• you think that the fontanelles on your baby's head are excessively large. Quite often this sign will have been detected at the first newborn examination in the hospital.

The medical history will be obtained and a physical examination performed.

Medical history questions documenting the symptom in detail may include:

• time pattern
  • When did you first notice that the fontanelle looked large?
• location
  • Which "soft spots" are affected?
• quality
  • Is it always the same, or does it change in any way?
• other
  • What other symptoms are also present?
  • Have large fontanelles been present with previous babies?

Note: This finding is usually discovered by the health care provider, and the parents may not have been aware of its presence.

The physical examination may include repeated assessment of the size of the fontanelles and the head circumference over several months. This can help determine abnormalities of the fontanelle and head growth. Transillumination of the skull using a bright light may be done to help determine the presence of hydrocephalus, "water on the brain," a relatively common cause of an enlarged fontanelle. Transillumination can also help discern separated sutures.

Diagnostic tests that may be performed are:

• head circumference measurements
• transillumination of the skull (generally in the newborn or infant of only a few weeks)
• ultrasound of the head
• head X-rays , CT scan, or MRI
• specific tests for suspected causes, such as a serum thyroxin (T3 and T4) for suspected hypothyroidism

AFTER SEEING YOUR HEALTH CARE PROVIDER
If a diagnosis was made by your health care provider as to the cause of the large fontanelles, you may want to note that diagnosis in your child's personal medical record. You may also want to document your own findings of the child's head circumference as he or she grows.