What is flat head syndrome? Spotting the signs

Flat head syndrome, or plagiocephaly. We explore the causes and how you can get help if it happens to your baby


Plagiocephaly, or flat head syndrome, is a flattening of the head caused by external pressure.  


A surprisingly common condition that affects 16 in every 1,000 babies. Symptoms vary, but can include a flatter part at the back or the side of the head, misaligned ears, a bulging forehead, or one eye seeming bigger than the other.

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 infancy.

Spotting the signs of flat head syndrome

The best way to check your baby’s skull is from above. If your baby has plagiocephaly, the 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.”


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?

In recent years, growing awareness about SIDS (sudden infant death syndrome) has led doctors to recommend that babies sleep on their backs. Some people argue that this has caused a rise in cases of flat head syndrome, but 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 he 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 Rachel. “You should be able to tell whether your baby’s head is OK at around 2 months of age. Before then it 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. Your child might be referred to a physiotherapist who will begin stretching exercises and massage, but getting an appointment can take some time.

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 she seems to prefer to hold her head on one side
  • Change the way your baby lies in her cot each week, this encourages your baby to look around, rather then keep her 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. Increase tummy time
  • Cuddle!
  • Don’t be tempted to let your baby stay too long in her bouncer or car seat as this can encourage other growth and development problems and prolonged car seat use as hard materials will press on the head
  • Don’t panic! Repositioning should be the initial treatment and very often the problem goes away on its own. If you’re concerned, speak to your GP
  • If your baby’s flat head is severe, the Trust recommends seeking advice from a health professional

Read more on flat head syndrome and safe sleeping…


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