Infant head circumference development standard comparison table shows: three-month-old baby’s healthy head circumference in 38.2 ~ 43.4 centimeters, so three-month-old baby’s head circumference 42 is within the normal range.
The size of an infant’s head circumference can reflect the degree of development of the brain and skull to a certain extent. Clinically, too small a head circumference is commonly seen in cerebral hypoplasia and microcephaly, which is often accompanied by mental retardation, epileptic seizures, and uncoordinated limb movements, and other phenomena. Hydrocephalus is the most common cause of large head circumference.
Parents should always keep an eye on their babies’ head circumference and measure it correctly. If an abnormality is detected, it is first necessary to exclude hereditary physiological factors, in which case the oversize or undersize of the infant’s head circumference will not have a negative effect and does not require medical attention. If it is a pathologic factor, we must consult a doctor in time, and treat it as soon as possible after a clear diagnosis.
In summary, three months baby head circumference of 42 centimeters is normal, if there is any discomfort, you should consult a doctor in time.