How to Check Your Baby’s Fontanelle Correctly: A Definitive Guide for Concerned Parents

Welcoming a newborn into your life is an unparalleled joy, filled with wonder, love, and a natural instinct to protect. Among the myriad of new things you learn about your baby, understanding their fontanelles – those remarkable soft spots on their head – is paramount. These aren’t fragile vulnerabilities to be feared, but rather dynamic windows into your baby’s health and development. This guide aims to demystify the fontanelle, providing you with the knowledge and confidence to correctly assess them, identify potential concerns, and ultimately ensure your little one’s well-being.

Every new parent, at some point, will gaze at their baby’s head with a mixture of awe and apprehension, noticing that pulsating, slightly depressed area. This is perfectly normal. The fontanelle is a testament to the incredible design of the human body, facilitating both the passage through the birth canal and the rapid growth of your baby’s brain. However, like any aspect of your baby’s health, knowing what’s normal and what’s not is crucial. This comprehensive guide will equip you with the practical skills and in-depth understanding to confidently monitor your baby’s fontanelles, transforming potential worry into informed observation.

Understanding the Marvel of the Fontanelle: More Than Just a Soft Spot

Before we delve into the “how-to,” let’s truly appreciate the “what.” A baby’s skull isn’t a single, rigid bone. Instead, it’s composed of several bony plates separated by fibrous joints called sutures. Where these sutures meet, you find the fontanelles. These gaps allow for two critical functions:

Passage Through the Birth Canal: During childbirth, the flexibility provided by the fontanelles and sutures allows the skull bones to overlap slightly, reducing the circumference of the head and making it easier for the baby to navigate the mother’s pelvis. This incredible adaptability is why some newborns might have a slightly cone-shaped head immediately after birth – a temporary phenomenon that quickly resolves.
Brain Growth and Development: A baby’s brain grows at an astonishing rate during the first few years of life. The fontanelles accommodate this rapid expansion, ensuring there’s ample space for the brain to develop without undue pressure. Without these flexible areas, the skull would restrict brain growth, leading to serious developmental issues.

While there are several smaller fontanelles, two are of primary importance for parents to monitor:

The Anterior Fontanelle: This is the larger, diamond-shaped soft spot located on the top front of your baby’s head. It’s the most prominent and the one you’ll primarily be observing. It typically measures between 1 to 4 centimeters in diameter but can vary. This fontanelle usually closes between 12 and 18 months of age, though some can close as early as 9 months or as late as 24 months.
The Posterior Fontanelle: This smaller, triangular-shaped soft spot is located at the back of your baby’s head, closer to the nape of the neck. It’s often less noticeable than the anterior fontanelle and typically closes much earlier, usually by 2 to 3 months of age, and sometimes even at birth.

Understanding the location, purpose, and general timeline for closure of these fontanelles is the first step in confidently assessing them. They are not merely empty spaces; they are dynamic indicators of your baby’s health and the intricate processes unfolding within their rapidly developing body.

The Art of Observation: How to Correctly Check Your Baby’s Fontanelle

Checking your baby’s fontanelle isn’t a complicated medical procedure; it’s an act of gentle observation and parental intuition. It requires a calm approach and an understanding of what to look and feel for. Here’s a step-by-step guide to correctly assessing your baby’s fontanelle:

Step 1: Create a Calm Environment and Position Your Baby Correctly

The first rule of checking your baby’s fontanelle is to ensure your baby is calm and comfortable. A crying, fussy, or excessively active baby can make accurate assessment difficult as their fontanelle might appear more prominent due to increased pressure.

Choose the Right Moment: Ideally, check the fontanelle when your baby is relaxed, perhaps during a quiet feeding, after a nap, or during a gentle cuddle session. Avoid checking immediately after a vigorous crying spell or a strenuous feeding.
Positioning: Gently lay your baby on their back on a flat surface, such as a changing table or a bed, or hold them upright and supported in your arms. Ensure their head is stable and not tilted at an extreme angle. If you’re checking the posterior fontanelle, you might need to gently support their head to expose the back.
Good Lighting: Ensure you have adequate, soft lighting. Direct, harsh light can create shadows that obscure subtle changes. Natural daylight is often ideal.

Step 2: Visual Inspection – The Power of Your Eyes

Before you even touch, observe. Your eyes are your first and often most powerful diagnostic tool.

