Newborn Soft Spot: Fontanelle Facts Every Parent Should Know
Share
Quick Answer
The soft spot on your baby's head is a normal opening between the developing bones of the skull called a fontanelle.
A newborn usually has a larger soft spot near the top-front of the head and a much smaller one toward the back. These fontanelles allow the skull to accommodate rapid brain growth during infancy.
The soft spot may feel flat or slightly curved inward, and you may occasionally see it gently pulsate. Those findings can be normal.
A markedly sunken soft spot can occur with dehydration, while a tense or persistently bulging soft spot when a baby is calm and upright requires prompt medical attention.
Key Takeaways
- A baby's soft spot is called a fontanelle.
- Newborns normally have more than one fontanelle.
- The larger anterior fontanelle is located toward the top-front of the baby's head.
- The smaller posterior fontanelle is toward the back of the head and generally closes much earlier.
- You can safely touch and gently wash your baby's head over the soft spot.
- Seeing a gentle pulse in the fontanelle can be normal.
- A significantly sunken fontanelle can be associated with dehydration.
- A persistently tense or bulging fontanelle when a baby is calm deserves prompt medical attention.
Few things make a new parent more nervous than the soft spot on a newborn's head. You may notice it while washing your baby's hair, see it move slightly with each heartbeat, or accidentally touch it and immediately wonder whether you could have hurt your baby.
The reassuring news is that a baby's soft spots are a normal and important part of the developing skull. Whether you've heard it described as a baby's head fontanelle, a newborn fontanelle, or simply the soft spot on your baby's head, these terms refer to a normal part of early skull development.
Understanding what the fontanelle is—and what it normally looks and feels like—can make this unusual feature of newborn anatomy much less intimidating.
What Is the Soft Spot on a Baby's Head?
The medical term for a baby's soft spot is a fontanelle. A newborn's skull is not one solid piece of bone. Instead, it is made of several bones separated by flexible seams called sutures.
Where several of these sutures meet, there are membrane-covered spaces known as fontanelles. These flexible areas help the baby's head adapt during birth and, importantly, allow room for the brain and skull to grow rapidly during infancy.
Although the area feels soft compared with the surrounding skull, it is covered by a strong protective membrane.
Where Is a Newborn's Fontanelle?
The two soft spots parents are most likely to hear about are the anterior fontanelle and posterior fontanelle.
The Anterior Fontanelle
The anterior fontanelle is the larger soft spot located toward the top-front of your baby's head. It is often described as diamond-shaped and is usually the soft spot parents notice most easily when touching or washing their baby's head.
The Posterior Fontanelle
The posterior fontanelle is much smaller and located farther toward the back of the head. Because it is small and normally closes relatively early, many parents never notice it.
Why Do Babies Have Soft Spots?
Fontanelles serve an important purpose. During birth, the bones of a baby's skull need some flexibility. The sutures and fontanelles allow the skull bones to shift slightly as the baby's head passes through the birth canal.
After birth, that flexibility remains important because a baby's brain and skull grow rapidly. Over time, the skull bones enlarge, the fontanelles gradually become smaller, and eventually the spaces close.
When Does a Baby's Soft Spot Close?
The two main fontanelles do not close at the same time, and there is normal variation from baby to baby.
The small posterior fontanelle usually closes during the first few months of life, often around 2 to 3 months.
The larger anterior fontanelle remains open much longer. It commonly closes between about 12 and 18 months, although a broader range can still be normal.
Your pediatrician checks the fontanelle, head circumference, and skull growth during routine well-child visits. The important point is that there is not one exact day or month when every baby's soft spot must disappear.
Can I Touch My Baby's Soft Spot?
Yes. Parents sometimes treat the fontanelle as though the baby's brain is directly underneath an unprotected opening, but that isn't the case. A strong fibrous membrane covers the fontanelle and protects the structures beneath it.
Normal gentle handling is safe. You can:
- wash your baby's scalp
- shampoo the hair
- gently brush the hair
- touch the scalp
- hold and cuddle your baby normally
You don't need to avoid the soft spot during routine care.
Why Is My Baby's Soft Spot Pulsating?
Parents sometimes notice the soft spot moving or gently pulsating, which can look alarming the first time you see it.
