When a baby spends a lot of time in one position, it can cause the shape of their head to change. This is called a positional skull deformity.

For about 20% of babies, a positional skull deformity occurs when they are in the womb or in the birth canal. More often, it happens in the first 4 to 12 weeks of life. This is when babies are not able to sit up or move on their own. By 6 months of age, many babies become more mobile and can turn their heads on their own more regularly.

What Causes a Baby’s Head Shape to Change?

A baby’s skull has soft, bony plates that haven’t yet fused together. The bony plates can move a bit, which helps the baby’s head to pass through the birth canal. The plates also allow room for the brain to grow during the first year of life.

There are many things that can cause a positional skull deformity, such as:

• Preferred head position. Some babies like sitting or sleeping with their heads turned a certain way.
• Not enough tummy time. Tummy time is for babies who are awake and being watched. It helps babies master basic milestones like head lifting, turning over, sitting up, and crawling.
• Twin or triplet. Cramped or unusual positions in the womb can lead to changes in head shape.
• Prematurity. Lying flat on their backs in the hospital can cause a preemie’s head to become misshapen. Preemies also have softer bones that are not as fully formed as the bones of full-term babies.
• Birth complications. The baby’s position when moving through the birth canal can affect his or her head shape. Some other things that affect a baby’s head shape at birth are using forceps, vacuum extraction, or even a difficult labor.
• Torticollis. An estimated 85% of babies with torticollis, a condition where the neck muscles are tight or imbalanced, have a positional skull deformity. Infants who have torticollis also will need physical therapy.

Three Common Misshapen Head Types

A baby’s head shape change usually is related to the position in which they spend the most time. Your pediatrician can determine whether your baby’s head shape is caused by a positional skull deformity or an uncommon but more serious condition called craniosynostosis. Common positional skull deformities do not require surgery.

Note: A good time to check your baby’s head is after bath time when his or her hair is wet.

• The back of your baby’s head should be evenly round.
• Your baby’s ears should be even.
• The width of your baby’s head and forehead should be even and balanced.

If you notice any changes or have any concerns, talk to your pediatrician.

What if My Baby has a Positional Skull Deformity?

The best treatment is to prevent a positional skull deformity. And when it is found early, simple changes to your baby’s position will help. For example:

• Avoid too much time in a car seat, bouncy seat, baby swing, or other carrier. These positions put pressure on the back of your baby’s head.
• Increase tummy time. It is important to put babies on their backs to sleep. But a baby needs supervised time on their tummy to play during the day. This also lets your baby exercise their neck, back, shoulders, arms and hips. Start with short spurts of time. Gradually work up to an hour per day in several short sessions.
• Switch or alternate arms when holding and feeding your baby.
• Alternate which end you of the crib you place your baby down for sleep.

Positional skull deformities do not affect brain growth or intellectual development. They are purely cosmetic, and the majority do not require surgery.

Early Intervention and Therapy

In some cases, your baby’s doctor may recommend treatment for positional skull deformity, particularly those with moderate or severe flattening.

Remember

Talk with your pediatrician if you have any questions or concerns about your baby’s growth and development.

Source: American Academy of Pediatrics Section on Neurological Surgery and Section on Plastic Surgery. Adapted from HealthyChildren.org When a Baby’s Head Is Misshapen: Positional Skull Deformities.

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