What age do the fontanelles close

Fontanelle Closures | Children's Hospital Colorado

Your baby has two places where their skull bones don’t fully fuse together in the first several months of life. These “soft spots” are fontanelles, a normal part of your baby’s development.

Issues with fontanelles, such as bulging or sinking, can be signs of other health concerns. Additionally, babies in the Neonatal Intensive Care Unit (NICU) or those with ongoing health conditions will have additional considerations related to their fontanelles.

Children’s Hospital Colorado neonatal experts explain how your baby’s fontanelles should feel and develop and when to seek care.

What are fontanelles?

Fontanelles are the soft spaces on your baby’s head where their skull bones have not yet fused together. These spaces allow for the skull bones to shift as needed during birth and for your baby’s brain to grow. They will close as your baby grows. You should keep your eye on two fontanelles:

Anterior fontanelle is located near the front, top of your baby’s head. This is the larger of the fontanelles.
Posterior fontanelle is located near the back of the head.

It’s OK to lightly touch your baby’s fontanelles. A healthy fontanelle should feel soft and flat. A bulging or sunken fontanelle may be a sign of a health issue.

When do fontanelles close?

Typically, fontanelles close by the time your baby is 18 months old. The posterior fontanelle usually closes first — within 2 months of birth. The anterior fontanelle closes between 7 and 18 months. If you feel your baby’s fontanelles are closing too soon or haven’t closed in 18 months, consult your pediatrician.

Fontanelle closure for babies with medical conditions

Premature babies or babies with ongoing medical conditions might have fontanelles close on a different schedule. Conditions like hydrocephalus and brain bleeds commonly affect when fontanelles close, although other conditions can have the same effect.

Your baby’s care team can tell you when to expect your baby’s fontanelles to close based on their condition.

Premature closure of the anterior fontanelle

Sometimes, the anterior fontanelle closes too early. This is known as craniosynostosis and can limit brain growth or create an abnormal head shape. If your baby’s doctor suspects craniosynostosis, they may recommend seeing pediatric craniofacial specialists or pediatric neurosurgeons. Contact your baby’s pediatrician if you feel their fontanelle has closed too early.

Delayed closure of the anterior fontanelle

Just as fontanelles can close too early, fontanelles that close late can also be a sign of medical issues. The most common causes of fontanelles closing outside the normal time range are:

Achondroplasia: A genetic disorder that affects cartilage and bone growth
Hypothyroidism: An issue in the thyroid gland that affects hormone production
Down syndrome
Increased pressure in the brain

What does a bulging fontanelle mean?

Sometimes when a baby cries or lies down, their fontanelle will bulge above the skull bone. This is normal, as long as the fontanelle returns to its regular position when the baby sits up or stops crying.

A bulging fontanelle when not crying or lying down, it may indicate a more serious medical issue, such as:

Hydrocephalus: A buildup of fluid in the brain
Encephalitis: Swelling of the brain usually caused by infection
Meningitis: Swelling of the membranes that cover the brain and spinal cord
Bleeding or pressure in the brain

A fontanelle that bulges when your baby is not crying, vomiting or lying down is a medical emergency. Call 911 or go to the nearest emergency room.

What does a sunken fontanelle mean?

A fontanelle that is sunken into the skull can also signal certain medical issues, including:

Dehydration: When your baby isn’t getting enough fluid; this is the most common cause of sunken fontanelles
Failure to thrive: Babies who are not gaining enough weight for their age
Malnutrition: Not getting enough food or having a very imbalanced diet

If your baby has a sunken fontanelle, contact their doctor immediately and seek care as soon as possible.

Fontanelle considerations for babies with medical conditions

Babies born early or with certain medical conditions may have different sized fontanelles than babies born at full term. A larger fontanelle can be a sign of various medical conditions. Your baby’s NICU care team will diagnose such a condition and arrange the right care. If you feel your baby’s fontanelle is larger than typical, talk to your care team.

Babies born prematurely also have a higher rate of bleeding in the brain, which can lead to hydrocephalus. If your baby had bleeding in their brain, pay close attention to their fontanelles and their head circumference. Talk to your baby’s care team if you have any concerns.

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When Does the Fontanelle Close?

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By Cashmere Lashkari, B. Sc.Reviewed by Dr. Catherine Shaffer, Ph.D.