A visible pulse can be normal. The flexible tissue over the fontanelle can allow you to see pulsation that corresponds with your baby's heartbeat.
If your baby otherwise looks comfortable and well, seeing a gentle rhythmic pulse in the soft spot is usually not concerning.
Should a Baby's Soft Spot Be Flat?
When your baby is calm and upright, the fontanelle generally feels relatively flat or may curve slightly inward. Its appearance can temporarily change depending on your baby's position and behavior.
For example, the fontanelle may appear fuller when a baby is:
- crying
- lying down
- straining
- vomiting
What matters is how the soft spot looks once your baby is calm and in a head-up position.
What Does a Sunken Soft Spot Mean?
A noticeably sunken soft spot can be associated with dehydration, but don't evaluate dehydration from the fontanelle alone. Look at the whole baby.
Other possible signs of dehydration include:
- fewer wet diapers than usual
- dry mouth
- poor feeding
- unusual sleepiness or decreased activity
- few or no tears when crying
- repeated vomiting or diarrhea
What Parents Can Do at Home
You do not need to repeatedly press or check your baby's fontanelle. Instead, pay attention to your baby's overall behavior, feeding, urine output, and general appearance.
- Feed your baby normally.
- Keep track of wet diapers when your baby is sick.
- Watch for repeated vomiting or diarrhea.
- Notice significant changes in feeding or activity.
- Continue normal gentle bathing and scalp care.
If you think the soft spot looks significantly different from usual—or your baby simply doesn't look well—contact your pediatrician.
What Does a Bulging Soft Spot Mean?
A fontanelle can temporarily look fuller when a baby cries, strains, vomits, or lies flat. That is different from a fontanelle that remains tense or bulging when the baby is calm and in a head-up position.
A truly bulging fontanelle can occur when pressure inside the skull is increased and can accompany serious illness. This is not something parents need to diagnose themselves.
If your baby's soft spot remains tense or bulging when your baby is calm and head-up, seek prompt medical evaluation. If the bulging fontanelle occurs along with fever, unusual drowsiness, decreased responsiveness, repeated vomiting, seizure, or a seriously ill appearance, seek emergency medical care.
What If My Baby's Soft Spot Seems Too Big?
Fontanelle size varies among healthy babies. Your pediatrician evaluates more than the size of the soft spot. We also look at your baby's head circumference, growth pattern, skull shape, sutures, development, and overall examination.
An unusually large fontanelle can sometimes occur with certain medical or developmental conditions, but size alone does not establish a diagnosis. If your pediatrician believes the fontanelle is unusually large or is not changing as expected, they may monitor it over time or investigate further.
What If My Baby's Soft Spot Closes Early?
Parents sometimes notice that they can no longer easily feel the fontanelle and worry that it has closed too soon. Fontanelle closure varies considerably.
What matters is not simply whether you can feel a soft spot. Pediatricians also follow the baby's head circumference, skull shape, and growth pattern over time.
If there is concern about unusually early closure of the skull sutures or an abnormal head shape, your pediatrician will evaluate your baby's head growth and examination more closely.
Why Does My Pediatrician Feel the Soft Spot?
Checking the fontanelle is a routine part of many infant examinations. Your pediatrician may assess:
- the size of the fontanelle
- whether it feels soft, flat, sunken, or tense
- the shape of the skull
- the skull sutures
- head circumference and growth over time
We don't interpret any of these findings in isolation. The fontanelle is simply one piece of the overall examination.
When to Call Your Pediatrician
Contact your pediatrician if:
- your baby's soft spot appears significantly more sunken than usual
- your baby has fewer wet diapers or other signs of dehydration
- the fontanelle seems unusually large or you have concerns about how it is closing
- your baby's head shape or head growth concerns you
- you notice a persistent change in the appearance of the soft spot
- your baby is feeding poorly or acting unusually
You do not need to decide whether a fontanelle is abnormal before calling. If something looks different and concerns you, your pediatrician can help determine whether it needs evaluation.
Seek Urgent Medical Care If
A truly tense or persistently bulging soft spot when your baby is calm and in a head-up position requires prompt medical evaluation.
