Causes of flat head syndrome

Many babies are affected by the condition flat head syndrome, or plagiocephaly. Here’s a guide to the causes and how you can get help if it happens to your little one…


“Phoebe had a totally straightforward delivery with no trauma at all, but when she was about 3 months old, I began to think her head wasn’t quite the right shape,” says Jen Doubtfire, 24, from Scarborough, mum to Phoebe, now 17 months. “Instead of it being round it was like an egg laid on its side, completely flat at the back and she had a large forehead. The moment I realised, I instantly felt guilty, wondering whether it was something I’d done wrong.”


Jen was told by her GP that Phoebe had plagiocephaly, or flat head syndrome – 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.

What causes it?

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 ad equately. 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.

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.

Spotting the signs

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.”

Getting help

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 and there are plenty of things you can do in the meantime to help your baby. A good start for more help and advice would

How you can help

“Avoid prolonged car seat use as hard materials will press on the head,” advises Rachel. “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, too. Although it’s definitely not recommended that babies sleep on their fronts, it’s perfectly OK for you to put them on their tums for playtime.

“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,” says Rachel.

Make sure if you’re breastfeeding to swap sides regularly so your baby gets used to using different muscles. And once your baby’s in his cot, you can try using a rolled-up towel under the mattress, which will help your child sleep with less pressure on the flattest part of his head. 

Mum’s story

“My husband and I were watching TV when he casually asked, ‘Do you think there’s something wrong with Austin’s head?’ I’d been worried for a couple of weeks but hadn’t wanted to think about it – I just hoped it’d go away. But the minute my husband said it my stomach fell through the floor. I then felt so guilty that I hadn’t said anything sooner.

We went straight to the GP and my feelings turned to anger and frustration, as we were told it could get better on its own and once his hair grew we wouldn’t notice it as much. For me, this wasn’t good enough and by now one side of his head was really flat. His forehead was protruding, so one eye and cheek were a bit more forward, and one cheek was also slightly fuller. We tried everything from physio, and re-positioning (which helped with the torticolis but not with his head shape), to pillows and osteopathy. I was devastated.

I’d seen a baby in a helmet at our baby class and, after speaking to his mum, decided to get one. We went to Ossur (, where Austin’s head was scanned, measured and a helmet made to fit. I was worried he wouldn’t like it but you build up slowly. Austin had to wear it for 23 hours a day, and I felt really guilty, but he didn’t mind wearing it at all. It’s been arou nd six months now and he’s fine, his head looks normal and we’re much happier.”


Kate Attmere, 33, from Kent, mum to Austin, 15 months


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