What Is the Baby’s Soft Spot?

Medically Reviewed by Dan Brennan, MD on April 14, 2023
3 min read

When your baby is born, their skull is very soft. The individual pieces of their skull aren’t fused together yet, allowing them to fit through the birth canal with ease. When your baby is born, you may notice a soft indentation on the top of their head. This is perfectly normal and no cause for concern.

Once your baby is born, you may notice two soft spots on their head. There is one gap at the top-front of the skull that is most noticeable. The other is smaller, toward the back of their head. Depending on your child and the size of these spots, you may not even notice them. 

A baby's soft spots are called fontanelles. They allow your baby’s brain to grow larger at a fast rate over their first year of life. It's important to avoid pressing into their soft spots, as it could cause damage to their skull or brain.

What should the soft spot look like? The soft spot is often noticeable because it may bulge out when your baby cries or pulses up and down with your baby’s heartbeat. When your baby nurses or takes a bottle, you may see the soft spot move along with the motion of their sucking.

When does the soft spot go away? Since the back soft spot is smaller, it usually closes around three months old. The larger spot on the top-front of their skull won’t close until around 18 months old. As your baby ages, you will notice that the spots get smaller and smaller with each passing month until they are barely noticeable.

Your child's doctor may examine the soft spot during regular checkups to make sure the development looks correct for your baby’s age.

Soft spot. If you notice that your baby’s soft spot appears swollen for an extended period of time, that is cause for concern. It could be a sign that your baby’s head is swelling. If your doctor suspects brain swelling, they may request imaging tests and blood work to find out what’s the cause.

Your baby’s soft spot may also be larger due to certain medical conditions, including:

A sunken soft spot is just as concerning, as it can be a sign of dehydration. If your baby’s soft spot looks like a significant dent in their head, begin tracking how much they are nursing or taking from a bottle. Depending on your baby’s age, dehydration can become dangerous quickly and will require treatment from your doctor. 

Craniosynostosis. In rare cases, a baby is born, and their skull fuses together too soon. This could impact brain development and cause your baby’s head shape to appear abnormal. 

Types of craniosynostosis include:

  • Sagittal synostosis: The sagittal suture runs along the top of the head from front to back. If the space fuses too early in development, your baby’s head may grow to be long and narrow. This is the most common type of craniosynostosis. 
  • Coronal synostosis: The right and left sutures run from each ear to the top of your baby’s head. Since these are two separate spaces, one side may fuse while the other doesn’t. When one of these gaps closes too early, your baby may appear to have a flat forehead on one side of their head. This may extend into the facial development on the side of their head that is impacted. 
  • Bicoronal synostosis: If both of the gaps going from your baby’s ears to the middle of their head close, they may have a broad and short skull.
  • Lambdoid synostosis: The lambdoid suture goes across the back of your baby’s head and may cause the back of their head to appear flat if the gap fuses too soon. 
  • Metopic synostosis: The metopic suture extends from your baby’s nose to the sagittal suture at the top of the head. If this part of the skull fuses too soon in development, your baby’s forehead may have a slight triangle shape. Additionally, the back of her skull will be broader. 

Remember, if you ever have concerns about your baby’s development, talk to your pediatrician. They can answer your questions and do an exam on your baby if they think it is necessary. It is better to address concerns sooner rather than later so that problems may be fixed before they lead to additional health concerns.