Sometimes, people wonder why some parts of a newborn baby’s skull appear soft and delicate while the rest of the skull is hard. The hard part is the skull bone, covered by skin; while the soft portion is a tough membrane, covered by skin. The soft portions, which represent gaps in-between the skull bones, are referred to as fontanelles.

Why are there gaps in-between skull bones?

The gaps between the skull bones of a newborn baby are for the purposes of:

1. Moulding – The process that occurs during labour, which allows the bones of the skull to slide under or above each other in order to reduce the size of the head and allow easy passage of the fetal head through the birth canal.
2. Brain growth – Allowing the gap in-between skull bones gives room for the brain to continue to grow after delivery without creating tension for the brain tissue.

How many fontanelles there are?

There are two main fontanelles on the head of every normal newborn baby: anterior (front) and posterior (back). Anterior fontanelle is diamond-shaped while posterior fontanelle is triangular-shaped. Anterior fontanelle is much larger than the posterior.

How long does it take the fontanelles to close?

The smaller posterior fontanelle closes about 2 to 3 months after delivery while the larger anterior fontanelle closes between 9 and 18 months. If the closure occurs earlier than these, it is important to see a doctor.

Is there anything to worry about the fontanelles?

There is nothing to worry about the fontanelles because they are natural occurrence and are there for a purpose. The bigger anterior fontanelle usually pulsates, corresponding to the baby’s heartbeat. The pulsation has no effect on the baby in any way. It is just a reflection of heartbeat. The fontanelle may bulge when a baby cries. It returns to its normal state thereafter.

Do the fontanelles have any health benefit?

The fontanelles (especially the anterior) may serve as an early pointer to disease conditions such as:

1. Dehydration – The anterior fontanelle becomes sunken when a baby is dehydrated. This, in addition to other signs like poor feeding and dry diapers, may be a clear indication of illness in the baby, which need urgent doctor’s attention.
2. High pressure inside the skull – The anterior fontanelle bulges when there is increased pressure inside the skull such as in disease conditions like meningitis. Other symptoms like fever, vomiting and poor feeding may also be present in such conditions.

If any of these signs is seen, it is time to see a doctor.

Is there need for special care for the fontanelles?

Some persons apply traditional medications to the spots, especially the more prominent anterior fontanelle, in their belief that the baby may be feeling pain due to its pulsation. It should be noted that the baby is not feeling any pain due to the pulsation of the fontanelles.

Therefore, there is no special care required for them. They should however be handled with care and direct pressure to them should be avoided so as not to cause injury to the brain underneath them.