Babies And Their Head Shapes And Other Info

Here's a description of the changes that take place with regard to your baby's head.
Cara Familian Natterson, MD

Head shape
In order for a baby to be able to travel through the birth canal, the head must be small enough and flexible enough to fit.

Fortunately the brain is only a fraction of its adult size at birth. The bones that surround it are also able to mold into different positions. This explains why most babies that have been resting low in their mother's pelvis, waiting for delivery, have long pointy heads just after birth.

While the head must be extremely moldable, it must also be very sturdy. The skull is responsible for protecting the brain beneath it. It must be strong enough to endure bumps and bonks during delivery and thereafter.

And, in order to grow and develop complex language and thought, the brain and its surrounding skull must be able to expand.

Therefore both the brain and its protective shell are designed to change shape and grow over time. For something so hard to the touch, the bony skull is amazingly malleable.

Head growth is greatest in the first year of life. As the skull grows, it changes shape. Therefore, when a baby is placed in various positions over and over again, the pressure on one particular part of the skull can cause flattening of that area.

While children and adults have relatively fixed head shapes, babies do not. The range of skull shapes and the speed at which the skull changes shape are remarkable.


What is happening inside my baby's body?
The bones that make up your baby's skull are designed to move around so that the head can pass through a tight space when the baby is born. In fact the skull bones look like big pieces of a puzzle: they fit together, but they are not firmly attached.

When a baby hangs upside down and low in her mom's pelvis for days (or weeks), the bones of her skull mold to fit the mom's pelvis. This is why many newborn babies have pointed heads -- a phenomenon called molding. This is a good strategy for a delivering baby because it may help her to pass through a very narrow birth canal.

Some babies do not hang upside down in the pelvis for long (or at all), so they have perfectly round heads at birth. This is especially true among babies born by cesarean section.

The fact that the bones of a baby's skull can move around allows humans to have rapid brain growth, not just while developing inside the womb but after birth as well. In the first two years of life, the human head grows an average of 40 percent, allowing a newborn to be delivered while her brain is still quite immature. In fact humans are the only species born with brains that are so immature that a baby is entirely dependent upon a parent.

Think of horses -- they are able to walk within hours of birth. Humans cannot even crawl yet. Why does this happen? Because humans are born with immature brains that can ultimately develop a level of sophistication that no other animals have.

Again, this is all thanks to a moldable head and movable skull bones. The only alternative in evolution allowing for massive human brain size and sophistication would have been for moms to have gigantic hips!

Molding lasts only a few days after the baby is born. Remarkably the head rounds itself out quickly once a baby has been delivered. Within a week the head assumes a standard round shape, with a soft spot at the very top toward the front and another, smaller soft spot at the top toward the back.

Soft spots
These spots -- called fontanels -- are simply normal spaces between the bones of the skull. They allow for even more growth of the brain and skull after birth. The fontanel at the back of the head typically closes between two and twelve weeks of life; the one at the top of the head usually closes sometime between six and 18 months of age.

What can I do?
Parents do not need to do anything to resolve molding. The head will usually round itself out. However, in some cases, parts of the skull become flat over time. To avoid this, you should put your baby down to sleep on her back, with the head in slightly different positions throughout the day and night.

Sometimes the head is turned to one side, sometimes to the other, and sometimes it is placed in the middle. This strategy, which allows the head to continue to round itself out, is covered in more detail in the section on plagiocephaly that follows.

When does my doctor need to be involved?
What tests need to be done, and what do the results mean?

Tests are unnecessary in the case of molding because the shaping of the skull in the womb is normal.

What are the treatments?
Head molding does not require treatment; it will resolve itself. However, to avoid future flattening of certain parts of your baby's head, you should rotate her sleep position so that she is not continually resting on one part of her head. This is covered in the section on plagiocephaly that follows.

What are the possible complications?
There are no complications from head molding. It resolves quickly on its own.

Additional resources

(One to nine Months)

What is happening inside my baby's body?
Just as the head was shaped in the womb by mom's pelvis, the head is subject to reshaping after birth too. This is because the plates of the skull are pliable, so positioning of the head can dramatically affect its shape over time.

When babies are laid down to sleep in the same position over and over again, specific spots on the skull receive more pressure just from the weight of the head on that area. If the position of the head is not rotated regularly, then the part that repeatedly bears the weight will flatten. For some babies the flat part is on the back of the skull, but for others it is on one side or the other. Noticeable flattening is called plagiocephaly.

Plagiocephaly can also result from repeated positioning while sitting up. When your baby sits in a car seat, his head flops to one side or the other. Head-and-neck pillows help to keep him supported, but sometimes a baby prefers to turn his head in one particular direction, or the seat is arranged so that he is in the same position each time.

Again, gravity and the weight of the head can put pressure on a specific part of the skull, and this can contribute to flattening of one side of the head.

Babies with torticollis have uneven neck muscles. These babies hold their head cocked to one side. They are more likely to develop plagiocephaly simply because they position their own heads in one direction most of the time.

What can I do?
You can rotate your baby's sleeping position regularly. Your baby should sleep on his back, with his head turned alternately to one side, then the other, and then kept in the middle. He can be slightly propped up on his side using a wedge (triangular-shaped pillow) or a rolled blanket tucked behind him.

Any material used to position a baby should be placed below the shoulders so that, in case he squirms and flips over, there is no chance that the material will block the nose and mouth. If a flat area has begun to form on the skull, then an effort should be made to avoid laying the baby on that side until the skull has rounded out again.

If you notice that your baby prefers to look in one direction and this is contributing to flattening of the head on one side, then try to provide entertainment in the opposite direction. Toys can be placed in the crib in such a way that the baby turns his head to look at them.

In the car, a mirror can be placed on the backseat so that he will turn his head to catch a glimpse of himself. When trying strategies like these, you should remember to put the target objects in a place that entices the baby to look in the opposite direction from his favored glance.

When does my doctor need to be involved?
If you notice an area of flattening on the head, let your doctor know.

What tests need to be done, and what do the results mean?
If a baby has plagiocephaly, then tests are usually not necessary. The treatment will typically be the same regardless of any tests that may be done.

What are the treatments?
Helping your baby to round out his head can be difficult because once he has developed a comfortable flat place to rest his head, you will need to do some maneuvering to get him to sleep or to just hold his head in a different position. If repositioning and placing toys and mirrors have not helped, and if the head flattening has become severe, then a helmet may be used. This is unusual.

Helmets help to round out the head. They are firm, so they place gentle pressure on the parts of the skull that are more rounded and no pressure on the areas that are flat. Over time (usually months), the flattened parts of the head become round.

Helmets are almost never used until a baby is four to six months old -- the head will usually round itself out well before then. Helmets are rarely used after a child is 10 to 12 months old, because the bones of the skull are far less moldable by this point.

What are the possible complications?
The only complication of plagiocephaly is a cosmetic one: a permanently flattened head. This is usually hidden by hair, especially when the flat spot is in the back. But in rare cases, one side of the skull is significantly flatter than the other, and the cosmetic effect can be noticeable. If a person has very thin or sparse hair, then the flat spot is more obvious.

Additional resources

Read part two of this article on the next page!


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