It’s common for a newborn's head to have an unusual shape shortly after birth, often due to pressure during delivery. In most cases, this temporary misshaping corrects itself within the first few weeks of life. However, some infants may develop a flat spot on the back or one side of the head in the months that follow—a condition often referred to as positional plagiocephaly.

What Causes Flat Spots on a Baby’s Head?

An infant’s skull is made up of soft, flexible bones that allow for rapid brain growth. These bones can shift or flatten when pressure is applied consistently to one area. Some common risk factors include:

• Spending long periods lying in one position

• Being born prematurely (preemies often have softer skulls)

• Limited head movement due to neck tightness or a condition known as torticollis

• Prolonged time spent in car seats, swings, or other reclined devices

Flat spots can form when a baby lies on their back without repositioning. It’s important to note that sleeping on the back remains the safest position to reduce the risk of Sudden Infant Death Syndrome (SIDS). However, while infants must sleep on their backs, awake time should be used to reposition and vary the baby’s head position.

How to Prevent Flat Head Syndrome

While some degree of head flattening is normal, there are several things caregivers can do to reduce the chances of it becoming noticeable or severe:

• Back to sleep, tummy to play: Always place your baby on their back to sleep, but give them supervised tummy time throughout the day while awake. This strengthens neck and shoulder muscles and relieves pressure from the back of the head.

• Alternate head positions: Slightly change the direction your baby faces in the crib each night. Babies tend to look toward the room or light source, so alternating head positions encourages even pressure distribution.

• Limit time in baby gear: Reduce extended use of carriers, bouncers, and swings when not necessary. These devices often keep the baby in a reclined position with the back of the head in contact with a firm surface.

• Hold your baby often: Carrying your baby upright not only fosters bonding but also minimizes the time their head rests against flat surfaces.

• Encourage head movement: If your baby shows a preference for looking in one direction, try placing toys or talking from the opposite side to help them turn their head.

Making Tummy Time More Enjoyable

Tummy time is essential for development, but not all babies take to it immediately. Here are some tips to help make it a more engaging and effective experience:

• Place a colorful toy just out of reach to encourage reaching and lifting the head.

• Create a circle of soft toys to promote movement in multiple directions.

• Lie on your back with your baby on your chest, which often motivates them to lift their head and look at you.

• Involve siblings or other family members in gentle, supervised tummy play.

When to Seek Medical Guidance

Your pediatrician will check your baby’s head shape during regular visits. If a flat area develops or persists, the doctor may examine the skull’s soft spots and suture lines and take head measurements. A specialist may also use scanning tools to assess the shape and determine the severity of the condition.

For most infants, repositioning techniques and tummy time lead to gradual improvement. However, if these methods are not effective—particularly in moderate to severe cases—a cranial helmet may be recommended.

Helmet Therapy: What to Expect

Helmet therapy involves wearing a lightweight helmet with a soft inner lining that applies gentle pressure to reshape the head over time. The device is custom-fitted and adjusted as the baby grows. Treatment typically lasts between three to six months, depending on the child’s age and the degree of flattening.

The best results are usually seen when therapy begins before the baby is one year old, as the skull is most malleable during early infancy.

What Is Craniosynostosis?

Sometimes, an abnormal head shape may be caused by a condition called craniosynostosis, in which one or more of the skull bones fuse too early. This is different from positional plagiocephaly and usually requires surgical intervention. A specialist, such as a pediatric neurosurgeon, can determine whether the skull shape is due to early fusion or external pressure.

Final Thoughts

Flat spots on a baby’s head can be concerning for parents, but in many cases, they can be corrected with simple changes to positioning and daily routines. Early attention and regular pediatric evaluations help ensure proper development. If you're ever unsure about your baby’s head shape or positioning, consult with your child’s healthcare provider for guidance tailored to your baby's individual needs.