Locate the Anterior Fontanelle: Gently part any hair on your baby’s head to clearly see the area on the top front of their head. You should easily identify the diamond-shaped soft spot.
Look for Pulsations: It’s completely normal to see a slight pulsation in the fontanelle. This is simply the blood flow to the brain, synchronized with your baby’s heartbeat. Think of it as a subtle, gentle throb.
Assess the Level: This is the most critical visual assessment. The fontanelle should appear mostly flat and level with the surrounding skull. It might have a very slight, almost imperceptible dip, which is normal.
- Sunken Fontanelle (Depressed Fontanelle): If the fontanelle appears noticeably concave, dipping inwards significantly below the level of the surrounding bone, this is a red flag for dehydration. Imagine a small valley forming on your baby’s head.
- Bulging Fontanelle (Tense Fontanelle): If the fontanelle appears outwardly rounded or bulging, raised above the level of the surrounding skull, and feels tense or firm to the touch (even when your baby is calm), this is a serious concern. Imagine a small dome forming on your baby’s head. This can indicate increased intracranial pressure.
Observe Skin Appearance: The skin over the fontanelle should look normal – no redness, swelling (other than a bulge), or unusual discoloration.

Step 3: Gentle Palpation – The Sensitivity of Your Touch

Once you’ve made your visual assessment, gently use your fingertips to feel the fontanelle. Remember, it’s not as fragile as you might imagine, but gentle pressure is key.

Use the Pads of Your Fingers: Use the soft pads of one or two fingers. Avoid using your fingernails or applying excessive pressure.
Feel the Consistency: Gently feel the texture of the fontanelle. It should feel soft and slightly resilient.
- Normal: It should give slightly under your gentle touch, feeling like a firm but pliable membrane. You might feel the pulsations more distinctly.
- Sunken: If sunken, it will feel distinctly hollow or depressed.
- Bulging: If bulging, it will feel firm, tense, and resistant to gentle pressure, almost like a tightly inflated balloon.
Assess the Edges: Gently feel the edges of the fontanelle. You should be able to feel the outline where the bony plates meet the soft spot. The edges should not feel excessively wide or overly narrow for your baby’s age.

Step 4: Repeating the Assessment in Different States

To get a complete picture, it’s often helpful to observe the fontanelle under different conditions, particularly if you have concerns.

During Crying: When a baby cries vigorously, the pressure inside their head temporarily increases, which can cause the fontanelle to appear slightly more prominent or bulge temporarily. This is normal and usually resolves once the baby calms down. The key is that it returns to normal when the baby is quiet. If it remains bulging even after crying stops, it’s a concern.
During Feeding: Observe the fontanelle during and after feeding. If your baby is dehydrated, you might notice the sunken appearance more distinctly during or after a feed, especially if they haven’t been adequately hydrated.

Practical Examples of Normal vs. Abnormal Observations:

Let’s put these observations into concrete scenarios:

Normal Example: You gently lay your 3-month-old on their back. You observe the diamond-shaped soft spot on the top of their head. You see a subtle, rhythmic pulsation. When you gently touch it, it feels soft and slightly yielding, almost level with the surrounding bone, with a very slight dip that’s barely noticeable. Your baby is calm, well-fed, and alert.
Sunken Fontanelle Example: Your 6-month-old has had a persistent fever and diarrhea for 12 hours. You notice they haven’t wet as many diapers as usual and their lips seem a bit dry. When you check their fontanelle, it’s clearly concave, dipping inwards significantly, creating a noticeable valley. When you gently touch it, it feels distinctly hollow. This is a strong indicator of dehydration.
Bulging Fontanelle Example: Your 4-month-old has been unusually irritable, is refusing feeds, and has been excessively sleepy. You notice a rounded, tense prominence on the top of their head where the fontanelle is located. It appears raised above the surrounding bone, and when you gently try to press on it, it feels firm and resistant, almost like a balloon ready to burst. Even when your baby is not crying, it remains distended. This is an urgent medical emergency requiring immediate attention.

By consistently applying these steps and understanding the nuances of normal variations, you’ll become adept at recognizing when your baby’s fontanelle is healthy and when it signals a need for professional medical advice.

When to Seek Medical Attention: Recognizing Red Flags

While minor variations in the fontanelle’s appearance are normal, certain signs should prompt immediate contact with your pediatrician or an emergency medical facility. These are not exhaustive lists, but common red flags:

A. Sunken Fontanelle: Primarily a Sign of Dehydration

A sunken fontanelle is the most common and significant sign associated with dehydration in infants. Dehydration occurs when your baby loses more fluids than they take in, often due to:

Vomiting and Diarrhea: The most frequent culprits.
Fever: Increased body temperature leads to fluid loss through sweating.
Inadequate Fluid Intake: Not feeding enough, especially during illness.
Excessive Sweating: Due to overheating.

