Health Encyclopedia

Fontanelles - excessively large

Definition

Excessively large fontanelles are larger-than-expected soft spots for the age of a baby. In an infant, the spaces where bones of the skull come together, but are not completely joined, are called soft spots or fontanelle (fontanel or fonticulus).

Alternative Names

Soft spot - large

Considerations

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.

Common Causes

Larger-than-normal fontanelles are most commonly caused by:

Achondroplasia
Down syndrome
Hydrocephalus
Intrauterine growth retardation (IUGR)
Prematurity

Rarer causes:

Apert syndrome
Cleidocranial dysostosis
Congenital rubella
Neonatal hypothyroidism
Osteogenesis imperfecta
Rickets

Call your health care provider if

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.

What to expect at your health care provider's office

The health care provider will perform a physical exam and ask questions about the patient's medical history, including:

When did you first notice that the fontanelle looked large?
Which soft spots are affected?
Is it always the same, or does it change in any way?
What other symptoms does your child have?
Have you had other babies with large fontanelles?

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:

Blood tests for suspected hypothyroidism
Head circumference measurements
Imaging tests of the head, including x-rays, CT scan, or MRI
Transillumination of the skull (generally in the newborn or infant of only a few weeks)
Ultrasound of the head

Review Date:11/14/2007
Reviewed By:Deirdre O’Reilly, M.D., M.P.H., Neonatologist, Division of Newborn Medicine, Children’s Hospital Boston and Instructor in Pediatrics, Harvard Medical School, Boston, Massachusetts.

ADAM Quality A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.