Soft Spots on The Baby's Head or Fontanelles

The soft spots on your baby's head, known as the fontanelles, can feel a little strange and many parents are wary of touching them. This concern usually arises from a lack of information about what these soft spots are and how they should be treated. The fontanelles have a number of purposes. They play an important role in your baby's birth and continue to be an indicator of health for some time afterwards.

What are the fontanelles?

Your baby will have two soft spots on his/her head. There will be one on the top of the head, which is known as the anterior fontanelle. This is a kite or diamond shape and measures between 4 and 5cm. It will also feel soft to the touch. The other will be at the back of the head and is usually triangular. It is smaller and known as the posterior fontanelle. It can be difficult to feel the posterior fontanelle so do not be surprised if you are unable to find it.

What do the fontanelles do?

The fontanelles are nature's way of helping the largest part of your baby, the head, pass through the birth canal. Before your baby is born, the bones in the head are soft and can move around. During the birth, in a process that is known as moulding, the bones slide over one another to allow your baby to manoeuvre through the birth canal. This is why some babies are born with a cone shaped head. Do not be alarmed if this happens as the bones move back into their normal position in the days following the birth.

These soft spots will also enable your baby's brain to continue to develop. During the first year, your baby's brain will continue to grow very rapidly. If the skull was closed and in a fixed position then there would be nowhere for it to expand to.

Can I touch them?

Some parents are a bit reluctant to touch their baby's soft spots and are concerned that they could hurt their baby. Although there is not yet any bone in the area where the soft spot is, it is covered by a thick membrane which offers protection. It is fine, therefore, to gently touch the soft spots, although you should avoid putting direct pressure on them.

When do they close?

The soft spots disappear as your baby's head grows and the bones fuse together. The posterior fontanelle, on the back of your baby's head, usually closes within the first six weeks after birth. The anterior fontanelle, on the top of your baby's head, takes longer and usually closes between 12 and 18 months.

Routine checks

Your baby's fontanelles will be checked after the birth by the midwife or paediatrician. They will also be checked by a health visitor to make sure that they are developing correctly. If you have any concerns about their development then you should speak to your health visitor or GP.

What happens if they don't close?

In rare cases the fontanelles do not close within the normal time frames. This is usually the sign of an underlying condition such as hydrocephalus ("water-on-the-brain") or rare conditions such as developmental delay or dwarfism.

Health indicators

The fontanelles are important as they can give an indication of the health of your baby. If your baby is well then they should appear flat. It usual for the soft spots to move when your baby breathes, laughs or cries.

If the fontanelles are sunken it can be because your baby is dehydrated and needs fluids, particularly if they have also been vomiting, have diarrhoea or are having trouble feeding. If this is the case then you should seek medical advice.

If your baby's soft spots are bulging it can be a sign of illness. It is normal for them to bulge slightly if your baby is crying, although they should return to normal once your baby is calm. If, however, they are persistently bulging it can be an indication of meningitis and urgent medical attention should be sought.

Your baby's soft spots or fontanelles have an important role to play in the growth and well being of your baby. They help the baby to pass through the birth canal, they enable the brain to continue to grow during the early stages of the baby's life and they serve as an indicator of the baby's health. As he or she continues to grow they will slowly disappear as the skull bones fuse together. This coincides with the change from being a baby and turning into a toddler.