Accompanying Symptoms of Dehydration: A sunken fontanelle rarely appears in isolation. Look for these concurrent signs:

Reduced Urine Output: Fewer wet diapers than usual (e.g., less than 6 wet diapers in 24 hours for an infant).
Dry Mouth and Lips: Sticky or parched mucous membranes.
Lack of Tears When Crying: While newborns might not produce many tears initially, older infants should.
Lethargy and Drowsiness: Your baby seems unusually tired, difficult to rouse, or less active.
Sunken Eyes: Eyes appear more hollow or “deep-set.”
Cool, Mottled Skin: Especially in severe cases.
Irritability: Unexplained fussiness that doesn’t resolve with feeding or comfort.
Lack of Skin Elasticity (Poor Skin Turgor): When you gently pinch a fold of skin on their tummy or arm, it takes longer than usual to flatten back down.

When to Act:

Mildly Sunken Fontanelle with Other Mild Symptoms: Contact your pediatrician for advice on increasing fluid intake and monitoring. They might recommend oral rehydration solutions.
Moderately to Severely Sunken Fontanelle with Multiple Dehydration Symptoms: Seek immediate medical attention. Dehydration can quickly become dangerous for infants. Do not wait. This is an emergency.

Example Scenario: Your 8-month-old suddenly develops watery diarrhea and has been vomiting for the past 6 hours. You notice their fontanelle looks distinctly sunken, and they’ve only had one wet diaper in the last 4 hours. Their mouth feels dry. This combination warrants an immediate trip to the emergency room or urgent care.

B. Bulging or Tense Fontanelle: A Serious Indication of Increased Intracranial Pressure

A bulging or tense fontanelle, especially when your baby is calm and not crying, is a medical emergency. It indicates increased pressure inside the skull, which can be caused by various serious conditions, including:

Hydrocephalus: An accumulation of excess cerebrospinal fluid (CSF) in the brain’s ventricles.
Meningitis: Inflammation of the membranes surrounding the brain and spinal cord, often due to a bacterial or viral infection.
Encephalitis: Inflammation of the brain itself.
Intracranial Hemorrhage: Bleeding within the skull, which can occur due to trauma (even minor falls) or certain medical conditions.
Brain Tumors: Although rare in infants, they can cause increased pressure.
Severe Head Trauma: Leading to swelling or bleeding in the brain.

Accompanying Symptoms of Increased Intracranial Pressure: These symptoms often accompany a bulging fontanelle:

Persistent Vomiting: Especially projectile vomiting, not related to feeding issues.
High-Pitched Crying: An unusual, shrill cry.
Irritability and Fussiness: Unconsolable crying or extreme agitation.
Lethargy and Drowsiness: Difficulty waking your baby, or they seem unusually sleepy.
Poor Feeding: Refusal to feed or decreased appetite.
Seizures: Uncontrolled shaking or body stiffening.
Fever: Especially with meningitis.
Stiff Neck: A hallmark symptom of meningitis in some cases.
Bulging Eyes (Sunset Eyes): Eyes that appear to be staring downwards, revealing more of the whites above the iris.
Increased Head Circumference: Rapid growth in head size (your pediatrician will track this at well-child visits).

When to Act:

Anytime a Fontanelle is Bulging and Tense (when the baby is calm): This is an emergency. Seek immediate medical attention at the nearest emergency room. Do not wait for other symptoms to appear. A bulging fontanelle in a calm baby is a critical sign.

Example Scenario: Your 2-month-old has been unusually irritable for the past day, crying with a high-pitched wail. They’ve also had a low-grade fever. You notice the soft spot on their head is visibly bulging and feels very firm to the touch, even when they are asleep. This demands an immediate call to 911 or a rush to the nearest emergency department.

C. Premature Fontanelle Closure (Craniosynostosis):

While less immediately life-threatening than a bulging fontanelle, premature closure of a fontanelle (craniosynostosis) is a condition that requires medical evaluation. This occurs when one or more of the sutures fuse too early, before the brain has finished growing.

What to Look For:
- Absence of a soft spot: The fontanelle feels completely hard to the touch much earlier than expected for your baby’s age (e.g., the anterior fontanelle is completely closed at 6 months).
- Abnormal Head Shape: This is often the most noticeable sign. The head might appear unusually long and narrow, flattened on one side, or have a prominent ridge along a suture line, depending on which suture has fused.
- No Palpable Softness: Where the fontanelle should be, you feel solid bone.

When to Act:

If you suspect premature closure or notice an unusual head shape: Discuss your concerns with your pediatrician during your next well-child visit. They will monitor your baby’s head circumference and may refer you to a specialist (neurosurgeon or craniofacial surgeon) for further evaluation and potential intervention. Early diagnosis is important to ensure optimal brain development.

Example Scenario: Your 6-month-old’s anterior fontanelle feels completely solid, and you can’t detect any soft spot. You also notice that their head seems unusually elongated and narrow. While your baby is developing normally otherwise, these observations warrant discussion with your pediatrician.

D. Delayed Fontanelle Closure:

Less common than premature closure, delayed closure can also be a sign of underlying health issues.

What to Look For:
- Anterior fontanelle remaining open beyond 24 months of age.
- Very large fontanelle for the baby’s age.

Potential Causes:

Hypothyroidism: Underactive thyroid gland.
Down Syndrome: A chromosomal condition.
Rickets: A bone-softening disease caused by vitamin D deficiency.
Hydrocephalus: Can also present with delayed closure if the pressure is not severe enough to cause immediate bulging.

When to Act:

If your baby’s fontanelle is significantly larger than expected for their age or if the anterior fontanelle remains open beyond 2 years: Discuss this with your pediatrician. They will investigate potential underlying conditions through blood tests or imaging.

Example Scenario: Your 2.5-year-old still has a clearly palpable anterior fontanelle, which seems quite large. They’ve also been experiencing some unexplained fatigue and constipation. These symptoms combined with the delayed fontanelle closure should be brought to your pediatrician’s attention.

Debunking Common Fontanelle Myths and Allaying Fears

Fear of harming the fontanelle is a common concern among new parents, leading to unnecessary anxiety. Let’s address some prevalent myths:

Myth 1: You can’t touch a baby’s fontanelle.
- Reality: This is perhaps the most common misconception. While you should always be gentle, the fontanelle is covered by a tough, fibrous membrane and skin, offering significant protection to the brain beneath. You absolutely can and should gently touch and clean your baby’s head, including the fontanelle area. Daily handling, bathing, and even gently brushing their hair will not harm it. Your pediatrician and nurses will touch it during examinations.
Myth 2: A pulsating fontanelle means something is wrong.
- Reality: As discussed, a visible pulsation is completely normal. It’s simply the reflection of blood flowing through the vessels in the brain, synchronized with your baby’s heartbeat. It’s a sign of healthy blood circulation.
Myth 3: Closing the fontanelle too early or too late is always a sign of a serious problem.
- Reality: While both premature and delayed closure can indicate issues, there’s a wide range of normal closure times. Some babies’ anterior fontanelles close as early as 9 months, and others as late as 24 months, all within the normal range. The key is to look at the overall developmental picture and consult your pediatrician if you have specific concerns about your baby’s individual timeline or head shape. It’s the combination of fontanelle appearance with other symptoms that raises a red flag, not solely the timing of closure.
Myth 4: If my baby falls and hits their head, the fontanelle offers no protection.
- Reality: The fontanelle, while soft, is designed to be resilient. While any significant head injury requires medical evaluation, the flexibility of the skull and the presence of the fontanelles actually allow for some give, potentially mitigating certain types of impact compared to a fully rigid skull. However, this doesn’t mean head injuries should be taken lightly. Always seek medical advice after a fall or head trauma.
Myth 5: You should avoid putting hats on your baby because it “suffocates” the fontanelle.
- Reality: This is completely false. A hat provides warmth and protection from the sun. It has no negative impact on the fontanelle or brain development.

By understanding these common misconceptions, you can alleviate unnecessary worry and approach the fontanelle with confidence, seeing it as a normal and functional part of your baby’s anatomy rather than a fragile point of vulnerability.

Beyond the Soft Spot: Complementary Observations for Holistic Health

While closely monitoring the fontanelle is vital, it’s just one piece of the puzzle when assessing your baby’s overall health. A holistic approach involves observing several other key indicators. These observations, when combined with your fontanelle assessment, provide a more complete picture, helping you and your pediatrician identify potential issues early.

Hydration Status: This is intimately linked to the fontanelle’s appearance.
- Wet Diapers: The most reliable indicator. For newborns, expect 6-8 wet diapers a day. For older infants, consistently fewer wet diapers than usual is a concern.
- Tears: As mentioned, the presence of tears when crying (for infants beyond the newborn stage) is a good sign of hydration.
- Moisture of Mucous Membranes: Check your baby’s inner lips and gums. They should appear moist and shiny, not dry, sticky, or parched.
- Skin Turgor: Gently pinch a small fold of skin on your baby’s abdomen. In a well-hydrated baby, the skin should snap back immediately. If it remains tented for a few seconds, it indicates dehydration.
Overall Demeanor and Activity Level:
- Alertness: Is your baby generally alert and engaged with their surroundings when awake?
- Responsiveness: Do they respond to your voice, touch, and toys?
- Irritability: Are they unusually fussy, difficult to comfort, or crying excessively without an obvious reason?
- Lethargy/Drowsiness: Are they unusually sleepy, difficult to wake for feeds, or showing less interest in playing? A significant change in your baby’s normal activity level is a strong indicator of illness.
Feeding Patterns:
- Appetite: Is your baby feeding normally? Are they taking the usual amount of breast milk or formula? A sudden decrease in appetite can be a sign of illness.
- Sucking Reflex: Is their suck strong and consistent?
Temperature:
- Fever: A sudden increase in body temperature can lead to dehydration and is a common symptom of infection. Always take your baby’s temperature if they feel warm. Rectal temperatures are the most accurate for infants.
Vomiting and Diarrhea:
- Frequency and Severity: Monitor the frequency and consistency of your baby’s stools and the frequency and force of vomiting. Persistent vomiting or diarrhea can rapidly lead to dehydration.
Breathing:
- Respiratory Rate: Observe your baby’s breathing rate and effort. Is it unusually fast or labored? Are there any retractions (skin pulling in between the ribs or at the neck)?
- Nasal Flaring: Are their nostrils flaring with each breath?
Fontanelle measurements and Head Circumference:
- While you won’t be measuring these precisely at home, your pediatrician meticulously tracks your baby’s head circumference at every well-child visit. This is a crucial metric for monitoring brain growth and identifying potential issues like hydrocephalus or microcephaly (abnormally small head). If you are concerned about your baby’s head shape or size, discuss it with your pediatrician. They will compare your baby’s measurements to standard growth charts.

By integrating these broader observations with your fontanelle assessment, you create a comprehensive monitoring system for your baby’s health. This allows you to provide your pediatrician with valuable information, leading to more accurate diagnoses and timely interventions when necessary.

The Role of Your Pediatrician: Partnering for Your Baby’s Health

Your pediatrician is your most important partner in monitoring your baby’s fontanelles and overall health. They have the expertise and tools to conduct thorough examinations and interpret findings in the context of your baby’s complete medical history and developmental stage.

Regular Well-Child Visits: These visits are crucial. During each check-up, your pediatrician will:
- Visually Inspect and Palpate the Fontanelles: They will systematically assess the anterior and posterior fontanelles, checking for size, tension, pulsation, and any abnormalities.
- Measure Head Circumference: This is a standard part of every well-child visit. The measurement is plotted on a growth chart, allowing the pediatrician to track the rate of head growth over time. Deviations from normal growth curves (either too fast or too slow) can signal underlying issues related to brain growth or pressure.
- Assess Overall Development: They will evaluate your baby’s milestones, reflexes, and general well-being, all of which contribute to the holistic assessment of health.
Don’t Hesitate to Ask Questions: If you notice anything about your baby’s fontanelle that concerns you, no matter how small, voice it to your pediatrician. There are no silly questions when it comes to your baby’s health.
Trust Your Parental Instincts: You know your baby best. If you feel something isn’t right, even if you can’t pinpoint it, trust that instinct and seek professional medical advice. A parent’s intuition is a powerful diagnostic tool.

For instance, if you’re consistently observing a slight dip in the fontanelle and your baby seems less energetic, even if they’re still wetting diapers, a quick call to your pediatrician is warranted. They might advise you to increase fluid intake or bring your baby in for an assessment. Similarly, if you notice an unusually firm or raised fontanelle, regardless of other symptoms, an immediate medical consultation is imperative. Your proactive observation combined with your pediatrician’s expertise forms the strongest defense for your baby’s health.

Conclusion: Empowered and Confident Parental Care

Monitoring your baby’s fontanelle is a fundamental aspect of informed and confident parental care. Far from being a source of fear, these soft spots are remarkable indicators, offering valuable insights into your baby’s hydration status, intracranial pressure, and overall neurological development. By understanding their purpose, knowing what normal looks and feels like, and being able to identify the warning signs of potential problems, you transform from an anxious observer into an empowered participant in your baby’s health journey.

Remember, the goal is not to become a medical expert, but to develop an astute awareness of your child’s well-being. Regular, calm, and informed observation of the fontanelle, combined with attention to your baby’s overall demeanor, feeding habits, and hydration, forms a powerful early warning system. Partner closely with your pediatrician, sharing any concerns you have, and trust your parental instincts. With this knowledge and a gentle touch, you can confidently navigate the beautiful, sometimes challenging, landscape of newborn care, ensuring your precious little one thrives.