Growth Charts: Everything You Need to Know About Your Child's Growth

Originally published: Oct 23rd/2018; Updated: June 18th/2019

Are you wondering if your baby’s growth is normal in the first years of life? Learn the importance of growth charts, understanding percentiles, and what it means for your child.

Is my child’s growth normal?

It’s a fair concern! All parents want (and worry about!) their child to have normal growth.

Your doctor monitors growth by measuring weight, height, and head circumference.

Health and nutritional problems will likely affect your child’s growth. That’s why monitoring your infant’s growth is an easy way to assess any problems they may have.

What is even better is a repeated measure over time, so that you can assess the pattern of growth. Having regular checkups at the doctor’s office are key!

Regular growth measures can help and prevent potential health or nutritional problems.

Understanding infant growth charts for parents

The first 12 months: exponential growth!

By your child’s first birthday, they will have tripled in size! Talk about rapid growth (don’t you just keep on buying bigger and longer clothes?!).

Like pregnancy, weight is the “best” indicator of adequate growth. Measuring length and head circumference provides valuable insight on your child’s growth.

Look…it isn’t a perfect system, but an easy one to screen for more serious problems.

Your doctor measures growth using length, weight, and head circumference. These are easy and accessible measurements to screen for health problems.

Growth charts 101

What can influence your baby’s growth?

In short, so many things!

Sex
Size at birth
Gestational age at birth (prematurity)
Health condition
Genetics and parents’ size
Mother’s lifestyle during pregnancy
Feeding mode: breastfed or formula fed, eating solids
Age and stage of development: walking, crawling, running
Illness and sickness
Sleep pattern
Family dynamic
Appetite and physical activity level

Many factors can influence your child’s growth, from genetics to appetite!

Growth chart 101: what is that?

Doctors use growth charts (or curves) to track your child’s growth.

The World Health Organization created these charts by sampling a large number of children all over the world. Children included were all healthy, breast fed, and from different ethic backgrounds.

The population used to develop growth charts represent the normative model for optimal growth and development. In other words, they suggest the range of weight and length an average healthy kid should gain over time.

Growth charts allow us to track the head circumference which represents brain growth. They also track weight and length gain over time for your child, based on sex and age.

Note: “length” applies to children before 2 years, because they lay down for height measures. Afterwards you’ll see the term “height.”

Below is an example that shows a growth pattern of a baby boy over time. The top curve displays the body length, while the bottom curve is shows weight gain.

Red dots show the measures taken at each doctor’s visit.

Repeated measures over time help track growth and observe patterns of development. Using the same person, equipment, and taking measures in the same manner help accuracy.

Growth charts allow us to capture the pattern of your child’s growth over time.

Growth chart 101: what is a percentile?

The growth charts display the normal age-related weight, length, and head circumference.

Global data from thousands of kids’ growth help establish these reference values.

Percentiles (from 3 to 97) represent the normal window of growth we can expect for children.

The 50th percentile shows the average. This is where most children are.

It means that below 50th percentile is lower than the average, but still normal. Above 50th percentile is above the average, but still normal too!

What if your baby is on the 75th percentile for length? In this example it means they are 75% taller (and 25% shorter) than babies of the same age.

Now this is different than what we may associate with average, and being above the average – but this isn’t a math test!

Higher doesn’t mean better. There is nothing to aim for. The ideal target is to be within the average, between 3th and 97th percentile.

Also, it’s ideal for your child to follow a specific percentile over time, with repeated measures.

Children often follow the same percentile for length and weight. For example, a child in the 15th percentile for weight, will often be in the 15th percentile for length.

These two measures can grow in parallel. But, it is not uncommon or bad news if your kid changes percentiles in the first three years of life.

Your child will grow to their genetic potential. They will reach their natural weight and natural length. Genetics will win!

After 3 years, growth should be steady. Percentiles shouldn’t change much until your child reaches puberty.

The best comparison for your child is themselves. Your child will grow according to his/her genetic potential

Growth chart 101: does it matter if my child is not on the 50th percentile?

It doesn’t matter. Bodies come in all shapes and forms. There is no “goal” to reach here. Your baby is born the way s/he is and it is perfect this way!

Your child will reach his/her genetic potential, whatever that represents in percentile.

There is no “goal” to achieve. Focus on ensuring your child is healthy and fed to support their natural growth!

Growth chart 101: is it better to be above or below the 50th percentile?

It doesn’t matter. Nothing is better. Even being on the 50th percentile is not “better”.

It’s more important that your child follows their own growth pattern. The percentile is less important.

