Quick Answer
Seeing your baby's soft spot (fontanelle) visibly pulsing can be startling, but it is completely normal. The pulsing you see is simply your baby's heartbeat being transmitted through the blood vessels beneath the thin skin of the fontanelle. It is a sign of healthy circulation, not a cause for concern.
Why It Happens
The fontanelle — commonly called the soft spot — is a gap between the skull bones that allows the baby's head to flex during birth and gives the rapidly growing brain room to expand in the months after. There are two fontanelles:
- Anterior fontanelle: The larger soft spot at the top of the head, typically diamond-shaped. This is the one most parents notice pulsing. It usually closes between 12 and 18 months of age.
- Posterior fontanelle: A smaller soft spot at the back of the head. This one closes much earlier, usually by six to eight weeks after birth.
Because the fontanelle is covered only by a thin layer of skin and connective tissue — not bone — the pulsation of blood through the underlying arteries is visible to the naked eye. This is especially noticeable when:
- The baby is calm and still, making the pulse easier to see
- The baby has just fed or is slightly warm, increasing blood flow
- You are looking at the baby in good lighting at the right angle
The pulsing typically matches your baby's heart rate, which in newborns is normally between 100 and 160 beats per minute — much faster than an adult's, which is why it can look quite pronounced.
What Parents Can Try
- No action is needed — a pulsing fontanelle is a normal, healthy sign
- Handle the soft spot gently during bathing, hair washing, and everyday care — it is more resilient than it looks but still deserves care
- Avoid pressing on the fontanelle
- Use the fontanelle as a useful health indicator — its appearance can give you clues about your baby's wellbeing (see below)
What the Fontanelle Can Tell You
Beyond the normal pulse, the fontanelle's appearance can be a helpful health signal:
- Slightly sunken: Can be normal, but if noticeably sunken alongside reduced wet nappies, dry mouth, or lethargy, it may indicate dehydration — contact your pediatrician.
- Bulging when calm and upright: A fontanelle that bulges when the baby is not crying and is held upright can indicate increased pressure inside the skull and warrants prompt medical attention.
- Normal at rest: The fontanelle may bulge slightly when a baby cries, strains, or coughs — this is normal and not a concern.
When It’s Worth Checking In With Your Pediatrician
Contact your pediatrician promptly if you notice:
- A fontanelle that is persistently bulging when your baby is calm and held upright — not just during crying
- A fontanelle that appears very sunken alongside signs of dehydration such as fewer wet nappies, no tears when crying, or a dry mouth
- The fontanelle closes very early (before six months) or seems to be hardening, which can occasionally indicate premature skull fusion
- The fontanelle has not closed by 18 to 24 months of age
- You notice any swelling, redness, or warmth around the fontanelle area
Key Takeaway
A pulsing soft spot is one of those things that looks alarming but is completely normal — it simply means your baby has a healthy heartbeat and good circulation. The fontanelle is one of the most useful windows into your newborn's health, and learning what normal looks like will help you feel more confident in the weeks and months ahead.
Parents Also Ask
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This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your pediatrician or a qualified healthcare provider with questions about your baby’s health.