A newborn baby can look quite unlike what is usually seen in the media. The head looks misshaped, the skin is blotchy and there are many wrinkles. However, within a few days, the features begin to change and the baby begins to look like a tiny version of the parents.

The one part of the baby that still requires care is the fontanelle. Fontanelle, also spelled fontanel, is derived from the Latin term fonticulus as well as the Old French word fontaine, which means fountain or little spring. The presence of the fontanelle is essential for the protection and proper development of the baby’s brain.

Image Credit: Demkat/Shutterstock.com

What is the fontanel or fontanelle?

The skull of a baby is made up of six different bones that are held together by a flexible, elastic tissue called a suture. There is one frontal bone, one occipital bone, two parietal bones and two temporal bones. Sutures are present along the edges of all six bones and hold them together to form the cranium.

When you feel along a baby’s skull, there are soft places where the bones are not quite knit together. These soft areas are called the fontanelles. They are bordered by the suture lines which will eventually close and produce a solid skull.

If the sealing of the suture is done along the sagittal suture that runs the length of the skull, a long and narrow head is produced. Should the permanent seal take place along the coronal suture, which tends to run from side to side on the skull, it will produce a short and wide-shaped head.

Different types of fontanelle in newborn babies

When the six skull bones are bound by suture lines, six fontanelles are formed along them. The two primary fontanelles are the a nterior fontanelle and posterior fontanelle. The anterior fontanelle is found between the frontal bone and parietal bones. The posterior fontanelle is located between the pair of parietal bones and the occipital bone.

In addition to these two larger-sized fontanelles, there are four smaller fontanelles along the sutures of the remaining bones. Two are known as sphenoid fontanelles and the remaining two are called mastoid fontanelles.

The sphenoid fontanelles are on the front side of the skull between the sphenoid bone and the parietal bone. The mastoid fontanelles are found between the temporal bone and the occipital bone. This fontanelle lies towards the rear of the skull.

Time taken after birth for the fontanelles to close

The anterior fontanelle takes the longest time after birth to close. It will take between 12 to 18 months for the sutures to solidify here. The fontanelle is usually closed by the time the baby completes its second birthday.

The posterior fontanelle closes much earlier. By the third month after the baby’s birth the soft spot on the rear of the skull is usually sealed up as the suture knits the bones together. As the suture solidifies, the back of the skull is closed completely.

The sphenoid and mastoid fontanelles also close up within a couple of months of the birth of the baby. They are small and so are not noticed by most parents as soft spots on the baby’s skull.

Skull fontanelles

Precautions to take while fontanelles are open

The soft bones and flexible sutures can cause the head of the baby to flatten out. Should the flat area appear at the back of the head it is known as plagiocephaly, while if the flatness appears on the side of the head it is referred to as brachycephaly.

The appearance of this flatness is directly related to the position the baby’s head lies in when he sleeps. Parents should encourage the baby to sleep on the back and when awake to rest the rounder part of her head on a pillow. A rolled-up towel or a pillow in the shape of a doughnut may also be used to take the weight off the bones.

To get the baby to look from one side to the other, change the position of a favorite toy. As the neck muscles grow stronger make him lie on his stomach. As the baby grows older and can turn his head and sit up the pressure on the skull will decrease and the flatness will round out into a regular skull shape.

Should the shape of the head still appear abnormal after the baby has reached the toddler stage, discuss it with the doctor. He may perform a physical examination of the fontanelles to see if there is any development issue with the cranial bones. Should a problem exist a physiotherapist may be able to help correct it.

References

Medline Plus, Cranial Sutures, https://medlineplus.gov/ency/article/002320.htm
BabyCenter, Soft Spots, http://www.babycentre.co.uk/x552709/what-are-the-soft-spots-on-my-newborns-head
American Family Physician, The Abnormal Fontanelle, http://www.aafp.org/afp/2003/0615/p2547.html
Kidshealth, http://kidshealth.org/en/parents/newborn-variations.html

When does the fontanel close?

Olga Lugovskaya, a pediatrician at the DocDeti clinic, will talk about the norms for closing the fontanel.

Fontanelles are areas between the bones of the skull that do not ossify immediately, but after a certain time. At the time of birth, the baby has six fontanelles:

1. Anterior fontanel (it has the shape of a rhombus).

2. Posterior fontanel (it has the shape of a triangle).

Fontanelles 3 and 4 are paired, wedge-shaped.

