Where Is The Soft Spot On A Baby’s Head? A baby’s soft spot, called the fontanelle, is found in two main places: the top front of the head (anterior fontanelle) and the back of the head (posterior fontanelle). These areas are gaps between the skull bones, covered by strong membranes that help the baby’s head remain flexible during birth and make room for rapid brain growth. Learn how to check these soft spots to make sure your baby’s skull is developing well and to notice any signs that may need a doctor’s attention.
What Is The Softest Part Of A Baby’s Head?
The softest part of a baby’s head is called the fontanelle, or “soft spot.” These areas are small gaps between the skull bones, covered by a thick, fibrous membrane. They let the skull flex during birth and make room for the growing brain. 1
Even though they feel softer than the surrounding bone, biomechanical studies show that open fontanelles actually help spread out forces across the skull, acting as a built‑in shock absorber rather than a weak spot. 2
Because these areas aren’t covered by bone, doctors can also use the softest part of the head as an ultrasound “window” to examine the brain and fluid spaces in young infants without radiation. 3
Where Is The Soft Spot On A Baby’s Head?
he soft spot on a baby’s head is called the fontanelle. It plays an important role in how a baby’s skull grows after birth. Most babies have two main soft spots. 4
1- The bigger soft spot, “anterior fontanelle,” is located at the top front of the head. Start at the middle of your baby’s forehead and slide your fingers straight up. Before the head starts to slope toward the back, you may feel a small, soft, slightly bouncy area.
2-The smaller posterior fontanelle is found at the back of the head. Find the little bump at the back of the skull, then move your fingers up toward the top. Just above this bump, some babies have a tiny soft triangle. In other babies, this spot may already feel firm.
These areas are where the skull bones, or skull plates, have not yet fused together, leaving gaps covered by tough membranes. This design allows the baby’s skull to be flexible enough to pass through the narrow birth canal during vaginal delivery and accommodates the rapid brain growth that occurs in the first year of life.
Supporting healthy skull development also means giving your baby enough floor time. Find out why tummy time matters for infant development and how it supports your baby’s growing head and neck.
Newer studies that model baby heads on computers show that the size and shape of these soft spots can change how the head reacts to bumps. Because the soft spots and seams between the bones can flex, they help spread some of the force instead of sending it straight to one spot, adding another layer of protection while your baby’s skull is still growing.5
Doctors check these soft spots during regular visits to make sure the baby’s skull is developing well. They also measure the baby’s head size and look at the fontanelles to track growth.
As the fontanelles gradually close, you may also notice your baby gaining more control over their head movements. Learn more about when babies start holding their head up and what that milestone means for their development.
What Should The Soft Spot On a Baby’s Head Feel like?
The soft spot on a baby’s head, or fontanelle, should feel soft, flat, and slightly pliable to the touch. It is normal to feel a gentle pulsation in rhythm with your baby’s heartbeat, caused by normal blood flow through the blood vessels beneath the membrane covering the fontanelle. If that pulse feels much stronger or unusually fast, check with a healthcare provider. 6
This pulsation is a healthy sign and indicates good circulation. The surrounding skull plates meet at the edges of the fontanelle, providing a firm boundary that protects the brain underneath.
The soft spot can look a bit fuller when your baby is lying flat, crying hard, or straining, and then go back to flat once they calm down. Because of this, doctors check the soft spot when babies are quiet and either sitting up or held upright. If the soft spot looks raised and tense even when your baby is calm, that is more concerning than a brief change during a cry.
When doctors feel your baby’s soft spot, they sort what they feel into simple groups. A normal soft spot feels soft and flat or only slightly lower than the bone around it. A tense or bulging soft spot feels tight and stands up above the skull, like a drum skin stretched tight, in a calm baby. A sunken soft spot feels more like a deep dip compared with the nearby bone. They use this, plus your baby’s behavior and other signs, to decide if there is a problem.7
How Fragile Are Babies’ Soft Spots?
Despite their delicate appearance, babies’ soft spots are surprisingly resilient. The flexible bony plates of the newborn baby’s skull also help the head passes more easily through the birth canal while making room for the growing brain. 8
The fontanelles are covered by a thick, durable layer of fibrous tissue that protects the brain underneath, allowing for normal daily handling without causing injury. This protective membrane means that gentle touching, such as when washing your baby’s hair or supporting their head and neck, is safe and will not harm the baby.
How to care for a baby’s soft spot?
Caring for a baby’s soft spot (fontanelle) simply requires gentle, routine handling. You do not need to avoid touching the area. Just be cautious when washing, brushing, or placing hats on your baby’s head, and always support their neck to prevent accidental bumps.
How do I protect my baby’s soft spot?
For new parents, that means you can gently care for your little one, and remind friends or other caregivers to handle your little one’s head gently too.
When Does Soft Spot Close?
The baby’s fontanelles close at different ages depending on their location and individual development.
The smaller posterior fontanelle, located at the back of the head, usually closes first, typically by the time the baby is about 2 to 3 months old. In some cases, it may even be closed at birth.
This early closure happens during one of the most physically intense periods of your baby’s life. See how long the newborn stage lasts and what changes to expect as your baby grows out of it.
