Why Isn’t My Child Growing? Part 1
If you’ve noticed that your child seems smaller than their peers, or their height hasn’t changed much lately, you’re not alone.
Concerns about growth are one of the most common reasons parents come in to see the pediatrician.
This post will help you understand how pediatricians think about growth charts and what “normal” really means. My next post will go into more detail about abnormal growth and what happens if your child needs a specialist evaluation.
There is no “good” or “bad” number on a growth chart
One of the hardest parts of parenting is that there’s no clear scorecard. So when you finally see a number (like your child’s height or weight percentile) it’s easy to think it’s a grade or reflection on how you’re doing as a parent.
The Pediatrician Mom Tip: Your child’s growth percentile is not a grade. It’s just one data point that helps us look at the bigger picture of your child’s health.
There is no “good” or “bad” percentile. There’s simply a number.
And the “right” number will be different for every child.
Just as healthy adults come in all shapes and sizes, so do children. Even siblings can be completely different! Genetics plays a big role: petite parents (like me!) often have petite kids.
Why Do We Measure Height, Weight, and Head Circumference?
Because growth is a vital sign in children.
You already know about the classic vital signs (like temperature, heart rate, or blood pressure). But for kids, pediatricians also think of height, weight, and (for babies) head circumference as vital signs.
That’s because how a child grows can reflect their overall health. The most important thing isn’t how your child compares to others. It’s whether their own growth pattern stays steady over time. Consistent tracking along their personal curve is what we love to see.
Growth chart basics
In the U.S., pediatricians use two main growth charts:
The WHO curves for babies aged 0-2 years.
These are based on breastfed infants, who often gain weight more slowly than formula-fed infants.
The CDC curves for children over 2 years.
In certain cases, we use other specialized charts, such as the Fenton curves for premature infants or the Trisomy 21 growth chart for children with Down Syndrome
What do growth chart percentiles mean?
Growth charts show how your child compares to other children of the same age and sex.
If your child’s weight is at the 50th percentile, that means 50% of kids weigh less and 50% weigh more.
If your child’s height is at the 10th percentile, that means 10% are shorter and 90% are taller.
The Pediatrician Mom Tip: Being in a lower percentile isn’t necessarily a problem. What matters most is that your child is consistently following their own curve. Sudden changes (eg: dropping or jumping several percentile lines) are what usually prompt us to take a closer look
The balance between height and weight
We also look at how height and weight relate to each other. If both percentiles stay in roughly the same range, that’s usually reassuring. If one changes significantly while the other doesn’t (for example, a big increase in weight without height gain), we’ll want to understand why.
What if your child’s percentiles drop?
A single data point does make a pattern. What matters most is your child’s growth pattern over time (ie: how they’re tracking along their curve).
The Pediatrician Mom Tip: Growth TRENDS matter more than single measurements.
If your child’s height or weight suddenly looks different from what we’d expect, your pediatrician will often start by repeating the measurement a few weeks or months later.
The Pediatrician Mom Tip: Sometimes recent illnesses (especially viral stomach bugs) can temporarily affect appetite and cause mild weight loss. Most kids bounce back and return to their usual curve once they’re feeling better.
The bottom line
Growth is an important indicator of a child’s overall health.
Your child’s growth chart percentile is not a grade. It is just a reference point.
Consistent tracking along their own curve is what matters most.
Sudden drops or big jumps across percentiles are what usually trigger a closer look.
In my next post, we’ll go deeper into what happens if your child’s growth slows or stops. including what we look for, what labs or imaging might be ordered, and when a pediatric endocrinologist might get involved