Sudden drops or spikes in percentiles are cause for concern. Why? well it may show a potential health problem or inadequate food intake.

Bodies (even your baby’s) come in all shapes and forms – that is the beauty of it!

Growth chart 101: the right growth charts for your child

Different growth charts exist for preterm infants and infant with special health conditions.

Tracking these children’s growth is important. But, using the right growth chart and comparing them to similar children is key. This is because their expected growth pattern will be unique.

If your child was born premature, or has special needs, it is important to track their growth too. Such children need unique growth charts for their needs.

Growth chart 101: it is so hard to get a single measurement

Have you already visited the doctor for a checkup for your child? It can be challenging to measure weight, length, and head circumference with accuracy.

They move, they wiggle, they cry, and they don’t particularly like it.

Unfortunately, it does influence the validity of measurements taken.

Another issue is the difference between best practice, and what actually happens. Measures at your doctor’s office depend on equipment availability, time, and cooperation.

For babies under 2, the best way to measure length is to use a length board. This is “recumbent length” and gets measured while laying down.

Here babies lay down with legs extended, and their heads touching the top of the board. Then the footboard slides towards your baby’s heel to mark their length. See an example below:

Example: Hopkins Measuring Mat

For older kids, standing height gets measured using a stadiometer fixed to the wall.

This is where the kid stands tall, and the movable headboard is touching them to give the reading.

The best way to measure weight is using an infant scale. It’s easier when baby can lay down or sit on the scale without help, to ensure accurate readings and safety.

Babies are challenging to measure even under the best conditions!

Growth chart 101: the trend over time tells more than a single measure

Repeated measures, taken in the same conditions over time is what we are looking for.

This is what tells us if your child is growing well. A single measure can tell us a bit, but not much! But having several measurements allows us to see the growth pattern and trends. It also allow us to see if there is a decline or incline in the growth.

Moving between percentiles can be normal during the first three years. But, your doctor will judge when it is abnormal.

What is suggestive of a health problem? Seeing a sharp incline or decline in growth, or jumping up/down percentiles. This is a situation that warrants monitoring.

Ask your doctor to show you your child’s growth chart and review the pattern of growth together.

Infant growth: why and when to worry

Are you worried or planning to visit your doctor? Growth charts, a full medical history, and examination will help screen for problems.

The clinical judgment of your doctor is important in assessing when it’s time to worry.

When to worry? Gaining too little weight

Inadequate food intake or a health problem can alter your child’s growth.

In most cases weight is first affected, whereas, effects on length (height) happen later on.

Cases with long term or frequent health problems can lead to a negative impact on your child’s height. It means they may not grow as tall as their genetic potential.

Failure to thrive is the term used to describe when a child is not growing as expected.

See this growth chart example. You can notice a decline in weight (bottom curve) and a later decline in length (top curve).

Several things could explain the flattening of the curve:

Is the child getting more active?
Are you breastfeeding or formula-feeding?
Is the child eating less than usual?
Has the child been sick lately?
Has anything changed in the child’s routine?
Have any health problems occurred?

Most of the time it’s due to inadequate food intake. The good news is that it is reversible by adjusting feeding approaches. The guidance of a registered dietitian can help parents.

We recommend regular visits to your doctor to track your child’s growth. This will also provide the occasion to bring up any growth concerns you might have.

When to worry? Gaining too much

Should you worry is your baby is gaining too much weight? Not necessarily! See this example of a child who is starting to move up to a different percentile on the weight curve:

Growth spike example

This shows an incline in the weight (bottom curve) with a steady growth in length (top curve).

Does that mean this baby is gaining too much weight? Not necessarily.

Parents should consider the following questions:

Is the child eating more than usual?
Is the child less active than usual?
Has the child been sick lately?
Is this child breastfed or formula fed?
Has anything changed in the child’s routine?
Have any health problems occurred?

This situation is like when a child isn’t gaining enough. The doctor will track growth and discuss with the parents.

From the child’s general health, to any concerns, parents work with doctors on an action plan. Knowing what steps to take next will help ensure the child is growing to their potential.

Tracking weight and length gains over time help detect abnormalities. Often it comes down to issues like feeding problems that need alterations.

In the end, don’t over stress and don’t panic. As parents you’ve likely noticed all the subtle changes in appetite, food intake, physical activity, mood and sleep patterns of your child. The growth charts just add one more piece to the story.

It’s important to monitor growth so we can catch any problem early on. We want all kids to grow healthy and happily, and most of the time readjusting our nutrition strategies can help them thrive.