So confused by percentiles

[Growthexpectations]

My pre schooler got measured today. Just gone four and is 108 cm. Since two he was on upper percentiles (80+) but last two measurements has been quoted as 25th and 30th percentile. He's really tall compared to some of his friends and the same size as others, not many taller so I queried how he could be on the lower range and was told it was because of calculating months. Fair enough. I them went on the internet and can only really find things that say he's closer to my original estimation of 80%.

Am I wrong here? Every time I bring it up they just dismiss it, but I'd like to know as it'll obviously effect if he is a healthy weight or not. Again, not worried as such but just to monitor.

Can someone explain to me?!

So are the friends he's the same height as the same age by month? Because if they're younger that's what it means. The WHO publishes percentiles by month I think until 4. So if you have his height you just put it in there.

Who holds the measurements you are disputing? Who are "they"?

The doctors. The measurements are accurate although she potentially took off a cm or two but as he has just turned four (a month ago)and is 108cm already how can he be on the lower end with those measurements? It's just such a huge jump that doesn't tally with real life, measurements elsewhere etc

Did you ask the doctor what they measured him as? And what charts they are using? What do they estimate as 50th %tile. Not sure the charts you find on the internet are v helpful, as they could be using diff ones. What does his red book say?

I mean looking at the Who charts he'd be around the 75-90th which is consistent with his growth so far and what I thought.
Just trying to work out if I am being thick or have they got it wrong?

I'll have to look. I haven't looked at the red book since they stopped measuring for a while around two then these new measurements were taken separately.

I just think it is a bit weird as that's a huge difference.

It's likely you have a growth spurt due soon.

Possibly, but according the who data he's already in the top percentiles for his age. I already get comments that he is so tall and he is as tall as many reception children so I'm finding the concept just baffling. Do the NHS use wildly different ones? It's just bizarre and I can't get my head around it.

His measurement is 108 cm. Above average according to the picture you have posted.

What is the "quoted as" actually quoting from? There will be a list of measurement with corresponding centiles - where have they found this list, is it in the red book?

That does seem a big drop, even accounting for the fact they all have growth spurts at different times. I wonder if they're using a different reference to what they were before. Or someone's typed something in wrong somewhere. The doctors obviously aren't bothered if they're dismissing you but I'd want to know what's going on too!

I'm not sure. He had all his doctor's notes in a folder. He said we'd get a letter but when we got it previous it just said the height and percentile not how it was calculated.
Yes I will double check with his red book later but it doesn't seem to add up. I just felt a bit shamed at the appointment as I'm not good at maths and he corrected me like I was thick. I definitely have the measurement right as the nurse that took it made a joke around it too.

Weird.

It's not uncommon to have a rogue bad measurement. It can be as simple as child slouching or heels not right up to the wall or the measurement taken at a different time of day even (we lose a centimetre or two over the course of a day due to the effects of gravity slightly compressing the spine for example).

If he's 4+1m (i.e. 49m old) and 108cm he is definitely btw 75-91st centile for height. A good table is here: https://www.rcpch.ac.uk/sites/default/files/Boys_2-18_years_growth_chart.pdf

It is possible that the dr underestimated his height or you overestimated it by a cm or too. And if both those things happened i.e. his true height is 105 cm, you overestimated it and the dr got it at 103 that would get you down to the 50th centile line. BUT that's still not as low as 25-30th centile.

I doubt you could have made an error as big as 8cm which is what you'd need to make him that short! So hard to guess what went wrong here.

If it is worrying you call the HV and ask for advice and possibly a remeasure. Don't worry too much about calculating BMI now unless you are already concerned he is over or underweight for his height. BMI is not an especially helpful measure in children under 5 who can get chubby then thin out as they grow quite dramatically in the space of a few weeks. Its only if he seems very slim or large for an extended period of time and you have additional worries about his diet that calculating his BMI may be helpful.

Yeah I mean I that's the thing, I want to know I'm not missing anything huge as growth can obviously be an indicator of something else. It's just that his height, our experience of comparison all tally with his previous percentile and not current. The doctor said as long as he was going along fine but he's dropped from 30 to 25 according to them over six months so given the huge drop you'd think they'd be interested.

Thanks. I watched her take the measurement and if anything she underestimated, but like you say it wouldn't have come up that low. I'm wondering if it is something as simple as they think he is five not four maybe?

It's also just weird I queried it both times and both times told I was wrong.

Whilst it seems likely you are right and for whatever reason the dr reading was wrong I doubt there is much to worry about. My three all treated centile charts as trampolines. The eldest managed to swerve btw 0.04th and 91st for weight over the course of her infancy! She's a normal sized adult now.

I just checked in my red book at 108 cm at 4yrs 1 month is def tall. I think this must be an administrative error by the doctor. Very out of order that they dismissed you and made you feel silly. I’d go back and query what they have recorded his height as, as I’m betting it’s wrong.

Thanks I will dig out the previous paperwork as well and check it against our own height records. Yes, it just seems odd and I just want to make sure he is ok for weight too as they reckoned the 50th but again, who knows if accurate.

Haha that made me laugh. Thank you!

I think he may have been recorded as five years old not four, as that would put him around the 30th

Obviously I will have to double check but it's a shame no one double checked when I queried it. 🙄

Sorry if I'm a bit off topic, but is it common for GPs to actively follow children measurements still when they are 4yo?

I'm just wondering why/how those measurements came about, my eldest is 2 and his height has never been measured since they don't always do it at birth, and his last weighting was at a 12 weeks I think.

We did opt out of HV appointments so that might be the part of the reason, but our GP has never asked to follow-up on these either.

No we had a medical reason I'd rather not disclose which is why he is being monitored. I would just prefer them to be accurate as obviously height and weight effect all sorts of medical things.

Ah fair enough! I was wondering if I had missed something!

You and me both. Starting to doubt myself and thinking have I lost a year? Is he really five?!

HV usually record at the age 3 developmental check. GPs don't routinely record BUT often need to assess if prescribing meds which might be the reason - e.g. my child had their height and weight calculated frequently to prescribe steroids for asthma when young as the dose is weight dependant. In these circs the relationship to the child's overall devt is irrelevant and GPs are not child health specialists which may be why they filled in the chart wrong.