lying down baby

This article looks at ‘flat head syndrome’ outlining symptoms, possible causes and treatment.

Flat head syndrome is the name given to the condition when part of a baby’s head becomes flattened due to continued pressure on one spot. There are two types of flat head syndromes in babies.

  • Plagiocephaly - This is a flattening on one side of a baby’s head. Its most common form is ‘positional plagiocephaly’, which happens when a baby’s head develops a flat area due to continued pressure on one side of their head. Babies are most vulnerable because their skull is soft and pliable when they’re born.
  • Brachycephaly - This refers to the condition where a baby’s head is disproportionately wide compared to its depth. It can happen when babies lie for long periods on their backs. This causes the whole of the back of their head to flatten, resulting in a much wider and shorter head. Brachycephaly is less common.

"Surveys show the proportion of babies affected by positional plagiocephaly ranges from 16% at six weeks, 20% at four months7% at 12 months to 3% at 24 months".

Why are some babies affected?

Babies’ skulls are made up of several plates of bone which are loosely held together. As they grow older the bones will gradually join. However, during birth and for the first few months their skulls are very soft and their shape can be changed by gentle pressure. In some babies continued pressure on one area of the skull may lead to some form of flat head syndrome.


  • Flat area on back or one side of the head.
  • Bulging on one side of the head.
  • One ear more forward than the other.
  • Unbalanced look to the face.

Possible causes

It is thought that  there has been an increase in babies with flat head syndrome following the successful ‘Back to sleep’ campaign, which advises laying babies on their backs to sleep. Research studies do not bear this out but there is certainly more awareness of the condition.

The number of babies who have died due to Sudden Infant Death Syndrome(SIDS) has halved as a result of this campaign. However, laying babies on their back to sleep, combined with the use of baby equipment which has babies leaning back onto their heads for periods of time, such as car seats and bouncers, can lead to babies spending more time on their backs than ever before. It must be stressed that the benefits of laying your baby on his back to sleep far outweigh the risks of flat head syndrome (see articles on 'Your baby's sleep').

"Babies who have their head turned one way most of the time, perhaps because of an uncomfortable neck are more likely to develop a flattened head".

Other possible causes could include:


  • Sometimes a baby’s skull may be moulded whilst in the womb. There may not be enough amniotic fluid to cushion the baby, which means his head can become temporarily deformed as he travels down the birth canal. Also, this can happen as part of a multiple birth as the babies become squashed within the womb. This sort of moulding tends to correct itself without treatment.
  • Premature babies are more likely to have an unusual head shape at first because their skulls are less developed. 
  • Muscular problems – sometimes a baby will have tightened muscles in their neck (torticollis), which prevents them from turning their head one way and means they will always rest their head on the other side, causing this to flatten. 
  • Craniosynostosis – rarely a flattened skull can come about by the bone plates within the baby’s skull joining together too soon. This can pull the baby’s head out of shape and will need to be corrected with surgery, so its worth checking with your GP if you are concerned about the shape of your baby’s head.

Are some babies more at risk than others?

This condition shows up most often in babies who:

  • are first born
  • have unusually large heads
  • are premature, twins or multiple births
  • have had an assisted birth (forceps or ventouse)
  • have limited ability to turn their head or torticollis (tight or shortened muscle on one side of the neck, causing the chin to tilt to the other side).

There are other factors which are open to change including:

  • Caring for the baby on one side all the time
  • Not enough  ‘tummy time’ or carrying where there is no pressure on the head
  • Baby’s preference for turning their head to one side.

What can be done to help?

Doctors recommend that your baby is not left on his back for too long or too often, as this can create pressure on the same areas of his head.

Suggestions for reducing pressure on your baby’s head

When asleep:

  • Always put your baby on his back to sleep. If he’s in a cot alternate different ends of the cot to encourage him to sleep on a different side of his head each night or turn the cot around if its against the wall.
  • Move the light in the room as babies tend to follow the source of light.
  • Change the position of his head away from the flattened side when he is sleeping.

When playing:

  • Put your baby down while he is awake, on his front, on a firm, flat surface. This will also help with his  development and co-ordination, strengthening his neck and trunk muscles.
  • Alternate the side you hold him when feeding and carrying.

When travelling:

  • Reduce the time spent with his head on a firm flat surface, such as car seats and buggies.
  • Rather than walk with him in his car seat, take him out and put him in a sling or front carrier.


In most babies, the shape of the head will correct itself by their first birthday. Mild flattening of the skull will normally correct itself by the end of the first year or possibly two. However, this can be helped with a few simple measures to remove pressure on the affected area of the skull. These measures could include:

  • Changing the position of your baby’s head throughout the day so that the rounded side of his head is placed against the mattress, repositioning cribs and other areas that he spends time in so that he will have to look in a different direction to see you  or others in the room.
  • If your baby appears to have discomfort or cries when they are repositioned, they may have a problem with their neck which you can discuss with your health visitor or GP. 
  • For babies older than about five months, some people recommend the use of ‘helmets’ or ’headbands’, known as cranial orthoses to encourage the bones to mould into a more rounded shape. This is somewhat controversial as it is unclear how important head shape is and most babies’ heads would revert to a more rounded shape naturally. These custom-made devices are designed to be used for babies between six and 12 months (during the period of greatest skull growth), to apply pressure to ‘bulgy’ parts of the skull and relieve pressure from other parts. Medical opinion is divided, about the effectiveness of such helmets or whether they are even necessary, believing that the condition generally corrects itself in time.

The Canadian Paediatric Society found that using a specially fitted helmet to reduce the skull flattening ‘has some drawbacks: it is expensive, significantly inconvenient due to the long hours of use per day and associated with skin complications. There is evidence that helmet therapy may increase the initial rate of improvement of asymmetry, but there is no evidence that it improves the final outcome for babies with moderate or severe plagiocephaly.’

The reality

It’s normal for a baby’s head to be slightly misshapen when they’re born, usually as a result of its passage down the birth canal. However, if after a few weeks it does not appear to have improved and/or you notice a flat spot or flattening area on your baby’s head then do take him to see your GP.

A baby’s skull toughens as they grow, so the sooner the condition can be dealt with the more successful the treatment is likely to be. Most conditions will improve over time. Whilst the more severe cases of head flattening may also improve, some flattening will remain. However, in most cases, once baby’s hair begins to grow it won’t be noticeable anyway.

This page was last reviewed in March 2018.

Further information

Our support line offers practical and emotional support with feeding your baby and general enquiries for parents, members and volunteers: 0300 330 0700.

You might find attending one of NCT's Early Days groups helpful as they give you the opportunity to explore different approaches to important parenting issues with a qualified group leader and other new parents in your area.

NCT position statement on Plagiocephaly.

Make friends with other parents-to-be and new parents in your local area for support and friendship by seeing what NCT activities are happening nearby. Link to website branch info
NHS Choices has information on plagiocephaly and brachycephaly.

Headstart4babies belives the use of helmets is useful in treating this condition and provides information to that effect.

The Canadian Paediatric Society Practice as information on Positional plagiocephaly and research on the use of helmets.

Related articles

lying down baby

Local activities and meetups

NCT antenatal film
Why choose an NCT antenatal course?

Courses & workshops

Baby First Aid

Find out more

Early Days

Find out more

Introducing solid foods

Find out more