The larger anterior fontanelle, found at the top front of the head, remains open longer because these open spaces let the baby’s skull grow rapidly around the growing brain during infancy. This soft spot generally closes between 4 and 26 months of age, with many babies’ anterior fontanelles closing around 18 months.9
Fontanelles, or soft spots on a baby’s head, close at different times for each child. Sometimes, boys’ fontanelles close a bit earlier than girls’. It is important that these soft spots do not close too soon, since the gradual joining of the skull bones supports healthy growth.
Pediatricians routinely monitor the fontanelles during checkups to ensure they are closing appropriately and to detect any potential issues. If a baby’s fontanelles do not close by age 2, the child should be evaluated by the child’s healthcare provider.
What Happens If A Baby Hits A Soft Spot On Top Of His Head?
If a baby hits the soft spot on top of their head, it can be understandably alarming for parents and caregivers. However, due to the protective membranes covering the fontanelles, the brain is shielded from minor bumps and everyday handling.
Gentle impacts or accidental bumps typically do not cause harm. Nonetheless, significant trauma or a strong blow to the soft spot area can lead to swelling, bruising, or a bulging soft spot, which may indicate increased pressure inside the skull.
In cases of head trauma, watch for signs of distress such as nonstop crying, vomiting, changes in sleep, unusual irritability, or difficulty waking.
A bulging soft spot after injury may indicate serious issues like bleeding or fluid buildup in the brain and requires immediate medical attention.
Not sure if your baby’s soft spot looks normal?
Avocado Health is always available. No app. No waitlist.
- Help knowing when to wait, when to worry, and when to see a doctor
- Instant answers at 2am when your child is sick and you can’t reach a doctor
- Evidence-based answers from a team of pediatric and parenting experts
- Remembers your child’s name, age, and history. Personalized guidance, not generic tips
What Happens If A Baby’s Soft Spot Never Closes?
If a baby’s fontanelles do not close within the expected timeframe, typically by 18 to 26 months for the anterior fontanelle, further evaluation by a healthcare provider is needed.
Persistent open fontanelles may be associated with conditions such as hypothyroidism, rickets, increased intracranial pressure, or genetic disorders that impact bone growth and development. For example, hypothyroidism can slow down bone growth and delay the closing of soft spots. Rickets, which happens when there is not enough vitamin D, can make bones weaker and change how the skull forms. 10
Problems can also occur if the bones in the baby’s skull fuse too soon, which may affect head shape and development.
Can Soft Spots Indicate A Health Problem?
Changes in a baby’s soft spots can sometimes signal health problems affecting the baby’s body as a whole. A soft spot that pulses gently with the baby’s heartbeat is normal, but a stronger pulse or a bulging appearance can point to increased pressure in one’s head or follow an injury. 11
What are the warning signs of a bulging soft spot?
- A sunken soft spot often means the baby is dehydrated. This can happen if the baby is not drinking enough fluids or breast milk.
- A bulging fontanelle can mean there is increased pressure inside the skull. This can happen due to head trauma, infections like meningitis, or fluid buildup in the brain called hydrocephalus, and it needs immediate medical attention, especially if the baby is vomiting or has changes in behavior or temperament.
- If a soft spot closes too early or stays open too long, it could mean conditions like craniosynostosis or hypothyroidism.
How To Tell If A Fontanelle Is Sunken?
A sunken fontanelle, also known as a sunken soft spot, can be an important indicator of your baby’s hydration status.
What does a dehydrated soft spot look like?
It occurs when the soft spot on your baby’s head appears to dip inward or looks noticeably lower than the surrounding skull. This condition often signals dehydration, which can happen if your baby is not getting enough fluids, such as enough breast milk or formula, or if they are losing fluids due to illness like vomiting or diarrhea.
Conclusion
The soft spot on a baby’s head is a normal part of their development. It helps the skull grow and protects the brain. Parents should gently care for it and watch for signs like sunken or bulging spots. If you notice anything unusual, contact your child’s doctor to ensure your baby’s health and safety.
Frequently Asked Questions
What happens if you accidentally press the soft spot on a baby’s head?
Accidentally pressing the soft spot on a baby’s head is generally not harmful. The fontanelles are covered by a thick, durable membrane that protects the delicate brain tissue underneath. This membrane, along with the surrounding skull bones, provides a strong barrier against everyday gentle pressure. Therefore, normal handling, such as holding your baby, washing their hair, or light touching, will not cause injury or pain.
Why is my baby’s soft spot not pulsating?
It is completely normal for a baby’s soft spot (fontanelle) to sometimes appear to stop pulsating. The pulsing itself is simply healthy blood flow matching the baby’s heartbeat, but it often becomes much harder or impossible to see with the naked eye, depending on the lighting, the angle, and whether the baby is crying or sitting completely still.
As your baby grows, the soft spot slowly gets smaller, and the skull bones thicken. This makes the pulse much harder to see, so many older babies have a normal soft spot that you can’t see pulsing at all
Sources:
- Growth charts of sutures and fontanelles for the first year of infancy
- nfluence of suture and fontanelle morphological variabilities on infant head injury biomechanics
- Cranial sutures
- Influence of suture and fontanelle morphological variabilities on infant head injury biomechanics
- Allometry of human calvaria bones during development from birth to 8 years of age shows a nonlinear growth pattern
- Fontanelles – bulging
- Dehydration
- Anatomy, Head and Neck: Fontanelles
- Difference in anterior fontanelle closure between non-syndromic craniosynostosis and normal controls: a retrospective cross-sectional study
- The neurodevelopmental profile of healthy children with premature anterior fontanel closure
- What To Know About Baby’s Fontanelles