Stabilization of growth percentiles

[Anonymous]

Anonymous wrote:

Anonymous wrote:The growth curves are artificial lines. The scientists did not measure kids over time and create a curve for each kid. They plotted every the data points for every kid at every age, and created lines connecting the 95th percentile weight at every age group, whether it belonged to kid A, B, C at age 2 or kid X, Y, or Z at age 3. These curves are the bane of the existence of pediatricians who understand this, and are misinterpreted by pediatricians who don’t.

So how should we be tracking our child's growth trajectory?

DP but why do you need to? Unless you suspect a hormone issue there’s literally no need.

[Anonymous]

Anonymous wrote:

Anonymous wrote:The growth curves are artificial lines. The scientists did not measure kids over time and create a curve for each kid. They plotted every the data points for every kid at every age, and created lines connecting the 95th percentile weight at every age group, whether it belonged to kid A, B, C at age 2 or kid X, Y, or Z at age 3. These curves are the bane of the existence of pediatricians who understand this, and are misinterpreted by pediatricians who don’t.

So how should we be tracking our child's growth trajectory?

PP. We don’t need to track our kids’ growth trajectory other than using the chart to determine unusual growth trends. For example, a kid that was 25th for both height and weight jumps to 99th for weight and remains 25th for height. Or a child that was 75th for height is 5th a year later.

This article does a better job explaining it all.

https://www.nytimes.com/2020/04/17/parenting/growth-chart-accuracy.html?unlocked_article_code=1.hlA.fgEG.TZFqOF0eCpH_&smid=nytcore-ios-share&referringSource=articleShare

The problem is that the charts are out there and it’s really hard not to look at those curves and not see a projected path. My kid “fell off” from 99th for height last year and even though I know how the growth charts were created, I had a twinge of “I need to do something!” But he’s a 14 year old boy who is just starting puberty, so I had to talk myself off the ledge and acknowledge that he’s going to grow when he’s going to grow.

Here is an example of what individual growth curves look like. Some kids start and end up at roughly the same percentage. Some do not.

https://www.researchgate.net/figure/Individual-height-growth-curves-for-a-103-boys-and-b-74-girls-The-same-growth-curves_fig2_259243964

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:The growth curves are artificial lines. The scientists did not measure kids over time and create a curve for each kid. They plotted every the data points for every kid at every age, and created lines connecting the 95th percentile weight at every age group, whether it belonged to kid A, B, C at age 2 or kid X, Y, or Z at age 3. These curves are the bane of the existence of pediatricians who understand this, and are misinterpreted by pediatricians who don’t.

So how should we be tracking our child's growth trajectory?

DP but why do you need to? Unless you suspect a hormone issue there’s literally no need.

Since you asked, no real reason other than curiosity to see each year how much my kids have grown. Plus I am short and my son is 6'2" at 15 so add curiosity because I'm also adopted and he is my first genetic relative.

[Anonymous]

It will probably change a lot. Two of my kids were huge as young kids 99th percentile, but ended up average sized adults. The other was always average sized and ended up that way as well.

[Anonymous]

Anonymous wrote:It will probably change a lot. Two of my kids were huge as young kids 99th percentile, but ended up average sized adults. The other was always average sized and ended up that way as well.

Or it might not. Granted I still have teens, not adults, but my kids have stayed at their respective percentages up until now (one at 50% weight/50% height and the other at 10% weight/25% height).

[Anonymous]

Anonymous wrote:It will change during puberty unless they are right in the middle with timing. They may go up in percentile if they start puberty early, or lose % if they are late bloomers. percentiles don’t mean much around puberty because of growth spurts…

Yup.

I've known multiple kids who were 99th percentile in elementary and were 50th percentile by the time they finished HS.

If you want to guess how big your kid will be then look at you and your spouse's height.

[Anonymous]

Anonymous wrote:

Anonymous wrote:It will change during puberty unless they are right in the middle with timing. They may go up in percentile if they start puberty early, or lose % if they are late bloomers. percentiles don’t mean much around puberty because of growth spurts…

Yup.

I've known multiple kids who were 99th percentile in elementary and were 50th percentile by the time they finished HS.

If you want to guess how big your kid will be then look at you and your spouse's height.

And grandparents’ height if you know, but that can still only give a rough idea, since height is polygenic. There can also be a huge amount of variation between siblings, so there is really no simple formula. You just have to wait and see.