Fontanelles: "Holes" in the Baby's Head

Fontanelles are frightening to parents. However, these holes are absolutely normal and necessary for your child. What are fontanelles and how can you take care of them?

Reviewed and approved by the doctor Nelton Ramos.

Written by Macarena Esperanza Marina

Last update: 27 December, 2022

Fontanelles are one of the most feared parts of motherhood. It is no wonder that these myths regarding newborns’ anatomy concern us. The truth is that fontanelles are absolutely normal and necessary for your child’s development.

Fontanelles are that soft part of your baby’s head and are where the bones of the skull meet. They become separated at birth and will remain open for several months to allow brain growth.

Your child will not only have one opening but six, through which you will feel their heartbeat. But do not be scared, because at 18 months those curious “holes” in your child’s head will close.

Continue reading to find out what fontanelles are and how to care for them.

What are fontanelles?

When your child is born, their skull is not formed by a single bone, but by a set of bones that unite and fuse over time. Thus, they allow the baby’s head to grow enough during the first year of life.

The fontanelle is the area of the baby’s head where the bones of the skull have not yet come together, which allows rapid stretching and compression of the skull and expansion of the brain.

This “incompleteness” at the cranial level allows the bones to move during birth and even overlap on top of each other so that the baby’s head can descend through the narrow vaginal canal.

What happens if I touch my child’s fontanelle?

This is one of the most common concerns. However, there is nothing to fear. The membrane that covers the fontanelles is resistant due to its extreme hardness. It is difficult to penetrate.

Do not forget that during childbirth, the fontanelle is already open, which doesn’t imply any malice or the fracture of any bone in the child’s head.

Just remember to be delicate with every movement you make with your child, because they are sensitive.

In fact, at every pediatric appointment, the doctor will examine, measure and palpate these holes to monitor their size and make sure that growth is normal.

This is the only way to prevent or diagnose possible anomalies in the child’s brain development.

When doe the fontanelles close?

The most notorious fontanelle for the parents is the one located in the upper frontal part of the skull. It is estimated that it closes between 7 and 19 months of age.

But, as we said previously, this is not the only space the child has in his head. The hole in the back of the skull is usually closed between the first and third months of age.

On the sides, there are also spaces at the temple height and behind the ear towards the base of the skull. While the first ones close around 6 months after birth, those behind the ear do so between 6 and 18 months after the baby is born.

Are the fontanelles normal or should I consult the pediatrician?

The fontanelles should feel firm and slightly concave to the touch. When the baby cries, is lying down or vomiting, the fontanelles could be momentarily swollen.

But when the child calms down and keeps their head upright, they should normalize.

These spaces can be tense or protruding when liquids accumulate in the cranial cavity or when there is an increase in cerebral pressure, as in cases of hydrocephalus.

However, if the fontanelle normalizes when the baby calms down and raises his head, you should not be alarmed.

Now, in case you notice that your child has a really bulging fontanelle, and even more so if this condition is accompanied by a feverish state or lethargy, take them immediately to the pediatrician due to a medical emergency.

If your finger gently caresses your small child’s head and you feel that it is sunken, you should also contact your pediatrician as soon as possible because it may be a sign that the baby is dehydrated.

Problems with fontanelles

Sometimes the fontanelles close prematurely and, if this closure is complete, a condition known as craniosynostosis is suspected, where the baby’s head also has an abnormal shape.

Likewise, if there is a narrowing of the cranial cavity that could generate a space conflict, it can also be related to an anomaly of the baby’s fontanelles.

In both cases, depending on the degree of closure of these holes and how many are involved, the doctor can opt for surgery to allow the brain to continue growing.

For this reason, it is not necessary to worry, but rather, to be attentive to the state of your little treasure’s fontanelles.