stenosis) or an interruption to its reabsorption (subdural bleed/effusion; consider trauma and abuse). Neurometabolic illnesses may also cause acceleration of head growth.
If, in addition to accelerated head growth, the child has a squint, an urgent referral for further investigations should be made without delay.
If the child is lethargic, has difficulty feeding or is vomiting, or if the anterior fontanelle is bulging and distended, or if he/she has lid retraction with impaired upgaze (”sunsetting”), he/she must be referred as an emergency case to the paediatric emergency department for investigations and treatment.
Slowing down of head growth
Slowing down of head growth may be due to premature ossification of cranial sutures or some neurometabolic disease or syndrome.
Head shape deformity
The growth of the head is determined by the growth of the brain.
There are different types of anomalies in the cranial shape of infants. These are in most cases mild and do not require treatment.
These self-correcting deformities include different depressions in the skull as a consequence of, e.g., the position of the foetus in the uterus or of the mode of delivery.
Deformational posterior plagiocephaly denotes unilateral flat area at the back of the head, which is caused by moulding of the head, rarely by an actual synostosis.
Premature fusion of the cranial sutures, i.e. craniosynostosis, causes anomalous cranial shapes.
Different types of ridges (e.g. a ridge formed by the metopic frontal suture) or eminences in the cranial bones do not require surgical treatment.
A progressive deformity of the cranial shape associated with craniosynostosis of the coronal, sagittal or lambdoid sutures warrants consultation with a plastic surgeon.