At your child's well visit, you’ve likely heard, your child is growing and developing well. Look, she’s in the 40 percentile. That’s great. And, while you’re happy to hear the good news, you might be thinking... what exactly does 40 percentile mean and how exactly is that great?
One of the first pieces of information I look at when a child comes in for a well visit is their height and weight. But more than that, I look at their growth chart. While the exact number is important, what is more important is the rate at which your child is growing. One static number in time does not give me a whole lot of information if I have no other measurements to compare it to.
This is where the growth chart comes in. Put 3 to 4 different heights and weights on there and now I can see your child’s pattern of growth. So, if your child weighs in at the 40 percentile and has done so for his previous weigh-ins -- this is a reassuring sign that your child is growing well at his own individual rate. Bigger numbers or percentiles are no better than lower numbers when you look at growth charts in this way.
Children come in a variety of healthy heights and weights. All of which are affected by genetics, eating habits, environment, daily activities and overall health. This is why we also look at proportions when it comes to your child’s height and weight. A child whose height and weight both fall into the 30 percentile is a good sign. While a child who has a height in the 30 percentile but a weight in the 95 percentile is more concerning and deserves additional investigation.
Body Mass Index (BMI) is a good measurement of this proportionality and is checked at each well visit from age two and up. A BMI less than 5 percent could indicate failure to thrive and greater than 95 percent requires intervention and management of obesity.
DR. MOM’S BOTTOM LINE:
^ The two most important aspects of your child’s growth chart is the rate of growth and proportionality. Any change in the rate of your child’s growth or a significant mismatch in proportion requires further evaluation.