The correct name for a flat or misshapen head is plagiocephaly. Babies are often born with a misshapen or asymmetrical head because of the way they were lying in the uterus, or because of pressure during birth. After they’re born, the skull bones can change shape easily and develop a flat spot, especially if babies lie in the same position for a long time. This is called ‘positional plagiocephaly’.
Why is my baby’s head flat?
Very young babies have skull bones which are soft, flexible and thin. For some months after birth, these bones are still soft enough to be moulded, especially if there is continual pressure in one area.
It can help to think of their skull as soft plates with spaces in-between. As the baby grows, these plates also grow, becoming harder and knitting together.
Some babies also have tight neck muscles which means they can’t move their head equally to both sides. They tend to develop a preference for turning their head to one side and then lying and sleeping on the same side most of the time. These babies are more likely to have flattening on one side, rather than on the back of their head.
Plagiocephaly is also common because of the position babies sleep in. Back sleeping is recommended as the safest position, as per Red Nose guidelines. Because babies can spend many hours on their back each day (and night), this creates pressure to build up in the same spot. Lying awake in their bassinet or cot, pram, bouncer and car seat all mean the baby rests their weight on the same spot during wakeful times as well as when they’re sleeping.
Babies who prefer to lie in the same position can also develop a bald spot on their head. This can mean the flat spot is more obvious, especially if the rest of their hair is dark.
How can I prevent my baby getting a flat spot?
Plagiocephaly is preventable for most babies. Avoiding continual pressure on the same spot is helped by alternating the baby’s head position (left or right) when they are sleeping. This is called ‘counter positioning’. Tummy time when the baby is awake and being supervised also helps. This also supports upper body strength and progress in building rolling skills.
Avoid your baby sitting in the same position for long periods of time. It can also help to change the baby’s feeding position by alternating which arm you hold them for feeds. This happens automatically when breastfeeding, but it’s also worth doing for babies who are bottle fed.
Will having a flat head affect my baby’s brain?
There is no evidence to support the theory that plagiocephaly affects brain development. Sometimes, babies with really significant head flattening need a special helmet fitted which helps to reshape the skull by taking pressure off the flat area. This allows the baby’s skull to grow into the space provided.
When does a flat head go away?
By around the age of six weeks after birth, most babies develop a normally shaped head. This is helped by them building tone and strength in their neck muscles so they can turn their head evenly.
Babies can have varying degrees of plagiocephaly, sometimes it’s less obvious and is not picked up until a health professional checks the baby’s head and is measuring their head circumference.
What is the treatment for a flat head?
Most babies don’t need any special treatment, other than parents making small changes in the way their baby lies and sleeps. As babies spend less time on their back and more time on their tummy or sitting upright, there’s less pressure on their head. In the meantime, the key is to relieve pressure on the same spot during the baby’s sleep and wake times.
5 tips to help manage your baby’s flat head
- Hold your baby at different angles, so they’re looking outwards and can move their head freely.
- Change the position of your baby’s cot in their room so they’re not always looking in the same direction.
- Offer lots of opportunity for tummy time when they’re awake and being supervised.
- Using toys and your voice to get your baby’s attention so they move their head and neck.
- Gently reposition your baby’s head so they’re not lying on the flat spot when they’re awake.
Check with your GP, Paediatrician or Child Health Nurse if you want more information about your baby’s head shape.
Written for Infacol by Jane Barry, Midwife and Child Health Nurse, November 2023.
