Flat head syndrome in babies: prevention and when to see a doctor

Sep 28, 2026

Zaležana glavica pri dojenčku: preprečevanje in kdaj k pediatru

In short: Flat head syndrome (positional plagiocephaly) is a flattening of part of a baby's head that develops when they spend a long time lying with their head in the same position. It is common, does not affect brain development and usually improves once the baby is more mobile. Tummy time while awake and changing positions help most – but your baby still sleeps on their back, without a pillow.

Author: Eva Birsa, mum and co-founder of Evitas · Updated: 28 Sep 2026

What is flat head syndrome?

A baby's skull is soft in the first months and can change shape slightly under constant pressure. If a baby spends most of the time with their head resting on the same side, that part of the head flattens. Doctors call this positional plagiocephaly (one side of the back of the head is flat and the head looks lopsided from above) or brachycephaly (the back of the head is evenly flattened in the middle).

The NHS stresses that flat head syndrome is common in babies and does not affect the brain or development – it is about head shape. The American Academy of Pediatrics (AAP) adds that the shape often improves on its own once the baby becomes more mobile (around 6 months) and spends less time on their back.

What causes it?

Lying in the same position for long periods – for example, when a baby always turns their head towards the window or door in the cot.
Lots of time in a car seat, swing or bouncer, where the head keeps pressing on the same spot.
Tight neck muscles (torticollis) – the baby finds it harder to turn their head to one side. The AAP estimates that 85% of babies with torticollis also have a positional skull deformity; they need physiotherapy as well.

Safety first: babies sleep on their back – without a pillow

Sleeping on the back is the safest position for babies and reduces the risk of sudden infant death syndrome (SIDS). So don't give it up for fear of a flat head. For every sleep, day and night:

your baby always sleeps on their back,
on a firm, flat mattress that fits the cot snugly,
with nothing else in the cot until 12 months: no pillows, nests, bumpers, toys or positioners.

The Lullaby Trust does not recommend wedges or sleep positioners, and the US FDA warns parents not to use infant positioners because of the risk of suffocation. The AAP states clearly that head-shaping pillows are not safe for sleep. For a safe sleep space, see How to choose a baby cot.

How to prevent flat head syndrome

Tummy time: whenever your baby is awake and you are watching, place them on their tummy. The AAP advises starting on the first day home: 2–3 times a day for 3–5 minutes, working up to 15–30 minutes a day by 7 weeks. A soft play mat makes it easy – see our baby play mat guide for tips.
Alternate ends of the cot: lay your baby (always on their back) at alternate ends of the cot, so they turn their head towards the room on one side one time and the other side the next.
Switch arms when feeding and carrying, and offer toys and talk from both sides.
Limit time in car seats, swings and bouncers – use the car seat for travelling, not for sleeping at home.
More upright time in your arms: while cuddling or carrying your baby in an ergonomic baby carrier, there is no pressure on the back of the head.

Prevention by age (0–6 months)

Age	What to do	What to watch for
0–2 months	Tummy time from day one: 2–3 times a day for 3–5 minutes (also on your chest); alternate sides in the cot and when feeding	Always sleep on the back in an empty cot; check that your baby turns their head equally to both sides
2–4 months	Tummy time 15–30 minutes a day in total (by 7 weeks, per the AAP), toys on both sides, more upright time in your arms	Limit car seat, swing and bouncer time; if the flattening isn't improving or the head is always tilted, see your doctor
4–6 months	Lots of tummy play and free movement on the floor (rolling, crawling)	Once your baby rolls, pressure on the head usually eases; a specialist decides on a helmet in marked cases

Koala Perfect Head pillow: what it is and how to use it

Koala Babycare Perfect Head AIR is a small ergonomic pillow by the Italian brand Koala Babycare with a central indent for the back of the head that spreads the pressure over a larger area. According to the product description:

the core is BASF memory foam (Germany) with a breathable structure, free of formaldehyde, lead and phthalates,
it measures 26 × 23 × 3 cm, is made in Italy and has a 2-year warranty,
it comes with 2 covers (OEKO-TEX® Standard 100) and a storage pouch,
it is available in White and Grey; see the Koala Babycare collection for other products from the brand.

The manufacturer describes it as a Class I medical device with CE marking, accredited by the Italian Ministry of Health (“Medical Device Class 1”, “Accredited by the Italian Ministry of Health”).

Manufacturer's official instructions

Use under adult supervision, not suitable for sleeping.
Up to 6 months, or until your baby can roll over on their own, use it only while your baby is awake and supervised.
Suitable for babies up to 12 months, for example in a pram, bouncer or on a play mat – always supervised.
Place the back of the head in the centre of the indent; the shoulders stay off the pillow.
Do not wash the foam core – wash only the covers.

So the pillow does not replace tummy time and position changes, and it doesn't belong in the cot for sleep. If your baby already has marked flattening or keeps their head tilted, talk to your paediatrician or physiotherapist before using any aid.

When to see a doctor

If you are worried about the shape or size of your baby's head.
If your baby's head is always tilted to one side or they find it hard to turn it (possible torticollis – physiotherapy helps).
If the flattening isn't improving after a few weeks of position changes and tummy time, or is getting worse.
If the head has an unusual shape from birth – your doctor will rule out rare craniosynostosis (early fusion of the skull sutures), which needs different care.

When is a helmet considered?

Most babies don't need a helmet. The AAP says a specialist may recommend one at around 5–6 months if moderate or severe flattening persists despite position changes. The NHS does not provide helmets or headbands because there isn't enough evidence that they work. The decision should always be made by a specialist after an examination.

Frequently asked questions

Is flat head syndrome dangerous?

No. According to the NHS and the AAP, positional plagiocephaly does not affect brain development – it concerns head shape, which often improves as the baby sits, rolls and crawls more.

When should I see a paediatrician?

When you're worried about head shape, when your baby always tilts their head or finds it hard to turn, and when the flattening doesn't improve despite the measures. The doctor also checks for torticollis and rules out craniosynostosis.

Does a pillow help with flat head syndrome?

A pillow such as Koala Perfect Head can spread the pressure on the head while your baby is awake and supervised, but it doesn't replace tummy time and position changes. Use it strictly according to the manufacturer's instructions.

Can my baby sleep on the pillow?

No. Safe sleep guidance (AAP, The Lullaby Trust) says babies up to 12 months should sleep on their back on a firm, flat mattress with no pillow or other items. Koala also states that Perfect Head is not suitable for sleeping.

When is a helmet needed?

Only for moderate or severe flattening that doesn't improve despite the measures – a specialist decides, usually at around 5–6 months.

How much tummy time does a baby need?

The AAP advises starting on the first day home: 2–3 times a day for 3–5 minutes, then gradually more, up to 15–30 minutes a day by 7 weeks – always while your baby is awake and supervised.

Sources

This content is for information only and does not replace advice from your paediatrician.