Well, anytime an infant's head is larger than normal, one needs to find out why.
Is it a "backup" of the cerebrospinal fluid in the brain that is causing it to enlarge from it's inability to drain (called hydrocephalus)?
Or could it be a tumor causing fluid to back up?
Or could it be blood or fluid on the outside of the brain (subdural hematoma or hygroma)?
Or it could simply be that your child has a larger head genetically.
The reason that your doctor wants to find out now, is if it is a correctable condition (hydrocephalus), treating it now will prevent possible developmental delay.
Please click "ACCEPT" if I answered your question to your satisfaction. A BONUS is appreciated.
If you have other questions, please ask them.
M.D. - Neurological Surgery