Fontanelles 5 and 6 are also paired, mastoid.

When passing through the birth canal, the bones of the skull can move precisely due to the presence of fontanelles. This is necessary so that during childbirth the child does not damage the brain and does not get stuck passing through the birth canal.

The size of the fontanelles is influenced by a large number of indicators:

1. Gestational age.

2. Genetic predisposition.

3. The state of metabolism.

4. The presence of diseases.

There are norms according to which fontanelles should close in the following sequence:

1. Lateral fontanelles, provided that the child was full-term, close by the beginning of birth.

2. The small fontanel closes when the baby reaches 2 months of age.

3. The large fontanel has the largest age difference. Its closing rate is between 3 and 24 months.

In 1% of healthy babies, a large fontanel can close by three months. Their parents should not worry, but they need to monitor the increase in head circumference monthly.

It is a very common belief that if the fontanel closes quickly, then vitamin D3 is contraindicated, as are dairy products. This is a big misconception - a myth.

Strange but true: the skull grows behind the brain. The brain has a very active growth, especially before the age of two, so the cranium also increases significantly in size. The bones of the skull do not grow due to the fontanelle, but due to the fact that each bone grows in the central part and due to cranial sutures (the border between different bones of the skull).

The suture of the frontal bones closes by 2 years of age, but all other sutures are open until the brain stops growing, at about 18-20 years of age.

Let's summarize:

1. The individual characteristics of the child set the deadline for closing the large fontanel.

2. Mom's diet and intake of vitamin D3 does not affect the rate of closure of the large fontanel.

3. If a large fontanel closed early, then you need to carefully monitor the increase in head circumference. If the growth rate has slowed down, then a qualitative and careful assessment of a pediatrician is needed. It is necessary to exclude the causes that can lead to microcephaly (small skull size).

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Large fontanel in newborns.

Examination IPM Clinic for Children Krasnoyarsk

07/26/2017

The birth of a baby is a very important and joyful event in the life of young parents. After birth, there are a lot of questions about the health, care and proper development of the baby. The very first questions are often asked about the fontanel.

Fontanelle - soft, non-ossified area of the cranial vault of newborn babies, consisting of remnants of the membranous skeleton and connecting the bones of the skull. In the area of the fontanelles, a pulsation of the arteries of the brain and membranes is felt, which is why these areas are called pulsating, gushing. Fontanelles allow you to “compress” the cranial vault during childbirth for a better passage of the baby through the birth canal. Four of them close in the first days of a child's life, the fifth in the second month of life, and the sixth, the largest (anterior), closes from 3 to 24 or more months. Very often, fontanelles and the pace of their closure cause great concern to parents.

The role of the fontanel:

The growth of the bones of the skull depends on the growth of the brain. The fontanelles provide elasticity to the skull during the most rapid growth. This period is from birth to two years of a child's life.
Fontanelles also protect the baby's skull from injury: upon impact, the possibility of elastic deformation of the skull remains, which dampens all the kinetic energy of the impact and protects the child.
The brain of a newborn baby is very sensitive to overheating, and a kind of natural “window” brings excess heat out and naturally cools the meninges, thereby playing an important role in the processes of heat transfer and thermoregulation of the body.

The size of the anterior (large) fontanel varies greatly. On average, the normal size of the fontanel at birth is 3.0 * 2.5 cm, it has a diamond shape.

As the baby actively grows and develops, the free space between the bones gradually hardens and decreases in size, the pulsation becomes almost imperceptible.

The timing of fontanel closure may vary. On average, complete closure occurs by the year (normally also up to two years).

When the fontanelle closes too slowly, the parents start to worry. But premature closure also does not speak well.

Causes of the “big” fontanel:

- Achondroplasia (hereditary disease)

- Down Syndrome

- Hydracephaly

- Premature birth

- Neonatal Hyphyeriosis

- Rachit

Rachit slow closure of the fontanel. Most often, rickets develops in premature babies and in children who do not receive preventive treatment with vitamin D. In a child with rickets, the edges of a large fontanel are flexible, the back of the head flattens, and characteristic bone thickenings form on both sides of the sternum.

The change in the appearance of the fontanel also indicates a number of certain problems: