Pulsing Soft Spot (Fontanelle) in Newborns
Medically reviewed by Dr. Michael Okonkwo, MD, FAAP · Board-Certified Neonatologist
Content reviewed against published AAP, NIH guidelines
Last reviewed:
If your baby has been diagnosed with or you suspect pulsing soft spot (fontanelle) in newborns, here is what the evidence says.
The short answer
A pulsing or throbbing soft spot (fontanelle) on your newborn's head is completely normal. The pulsation you see is the heartbeat transmitted through the blood vessels beneath the thin membrane covering the fontanelle. This is a reassuring sign that your baby's circulatory system is functioning well. The fontanelle should be flat or slightly concave when your baby is calm and upright.
Key takeaways
- A pulsing or throbbing soft spot (fontanelle) on your newborn's head is completely normal. The pulsation you see is the heartbeat transmitted through the blood vessels beneath the thin membrane covering the fontanelle. This is a reassuring sign that your baby's circulatory system is functioning well. The fontanelle should be flat or slightly concave when your baby is calm and upright.
- Usually normal when: Visible pulsation of the soft spot that matches your baby's heartbeat
- Call your doctor if: A persistently bulging or tense fontanelle when baby is calm and upright, which could indicate increased intracranial pressure from infection (meningitis) or hydrocephalus
- Varies by age — see the age-by-age breakdown below
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What Parents Should Know
According to AAP, NIH guidelines, a pulsing or throbbing soft spot (fontanelle) on your newborn's head is completely normal. The pulsation you see is the heartbeat transmitted through the blood vessels beneath the thin membrane covering the fontanelle. This is a reassuring sign that your baby's circulatory system is functioning well. The fontanelle should be flat or slightly concave when your baby is calm and upright. At 0-1 month, the anterior fontanelle (the larger soft spot on top of the head) and posterior fontanelle (the smaller one toward the back) are normal openings between the skull bones. The visible pulsation is your baby's heartbeat transmitted through blood vessels beneath the fontanelle membrane. This is completely normal and expected. A normal fontanelle is flat or slightly concave when baby is calm and upright. It may bulge slightly when baby cries or strains, which is also normal. It is generally considered normal when visible pulsation of the soft spot that matches your baby's heartbeat. However, you should contact your pediatrician promptly if a persistently bulging or tense fontanelle when baby is calm and upright, which could indicate increased intracranial pressure from infection (meningitis) or hydrocephalus.
Normal vs. Concerning
By Age
What to expect by age
0-1 month
The anterior fontanelle (the larger soft spot on top of the head) and posterior fontanelle (the smaller one toward the back) are normal openings between the skull bones. The visible pulsation is your baby's heartbeat transmitted through blood vessels beneath the fontanelle membrane. This is completely normal and expected. A normal fontanelle is flat or slightly concave when baby is calm and upright. It may bulge slightly when baby cries or strains, which is also normal.
1-3 months
The posterior fontanelle typically closes by 2-3 months. The anterior fontanelle remains open and may continue to show visible pulsation, which remains normal. Continue to be aware of the fontanelle's appearance: it should remain soft and flat when your baby is calm.
3-6 months
The anterior fontanelle remains open and pulsation may still be visible. This is normal. The fontanelle will gradually become smaller as the skull bones grow together. It typically closes between 9-18 months of age.
6-12 months
The anterior fontanelle is still open and may begin to gradually close. Pulsation may be less visible as the opening decreases in size. Complete closure typically occurs between 12-18 months. Your pediatrician checks the fontanelle at each well-child visit.
What to Tell Your Pediatrician
- Describe when you first noticed pulsing soft spot (fontanelle) in newborns and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if the fontanelle appears to be closing very early (before 6 months) or very late (after 18 months).
- Mention if you notice the fontanelle seems unusually large or small.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
What Should You Do?
When to take action
- Visible pulsation of the soft spot that matches your baby's heartbeat
- Fontanelle that is flat or slightly concave when baby is calm and upright
- Slight bulging of the fontanelle when baby cries or strains that resolves when calm
- Both the pulsation and the soft spot itself are present and expected
- The fontanelle appears to be closing very early (before 6 months) or very late (after 18 months)
- You notice the fontanelle seems unusually large or small
- You are unsure whether the fontanelle appearance is normal
- A persistently bulging or tense fontanelle when baby is calm and upright, which could indicate increased intracranial pressure from infection (meningitis) or hydrocephalus
- A significantly sunken fontanelle, which can be a sign of dehydration, especially if baby is also feeding poorly or has fewer wet diapers
What You Can Do at Home
- Keep track of when you notice pulsing soft spot (fontanelle) in newborns — noting the time of day, duration, and any triggers can help your pediatrician.
- Remember that visible pulsation of the soft spot that matches your baby's heartbeat — this is generally within the range of normal.
- At 0-1 month, focus on observation rather than intervention unless your pediatrician advises otherwise.
- Follow any care instructions from your pediatrician. Keep a written log of symptoms to bring to appointments.
- While monitoring at home, seek immediate care if a persistently bulging or tense fontanelle when baby is calm and upright, which could indicate increased intracranial pressure from infection (meningitis) or hydrocephalus.
Related Conditions
Cone-Shaped Head After Vaginal Birth (Head Molding)
A cone-shaped or elongated head after vaginal birth is very common and completely normal. It is called head molding and occurs because the bones of your baby's skull are not yet fused, allowing them to overlap and shift to fit through the birth canal. Your baby's head will round out naturally within a few days to weeks.
I'm Worried About Craniosynostosis
Craniosynostosis occurs when one or more of the fibrous joints (sutures) between a baby's skull bones close prematurely, affecting head growth and shape. It occurs in about 1 in 2,000-2,500 births. While it requires surgical treatment, outcomes are generally excellent when diagnosed and treated early. Not all abnormal head shapes are craniosynostosis - positional plagiocephaly is far more common.
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
Related Resources
Frequently asked questions
Is pulsing soft spot (fontanelle) in newborns normal?
When should I call the doctor about pulsing soft spot (fontanelle) in newborns?
When is pulsing soft spot (fontanelle) in newborns normal?
What causes pulsing soft spot (fontanelle) in newborns?
What should I mention to my pediatrician about pulsing soft spot (fontanelle) in newborns?
Is pulsing soft spot (fontanelle) in newborns normal at 0-1 month?
Is pulsing soft spot (fontanelle) in newborns normal at 1-3 months?
Should I go to the ER for pulsing soft spot (fontanelle) in newborns?
Does pulsing soft spot (fontanelle) in newborns go away on its own?
References
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss Pulsing Soft Spot (Fontanelle) in Newborns.
Things to mention
- Describe when you first noticed pulsing soft spot (fontanelle) in newborns and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if the fontanelle appears to be closing very early (before 6 months) or very late (after 18 months).
- Mention if you notice the fontanelle seems unusually large or small.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
Observations to share
- The fontanelle appears to be closing very early (before 6 months) or very late (after 18 months)
- You notice the fontanelle seems unusually large or small
- You are unsure whether the fontanelle appearance is normal
Urgent signs to report immediately
- A persistently bulging or tense fontanelle when baby is calm and upright, which could indicate increased intracranial pressure from infection (meningitis) or hydrocephalus
- A significantly sunken fontanelle, which can be a sign of dehydration, especially if baby is also feeding poorly or has fewer wet diapers
My notes
From ismybabyalright.com — free, evidence-based baby health guides
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members
Related Resources
Bottom line
Most cases of pulsing soft spot (fontanelle) in newborns are normal. Talk to your pediatrician if a persistently bulging or tense fontanelle when baby is calm and upright, which could indicate increased intracranial pressure from infection (meningitis) or hydrocephalus.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
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Related Medical Concerns
Cone-Shaped Head After Vaginal Birth (Head Molding)
A cone-shaped or elongated head after vaginal birth is very common and completely normal. It is called head molding and occurs because the bones of your baby's skull are not yet fused, allowing them to overlap and shift to fit through the birth canal. Your baby's head will round out naturally within a few days to weeks.
I'm Worried About Craniosynostosis
Craniosynostosis occurs when one or more of the fibrous joints (sutures) between a baby's skull bones close prematurely, affecting head growth and shape. It occurs in about 1 in 2,000-2,500 births. While it requires surgical treatment, outcomes are generally excellent when diagnosed and treated early. Not all abnormal head shapes are craniosynostosis - positional plagiocephaly is far more common.
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
Achondroplasia (Dwarfism) in Babies
Achondroplasia is the most common form of short-limbed dwarfism, affecting about 1 in 15,000 to 40,000 births. It is caused by a mutation in the FGFR3 gene and is usually apparent at birth with characteristic features including short limbs, a larger head, and a prominent forehead. Intelligence is normal. With monitoring for specific complications and supportive care, children with achondroplasia lead full, active, and independent lives.
Adenoid Hypertrophy and Breathing
Adenoids are lymphoid tissue located behind the nose that help fight infection in young children. When adenoids become enlarged (adenoid hypertrophy), they can block the nasal airway, causing chronic mouth breathing, snoring, nasal speech, and sleep-disordered breathing. Enlarged adenoids are most common between ages 2-7 and are a leading cause of obstructive sleep apnea in young children. Treatment ranges from watchful waiting and nasal steroids to surgical removal (adenoidectomy) if breathing or sleep is significantly affected.
Adrenoleukodystrophy (ALD) in Babies
X-linked adrenoleukodystrophy (X-ALD) is a genetic disorder affecting about 1 in 17,000 newborns, caused by mutations in the ABCD1 gene on the X chromosome. It primarily affects boys and impairs the breakdown of very long-chain fatty acids (VLCFAs), which accumulate and damage the myelin sheath in the brain and the adrenal glands. The most severe form, cerebral ALD, typically affects boys between ages 4-10 with rapid neurological decline. Newborn screening now enables early detection, and hematopoietic stem cell transplant or gene therapy performed before significant brain involvement can be life-saving.