Flat Head in Babies (Plagiocephaly): Causes & Treatment | Parenting H…
Flat spots on baby's head from back-sleeping are common and usually self-correct. Learn prevention, tummy time and when a helmet helps.
Flat spots from safe back-sleeping are common and almost always cosmetic. Tummy time, varied positioning and time fix most without a helmet.
Why it happens
Baby skulls are soft and shape with pressure. Safe back-sleeping (which prevents SIDS) puts steady pressure on the back of the head. This can cause a flat spot — most often on one side (plagiocephaly) or across the back (brachycephaly).
Back-sleeping is non-negotiable for SIDS prevention. The fix is positioning and tummy time, not changing sleep position.
Prevention and treatment
These are the same — start as early as you can.
- Supervised tummy time from day 1 — short sessions, building up
- Alternate which end of the cot baby's head is at each sleep
- Carry baby in different positions and arms
- Limit time in car seats, bouncers and prams when not travelling
- Lots of upright cuddles and floor play
Torticollis (tight neck)
If baby prefers to look one way and resists turning, they may have torticollis — tight neck muscles often paired with flat head. Physiotherapy from a children's physio is very effective if started early.
Helmet therapy
Helmets are rarely needed. They're considered for moderate-to-severe flat spots not improving by 4–6 months, fitted by a specialist and worn 23 hours a day for several months. Most Australian guidelines recommend positioning first, helmet only if severe.
When to see a doctor
See your GP or MCH nurse if the flat spot is getting worse, baby has a strong head turn preference, or the head shape looks very uneven by 4 months.
When it's not just flat head
Very rarely, the skull plates fuse too early (craniosynostosis) — the head shape is ridged or pointed rather than flat. This needs paediatric review.
When to seek help
- Flat spot getting worse despite positioning
- Strong neck-turn preference (possible torticollis)
- Ridged or pointed head shape (not flat)
- Asymmetric face or ear position
Common questions
Will it go away on its own?
Most flat spots improve markedly by 12–18 months as baby spends more time upright. By school age, hair usually covers any remaining flatness.
Can I let baby sleep on their side or tummy?
No. Back-sleeping prevents SIDS and is non-negotiable. Manage flat spots with positioning, tummy time and varied carrying — not sleep position.