Fontanelle: Everything You Need To Know About Your Baby’s Soft Spot

Fontanelles, commonly called as the baby’s soft spots, can tell something about your baby’s health condition. So what if your baby’s fontanelle seem to be different from other babies? How will you know if it’s already a sign of an underlying problem? Let’s learn more about baby fontanelles, how to care for them, and when will they indicate a need to see the doctor.

What is a fontanelle or soft spot?

The soft areas that you feel in your newborn’s head are called fontanelles (otherwise spelled as fontanels). These are the gaps or spaces in your infant’s skull that will eventually fuse together as babies grow up. The soft spot that most parents refer to is the one on the upper part of their baby’s head, but actually, there are 6 fontanelles on an infant’s skull. These are the following:

Anterior fontanelle

This is found on the top of your baby’s head and the largest of all the fontanelles. It is usually diamond in shape. This fontanelle typically measures around 1 inch and is the most obvious soft spot upon birth.

Posterior fontanelle

This is the triangle-shaped soft spot at the back of your baby’s head. It’s usually less than half of an inch in size, smaller than the one on top of your baby’s head.

Mastoid and sphenoid fontanelles

There are actually skull openings at each side of your baby’s head, but they are less obvious than the first two fontanelles.

The first pair is located on each side of your baby’s head near the temples and these are called the sphenoid fontanelles.

The other pair is called the mastoid fontanelles and they are located behind your baby’s ears.

These soft spots may appear fragile and scary to be touched, but they are purposely made that way to help babies fit in their mother’s birth canal during delivery.

Aside from that, babies have a relatively small skull that will soon grow in size. So these gaps will help accommodate the baby’s increasing head circumference that normally accompanies their growth.

When do fontanelles close?

The bones in the skull won’t completely close during the childhood years because the head will still need some room to grow during this period. However, once the fontanelles or soft spots are no longer palpable, experts consider them as closed.

So when does a baby’s soft spot go away? The time when your baby’s soft spots close depends on the type of fontanelle.

The posterior fontanelle is usually the first one to close. It happens at around 6 to 8 weeks after birth.

The next ones are the sphenoid and mastoid fontanelles which may close at around 6 months of age to 18 months of age.

The last fontanelle to go away is the anterior fontanelle. This baby soft spot may begin to lessen in size at around 6 months of age and usually, can no longer be felt by the time your baby reaches 18 to 24 months of age.

What does a fontanelle normally look like?

A typical baby fontanelle is soft, flat, and may slightly be curved downward. It may slightly be raised when your baby is crying or lying down but should appear flat again once your baby is appeased and positioned upright.

Sometimes, you may also encounter a pulsating fontanelle. You need not to worry about seeing your baby’s soft spot pulsating because it is usually normal and can be more evident when your baby is not that hairy.

How to care for your baby’s soft spot

You may gently touch the top of your baby’s head using your fingers. Some new parents worry about touching their newborn’s head while the fontanelles are open, but don’t worry. Though the skull is not closed yet, there is a thick membrane that cushions and protects the brain and other structures inside the skull.

So even if the baby soft spot is still there, you may shampoo or comb your baby’s hair using a soft-bristled brush. Just be extra gentle in touching your baby’s head. In addition, you may want to refrain from placing any hard and sharp objects near your baby’s head just to prevent any potential injury to happen.

When to worry about your baby’s soft spot

Your baby’s soft spots, particularly the anterior fontanelle, can be an indicator of your baby’s health status. Doctors often check the appearance of this fontanelle in the assessment of newborns. This soft spot may give an idea about the brain and hydration status of your baby. It may also be an indicator of the intracranial pressure or the pressure within a baby’s head.

You will need to see a doctor when your baby’s soft spot appear this way:

Sunken fontanelle

A sunken or depressed fontanelle may be a sign of dehydration. Dehydration happens when your baby has less than the ideal fluid levels in the body. Babies who have persistent diarrhea or vomiting episodes are at risk of dehydration.

If your baby’s fontanelle appear to be sunken but he is feeling well and active, try to nurse your baby and see if it resolves. However, if your baby is having loose bowel movements, is vomiting, or is not feeding, these are red flags and you need to see a pediatrician immediately. Dehydration can be life-threatening to babies and prompt treatment is required.

Swollen fontanelle

A swollen soft spot after an accidental fall can be a sign of head injury, especially if it is followed by an episode of vomiting. You’ll need to bring your baby to the doctor right away so that proper assessment and treatment can be given.

Bulging fontanelle

If your baby’s soft spot seems to be bulging, it can indicate an increase in pressure within the head due to fluid build-up or mass. It may also be a sign of a condition called hydrocephalus which causes fluid accumulation and rapid growth of an infant’s head.

It is best to see a doctor immediately if your baby has a bulging fontanelle, especially when it is noticed along with vomiting, fatigue, and a change in your baby’s alertness.

Sometimes, doctors will need to perform a procedure called shunting, to remove any excess fluids and relieve the pressure within the skull.

Early closure of fontanelle

Though babies may slightly differ in the time when their soft spots will close, a fontanelle closure too early than what is normal among babies may pose problems in your baby’s head development.

For example, a condition called craniosynostosis may cause asymmetrical growth of a baby’s head because the fontanelle on one side have fused too early than the other side. This will lead to abnormally shaped head, such as a football shape.

This condition can’t be checked by parents alone because sometimes, babies simply have a “quiet fontanelle”. In this case, the fontanelles are still open but they are not as obvious as that of other babies. Quiet fontanelles aren’t harmful. As long as your baby’s head is growing normally and he is feeling well, there’s not so much to be worried about.

However, if you notice that your baby’s head seems to grow a bit odd, you may seek help from a doctor. If your baby’s fontanelle has really closed too early, then a surgical intervention may be required to correct the shape of your baby’s head.

Baby soft spot not closing

If the fontanelles are not decreasing in size by the time your baby reached his or her first birthday, you may need to consult a doctor. A fontanelle that remains big and open for a long time can be an indicator of a genetic disorder called congenital hypothyroidism.


A newborn soft spot or fontanelle is the most obvious reminder that babies are fragile and need special care and attention. If you have concerns about the appearance or closure of your baby’s fontanelle, it will be best to verbalize it with your pediatrician. This way, your concern will be properly addressed and you’ll be given an expert’s advice regarding your baby’s health.



This article is for informational purposes only and should not be considered medical advice. Always consult with a doctor or licensed medical professional before making any medical decisions.

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