The fontanelle in babies

From an early age, whenever a newborn is near, we are reminded to "be careful of the baby's fontanelle"! But as we grow up, do we really know what it is? Where is it located? And is there actually only one on a baby's head? And also, what should we genuinely be worried about? These are the very questions we have decided to address.

The baby's fontanelle — what exactly is it?

What lies behind the term "baby's fontanelle" is in fact a soft, membranous area located precisely between the bones of a newborn's skull.

And if you didn't know, there are actually 4 of them in total. Let us explain.

The 4 fontanelles in babies

Indeed, we tend to think that a newborn has only one fontanelle. But that is a misconception! The first — and the main one, it should be said — is what is known as the anterior fontanelle.

It is also the one most easily identified, located at the top of the baby's skull. To give you an idea, it measures roughly between 2 and 5 centimetres.

Next comes what is known as the posterior fontanelle. Smaller in size, it is found at the back of the head, measuring between 0.5 and 1 cm in width.

Then there are what are known as the sphenoidal fontanelles and the mastoid fontanelles, all of which are bilateral.

Now that you know how many fontanelles a baby has and where they are located, what purpose do they actually serve?

The purpose of the baby's fontanelle

Well, fontanelles have two distinct roles to play — and you will see that they are not to be underestimated. First and foremost, the baby's fontanelle facilitates the birth of the child.

Indeed, these soft and flexible areas are able to deform just enough to ease the baby's passage at the right moment — and then return to their original shape, without any difficulty.

The second precious role they play is that the fontanelles allow the brain to continue its development. From birth to two years of age, a newborn's brain will almost double in size.

This naturally raises the question of when a baby's fontanelle closes.

When does it close?

Well, the timeframe can vary from one child to another. The main fontanelle can close anywhere between 1 and 3 years of age — quite a considerable window, it must be said.

As for the posterior fontanelle, it closes fairly quickly — within six to eight weeks, it is already done. For the remaining fontanelles, you can expect closure somewhere between the 3rd and 18th month of the baby's life.

We will finish by sharing the right approach to take.

How to handle the baby's fontanelle

Rest assured! Although this area is soft to the touch, it is equally sturdy — that is worth noting! You can therefore run your hand over it with no risk to your baby whatsoever — whether for a gentle stroke or during bath time. The one thing to avoid, of course, is any knock or impact to that particular area.