what is a fontanelle

A fontanelle, also known as a "soft spot," is a unique feature of a newborn babys skull. It is a space between the bones of the skull where bone formation is not complete, and it is covered by a membrane. There are several fontanelles on a newborns skull, located mainly at the top, back, and sides of the head. The fontanelles allow for growth of the brain and skull during an infants first year. The anterior fontanelle is the largest of the six fontanelles and is located at the junction of the coronal suture and sagittal suture. It is diamond-shaped and ranges in size from 0.6 cm to 3.6 cm with a mean of 2.1 cm. The fetal anterior fontanelle may be palpated until 18 months. The fontanelles should feel firm and slightly curved inward to the touch. If a fontanelle changes or feels different than usual, it may be a sign that the babys health needs to be checked. A tense or bulging fontanelle occurs when fluid builds up in the brain or the brain swells, causing increased pressure inside the skull.