Excessively large fontanelles are larger than expected soft spots for the age of a baby. In an infant, the spaces where the bones of the skull come together, but are not completely joined, are called soft spots or fontanelle (fontanel or fonticulus).
Fontanelles allows for growth of the skull during an infant's first year. Slow or incomplete closure of the skull bones is most often the cause of a wide fontanelle.
For general information, see fontanelles.
Larger than normal fontanelles are most commonly caused by:
Rarer causes:
If you think that the fontanelles on your baby's head are excessively large, talk to your health care provider. Most of the time, this sign will have been seen during the baby's first medical exam.
The health care provider will perform a physical exam and ask questions about the patient's medical history, including:
Note: An excessively large fontanelle is usually discovered by the health care provider, and the parents may not have been aware of its presence.
The health care provider may check the size of the fontanelles and the head over several months. This can help determine problems of the fontanelle and head growth.
Diagnostic tests may include:
Soft spot - large