Q&A: What is a fontanel?

The fontanel (also spelled fontanelle) is a "soft" spot on the head. There are two fontanels on a newborns head. These soft spots, which are covered by fibrous tissue, actually allow for growth and for movement of the bony plates that make up the skull. During a vaginal delivery, the ability to have give and flex to the head is a good thing!
There is an anterior and a posterior fontanel. The posterior fontanel is much smaller and triangular and is located on the lower part of the back or the head. This fontanel will close around 6 to 8 weeks of age. The anterior fontanel (the one on the top of the baby's head) is diamond shaped and will close around 18 months of age. There are two smaller fontanels at the sides of the baby's head above the jaw and behind the ear. The anterior and posterior fontanels are much more prominent.

Your pediatrician and the hospital nurses will assess the fontanel to make sure your baby is normal and healthy. A "normal" fontanel will not be sunken or bulging. A bulging fontanel could mean increased pressure in the brain and a sunken fontanel may be a sign of dehydration. Ask your nurse or pediatrician if you have any questions or concerns about your child's skull development.