Plagiocephaly, or flat head syndrome, is a flattening of the head caused by external pressure. It's a surprisingly common condition that affects 16 in every 1,000 babies and has increased following the success of Safe Sleeping Guidelines, which advise that babies are always put to sleep on their back.


When do babies get a flat head?

Flattening of baby's head can start in the womb or during birth, but mostly it occurs after your baby’s born and is common in the first few months.

Spotting the signs of flat head syndrome

The best way to check your baby’s skull is from above. If your baby has plagiocephaly, their skull will look more like a sideways rectangle than an egg.

A baby’s brain and development aren’t usually affected and the condition may correct itself in time. As a result, flat head syndrome is often dismissed by the medical profession as a cosmetic problem.

Nevertheless, it can be distressing for both baby and parents. “Babies with plagiocephaly can be more fretful,” says paediatric physiotherapist Rachel Harrington. “They may find it difficult to feed as they only want to use one side and it may be harder for them to get a comfortable sleep position.”

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What causes flat head syndrome?

Although it’s quite a rare occurrence, plagiocephaly can occur in the womb due to a number of factors, including multiple births (where the babies are squashed together in the womb), premature births (which can result in the bones in the skull not having had time to firm up properly), poor muscle tone, and a condition known as oligohydramnios, which is where insufficient fluid in the uterus fails to cushion the baby adequately.

However, most cases are diagnosed at around 2 months, and often referred to as positional plagiocephaly, where the skull has been altered by external forces, such as a mattress, car seat, or anything that can mould the head.

Is flat head syndrome caused by a baby sleeping on his back?

As mentioned, the increase of babies sleeping on their backs, following a campaign to reduce SIDS (sudden infant death syndrome) has also coincided with a rise in cases of flat head syndrome. However, most would agree that the benefits of the campaign for safe sleep far outweigh problems caused by plagiocephaly.

A flat head syndrome baby can often also suffer from torticolis (tightening of the neck muscles), which means they may favour the same side for sleeping, feeding and so on, because the other side is painful.

Are baby pillows safe?

Health professionals at the NHS and safe sleep experts at the Lullaby Trust say you should not use any pillows (including baby pillows) before your little one's a year old, as they may pose a risk of suffocation.

Getting help for plagiocephaly

As with most medical problems, an early diagnosis is essential. “The younger children start treatment the better. Although we can help babies as old as 2, it’s important to start conditioning exercises as soon as possible,” explains paediatric physiotherapist Rachel. “You should be able to tell whether your baby’s head is OK at around 2 months of age. Before then your baby could still be recovering from the birth.”

Any problems should be picked up by your health visitor or at the first GP check-up, but if you have any worries at all, you should seek medical advice straight away.


Should I use a helmet?

Research carried out by a Dutch study in 2014 suggested that special helmets designed to correct flat-head syndrome actually make no meaningful difference to a baby's head shape.

The helmets – which are often expensive and have to be worn for 23 hours a day over 6 months or more – have become increasingly popular with parents who are concerned that their baby has flat-head syndrome.

But, according to the Dutch study, children who don't wear these helmets are as likely to make a full recovery from flat-head syndrome as those who wear them.

A helmet can cost up to £2,500, and parents in the new Dutch study reported side effects of wearing them that included:

  • Skin irritation (in 96% of cases)
  • Feeling hindered from cuddling baby (77%)
  • Unpleasant smell (76%)
  • Sweating (71%)
  • Pain (33%)

Researchers concluded that they'd "discourage the use of a helmet as a standard treatment for healthy infants with moderate to severe skull deformation". That said, of the parents whose babies wore helmets, the average satisfaction score after the end of treatment, and when the baby was assessed at 2 years old, was 4.6 out of 5.

How do you address flat-head syndrome without a helmet?

If the deformation is mild, your baby's skull should correct itself naturally over time if you:

  • Give your baby time on their tummy during the day and encourage her to try new positions during play time.
  • Switch your baby regularly between a sloping chair, a sling and a flat surface, so that there isn't constant pressure on one part of her head.
  • Change the position of toys and mobiles in her cot to encourage your baby to turn her head to the non-flattened side.

If your baby's deformation seems more severe or they seem to have problems turning their neck in one direction, you should seek medical advice. Your GP may decide they need more intensive treatment, such as physiotherapy to help loosen their neck muscles.

What can I do to prevent flat head syndrome?

  • Limiting your baby’s time on their back when they are awake
  • Lay your baby down in a different way, especially if they seem to prefer to hold their head on one side
  • Change the way your baby lies in their cot each week, this encourages your baby to look around, rather then keep their head in a single position
  • When you’re out and about, alternate between the pram and carrier to change your baby’s position
  • Give your baby plenty of tummy time
  • Babies like to look around them, so it’s a good idea to change things round in the room or place lights so they’re tempted to look in different directions
  • Make sure if you’re breastfeeding to swap sides regularly so your baby gets used to using different muscles.
  • Don’t be tempted to let your baby stay too long in her bouncer or car seat

Mum’s story

“We were horrified at out son’s flat head but repositioning helped”

“I have to be honest, Arnie came into this world as a rather odd-looking baby, all scrunched up. My theory is he was a bit squashed in the womb by his active twin brother!

“But I was horrified at 6 weeks when I brushed his hair back to see the left side of his head was almost completely flat. It was so severe that at 8 weeks, he had a head x-ray and ultrasound to assess his bones and brain. Luckily all was well.

“We relentlessly encouraged him to sleep on his back or on his right side – popping in every half hour in case he’d slipped back to the left (usually he had) – and when he was awake positioning him so he had to turn his head to see what was going on, so he wasn’t ‘locked’ in the left position. The results were amazing and happened incredibly fast. In a month he’d lost his ‘odd’ look and now has a perfectly symmetrical head.”

Jane, 35, mum to Arnie and Sam, 3


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