Quick answer: Positional plagiocephaly — the technical term for a flat spot on a baby’s head — has become significantly more common since the ‘Back to Sleep’ campaign of the 1990s.
Positional plagiocephaly — the technical term for a flat spot on a baby’s head — has become significantly more common since the ‘Back to Sleep’ campaign of the 1990s. It’s almost always treatable with repositioning, and rarely requires anything more than consistent effort.
What Causes Flat Head Syndrome
Baby skulls are remarkably malleable at birth — the bones haven’t fused and can be shaped by sustained pressure. Positional plagiocephaly occurs when a baby consistently lies or rests with their head in the same position, creating a flat spot where pressure is concentrated. The most common cause: always turning the head to the same side (due to a preference for a comfortable head position, torticollis — a tight neck muscle — or simply habit). Risk factors: prolonged time on a flat surface (spending long periods in bouncers, car seats, and on their back without positional variation), premature birth (softer skull), torticollis (neck muscle tightness causing a head-turning preference), and multiple births (less room in the womb).
Prevention: Starting From Day One
- Alternate head position for back sleeping — place baby’s head at the opposite end of the cot on alternate nights so they look toward the room from different sides
- Tummy time from day one — at least 30 minutes daily total from 2 months
- Carry baby upright in a carrier — takes pressure off the back of the head
- Limit time in bouncers, car seats, and swings — these all encourage the same head position
- Position yourself on alternating sides for feeds and interaction to encourage head turning both ways
- If baby consistently turns to one side, consider physiotherapy to assess for torticollis
How It’s Treated
Repositioning (first-line, 4–7 months): Consciously reversing the preferred head position through the measures above. Most mild-moderate plagiocephaly responds well to repositioning if started before 4 months. Continue tummy time aggressively, alternate sleeping positions, and limit flat-surface time. Physiotherapy (if torticollis present): If neck muscle tightness is preventing the baby from turning freely, physiotherapy stretches treat the underlying cause. Assessment by a paediatric physiotherapist is worthwhile if baby consistently favours one side. Helmet therapy (for severe cases, 4–12 months): Custom-moulded helmets (cranial orthoses) are worn 23 hours per day for 2–4 months, using the helmet’s shape to redirect skull growth. Effective for severe cases identified before 12 months. After 12 months, skull growth slows and helmet therapy is less effective.
When to Refer
See your health visitor or GP if: the flat spot is visibly significant from above (head looks asymmetrical when viewed from above), one ear is positioned further forward than the other, there’s an obvious forehead bulge, or baby consistently turns to one side. Early assessment gives the best chance of non-surgical correction.
Frequently Asked Questions
Does flat head syndrome affect the brain?
Positional plagiocephaly is a skull shape issue only — it does not affect the brain, intelligence, or development. The brain shapes the skull, not the other way around. While the flat spot looks concerning, it has no neurological implications.
Will the flat spot self-correct as baby grows?
Mild flat spots often improve significantly as babies become more mobile (rolling, sitting, crawling) from 4–6 months onward — reduced time on a flat surface, increased head position variety, and ongoing skull growth all help. Severe flat spots without treatment are less likely to fully self-correct.
Is helmet therapy worth it?
Evidence for helmet therapy effectiveness is moderate — multiple studies show improvement over repositioning alone for severe cases, particularly when started between 4–8 months. Whether the degree of improvement justifies the cost (helmets are not routinely NHS-funded in the UK; US coverage varies) and the practicality of wearing a helmet 23 hours per day is a family decision. Discuss with a specialist.
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Related Reading
- 1 month old baby: milestones, sleep & feeding guide
- Tummy time: how to do it, when to start and why it matters
- Safe sleep for newborns: the complete ABCs guide
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