Flat Head in Babies

When to get help

Most flat heads need reassurance rather than urgency, but arrange an appointment — GP or health visitor in the UK, GP or public health nurse in Ireland, paediatrician in the US or Canada, GP or child health nurse in Australia and New Zealand — if any of these apply:

• Your baby always turns their head to the same side and resists being turned the other way, or holds their head tilted. This suggests torticollis, a tightness in the neck muscles, and it usually needs physiotherapy.
• You can feel a hard ridge along a line on the skull, or the head shape is unusual in a way that is getting worse rather than better.
• The flattening is getting more pronounced after about six months, when most babies are moving enough for it to improve.
• Your baby's head circumference is not following its expected line on the growth chart.
• There are other concerns: not meeting milestones, a bulging soft spot, or eyes that do not seem aligned.

Call emergency services if a flattening or change in head shape follows a head injury and your baby is drowsy, vomiting repeatedly, or has a bulging soft spot.

Why it happens

A baby's skull is soft and grows fast, which is what lets the brain grow. Sustained pressure on one part flattens it. Babies sleep on their backs, which is the single most important thing you can do to reduce the risk of sudden infant death, and a proportion of them develop some flattening as a result. That trade-off is well understood and it is not a reason to change sleep position.

Flattening across the back of the head is called brachycephaly; flattening on one side, often with the ear pushed slightly forward on that side, is plagiocephaly. It is more common in babies born prematurely, in twins, in babies with a limited range of neck movement, and in babies who spend long stretches in car seats, bouncers and swings.

What actually helps

The principle is simple: reduce the time the flat area spends taking the weight of the head, without changing sleep position.

Alternate which end of the cot you lay your baby down at, so that the interesting side of the room — the door, the window, you — encourages them to turn their head the other way. Move the cot, or the mobile, for the same reason. Change the arm you carry and feed on, and alternate sides during bottle feeds.

Increase supervised tummy time while your baby is awake, in short frequent bursts. Start with a minute or two at a time and build up. On your chest counts. So does lying across your lap.

Limit time in car seats, bouncers, swings and prop-up seats to what is genuinely needed. A car seat is for the car; using it as a daytime resting place adds hours of pressure on the same spot, and prolonged sitting in a car seat is not recommended for sleep in any case.

What you must not do is change sleep position or use a shaped pillow, sleep positioner or wedge. The Lullaby Trust is unambiguous that babies should be placed on their backs for every sleep and that the cot should be clear. No pillow marketed for flat head is safe for a sleeping baby under one.

Helmets

Corrective helmets and headbands are widely marketed and are the single most common question parents ask. The NHS position is that they are not routinely recommended, because there is not good evidence they work better than the head shape improving on its own, and they can cause problems including skin irritation and discomfort. They are also expensive and require a lot of wearing time.

Great Ormond Street Hospital and the American Academy of Pediatrics both frame positional flattening as something that generally improves with repositioning and time. Helmet therapy is used in some services for selected severe cases within a specific age window, and that is a decision to take with a specialist who has examined your baby, not with a company selling the device.

If you do see a private clinic, ask directly what they expect would happen without a helmet, and ask for that in writing.

What the timeline usually looks like

Flattening tends to be most noticeable between about two and four months, when a baby is spending most of their time lying down and the skull is at its softest. It generally starts to improve once they begin rolling, sitting and taking their own weight off the back of the head, and hair growth makes what remains far less visible.

Photograph the head from directly above every few weeks, in the same light, with your baby in a similar position. That top-down view is what clinicians use, and comparing photographs is much more reliable than day-to-day impressions.

Torticollis, the thing behind many flat heads

If a baby cannot comfortably turn their head both ways, they will always rest on the same spot, and repositioning advice will not work until the neck does. Signs include a strong preference for one direction, a head tilt to one side, difficulty feeding on one side, and sometimes a small firm lump in the neck muscle.

The treatment is physiotherapy with stretches you carry on at home, and it works well, particularly when started early. Ask for a referral rather than waiting for it to sort itself out, because the head shape follows the neck.

The shapes that are not positional

Rarely, an unusual head shape is caused by craniosynostosis, where the joints between the skull bones fuse too early. The clues are a hard ridge along a suture line, a head shape that is worsening rather than improving, and a shape that does not fit the positional patterns. Head shape and head circumference are checked at the newborn physical examination and again at routine reviews, which is where most of these are picked up.