Seek emergency medical care if a bulging fontanelle occurs along with:
- fever
- difficulty waking or unusual drowsiness
- marked irritability or decreased responsiveness
- repeated vomiting
- a seizure
- significant weakness
- trouble breathing
- a seriously ill appearance
Any fever of 100.4°F (38°C) or higher in a baby younger than 3 months requires prompt medical evaluation, regardless of how the soft spot looks.
Dr. G's Pearl
Your baby's soft spot is not as fragile as it looks.
I understand why parents are nervous about it. You can feel something soft where you expect to feel bone, and sometimes you can even see it pulse. But the fontanelle is supposed to be there. It is protected, and it serves an important purpose while your baby's brain and skull are growing rapidly.
So wash your baby's hair. Gently touch their head. Give them all the cuddles you want.
You don't need to be afraid of the soft spot—you just need to know what changes deserve attention.
Frequently Asked Questions About Baby Soft Spots
What is the soft spot on a baby's head called?
It is called a fontanelle. Fontanelles are normal membrane-covered spaces between the developing bones of a baby's skull.
How many soft spots does a newborn have?
Several fontanelles are present anatomically, but the two parents most commonly hear about are the larger anterior fontanelle near the top-front of the head and the smaller posterior fontanelle toward the back.
When does a baby's soft spot close?
The small posterior fontanelle usually closes during the first few months, often around 2 to 3 months. The larger anterior fontanelle commonly closes around 12 to 18 months, although normal timing varies.
Can I touch my baby's soft spot?
Yes. A strong fibrous membrane protects the area. Normal gentle touching, bathing, shampooing, and brushing are safe.
Why can I see my baby's soft spot pulsating?
A gentle rhythmic pulse can be normal. The flexible tissue over the fontanelle can allow you to see pulsation that corresponds with your baby's heartbeat.
What does a sunken soft spot mean?
A significantly sunken fontanelle can occur with dehydration. Look for other signs such as fewer wet diapers, poor feeding, dry mouth, vomiting, diarrhea, or unusual sleepiness rather than judging hydration from the soft spot alone.
What does a bulging soft spot mean?
Crying, vomiting, or lying down can temporarily make the fontanelle appear fuller. A fontanelle that remains tense or bulging while a baby is calm and head-up requires prompt medical evaluation.
Can crying make the soft spot bulge?
Yes. Crying, straining, vomiting, or lying flat can temporarily make the fontanelle look fuller. It should return toward its usual appearance once your baby is calm and head-up.
What if I accidentally touch or press my baby's soft spot?
Normal gentle contact is unlikely to harm your baby because a strong membrane protects the area. Significant head trauma is different and should be evaluated based on the circumstances and your baby's symptoms.
Why does the pediatrician measure my baby's head?
Head circumference allows your pediatrician to follow skull and brain growth over time. The growth pattern is interpreted along with the fontanelle, skull shape, development, and the rest of your baby's examination.
The Bottom Line
The soft spot on your baby's head, or fontanelle, is a normal part of infant anatomy. Fontanelles give the rapidly growing brain and skull room to develop, and they gradually close as your baby grows.
A soft, relatively flat fontanelle—and even a gentle visible pulse—can be completely normal. What deserves attention is a significant change, particularly a markedly sunken fontanelle along with other signs of dehydration or a persistently tense, bulging fontanelle when your baby is calm and head-up.
And remember: you can safely touch, wash, and cuddle your baby's head.
Join the Parent Club
Parenting comes with hundreds of questions. Get trusted pediatric guidance from Dr. G designed to help you understand what's normal, what you can do at home, and when it's time to call your pediatrician.
Join the Parent Club →References
- American Academy of Pediatrics, HealthyChildren.org. Your Baby's Head. HealthyChildren.org
- American Academy of Pediatrics, HealthyChildren.org. Newborn Appearance Questions. HealthyChildren.org
- American Academy of Pediatrics, HealthyChildren.org. Signs of Dehydration in Infants & Children. HealthyChildren.org
- MedlinePlus Medical Encyclopedia. Fontanelles — Bulging. MedlinePlus
- MedlinePlus Medical Encyclopedia. Fontanelles — Sunken. MedlinePlus
- American Academy of Pediatrics. Bright Futures: Guidelines for Health Supervision of Infants, Children, and Adolescents.
Related Parent Resources
Related Parent Resources
More guidance on closely related questions parents often ask.