Baby Fontanelle: Soft Spot Normal vs Worrying | Parenting Hub
The soft spot on baby's head is normal and protected by tough membrane. Learn when bulging or sunken fontanelle is urgent.
The soft spot is protected by strong membrane — safe to touch and wash. Bulging or sunken fontanelle is urgent.
What it is
Babies are born with gaps between the skull bones (fontanelles) covered by tough membrane. The diamond-shaped one at the top (anterior fontanelle) closes between 9 and 18 months. The smaller one at the back closes by 2–3 months.
Fontanelles let the head mould during birth and allow rapid brain growth in the first year.
What's normal
- Soft and flat when baby is calm and upright
- Slight pulsing visible (baby's heartbeat) — normal
- Slight bulge briefly when baby cries or strains — normal
- Safe to touch, wash and brush over
Bulging fontanelle — urgent
A fontanelle that's firm, raised, and tense even when baby is calm and upright can signal raised pressure in the brain — from infection (meningitis), bleeding or fluid build-up. Always urgent.
Sunken fontanelle — urgent
A clearly sunken fontanelle suggests significant dehydration, especially alongside fewer wet nappies, dry mouth and lethargy. Same-day medical assessment.
When to see a doctor
Routine check if fontanelle hasn't closed by 18 months, or has closed before 6 months. Otherwise it's checked at all MCH nurse visits.
When to seek help
- Bulging, tense fontanelle when calm and upright
- Clearly sunken fontanelle
- Fever, vomiting or unusual sleepiness with bulging fontanelle
- Fontanelle closing before 6 months or open after 18 months
Common questions
Can I hurt my baby touching the soft spot?
No. The membrane is strong and protects the brain. You can wash and brush over it gently.
Why does it pulse?
You're seeing baby's pulse through the soft membrane. It's normal and harmless.