Making Sense of Height Percentiles (Medical Topic)

[Aelwydd]

Maybe someone here can help me understand height/weight percentiles for children (mostly height here).  I'm hoping that especially nurses or doctors or other medical professionals may weigh in with their perspectives.

 

My question is this: If you and your spouse are both under average for height, and your child went from being in the 97th percentile for height (at 2 years of age) to the 25th percentile over the years (he is now 12 yo), would you say that the decline is more indicative of his genetics, or would you suspect some other factor is affecting his height?  This did not occur over the space of a year or two, BTW, but happened more gradually over childhood, i.e., 90%, 87%, 75%, 50%, etc.

 

DS has asthma, but it is typically well controlled.  He is physically active, plays two different sports, and is slender, though he has very good muscle tone. His diet consists of mostly Indian and Asian dishes, (along with snacks like crackers and fresh fruit), because dh cooks and is vegetarian.  DS does eat small portions of meat a few times a week.  He does not drink milk, except as a flotation device for his cereal. :glare:   He doesn't go to sleep early enough most nights, IMO, however.  He tends to be a night owl and likes to stay up late. 

 

So, overall he is healthy, and he does eat much better than I did when I was his age.  I tend to think that the fact he is shorter than most of his peers owes to his genetics from his dad and myself.  But, the drop in percentile is quite large and I've been concerned about it.  When he had his well check up last week, the pediatrician projects that ds will hit a growth spurt around 14 and end up taller than dh. 

 

Can anyone here relate? Is this a fairly normal phenomenon? TIA!

[Momling]

Also, at 12, you've got puberty to consider. A child entering puberty later will be in a lower percentile for height at 12 than a child who's already had a growth spurt.

 

It'll all even out in the end...

[StephanieZ]

Sounds to me like genetics for ultimate height are being expressed, over-ruling the great-nutrition large baby syndrome, lol. My babies were all fairly big and chubby (Smallest was 7'15, other two were 8'6 and 8'8), likely due to my good nutrition and good health status while pregnant. As babies, they stayed healthy, but being exclusively breast fed and active babies, they all slimmed down by their second year, to their ultimate slim-kid destiny. Although they were all fairly high on the height charts as babies/infants, they each charted their own paths as they got older and, I believe, their genetics overcame their early nutritionally-driven size.

 

So, anyway, I wouldn't hesitate to ask the doctor about it at his wellness checkups, just to be sure no medication or health condition is impairing his growth, but my expectation would be that he just won't be a very large kid/teen, but that, who knows, he might be one to grow until he is 20, and growth spurts are also unpredictable, so there's no guarantee about his ultimate height until he is 20 or sol. 

[Laura Corin]

Yes - genetics plus puberty.  Calvin was always at the 97th percentile, even though I'm 5'4" and Husband is 5'6".  He went into puberty early and for a while was still much taller than his peers.  They all caught him up and most overtook him.  He's now just over 5'10", which is the limit of his expected genetic height.

 

FWIW, I took Hobbes to see a specialist paediatrician when he was twelve because he had fallen off his height line.  The doctor did an examination and said that he was late into puberty and would grow two inches a year for the next few years, but might not be taller than 5'7".  So far, that's coming true.  If you are concerned, another doctor's appointment might be a good idea.

 

We eat a high plant, low meat diet.

[TeacherZee]

I was the second tallest girl in my 3rd grade class. If I stood next to those girls today I have no doubt I would be one of the shortest. I hit puberty early. Ask if you are concerned but it sounds fairly normal.

[TammyS]

OMG, ignore the charts.  Those charts are the devil and take into account a very select version of "average".  My son is tall (6'8") and has been "underweight" his whole life, according to the charts.  Yet, I know he's not.  He's just one of those long, thin people.  He has substantial muscle mass, little fat, and a lot of height.  He eats well and sleeps well.  There's really nothing to be done about upping his weight, other than feeding him junk food, which I'm not willing to do.  His father was also very tall and thin and so was his grandfather.  It's genetics.

 

It looks like you are doing well with your son.  As long as he's healthy seeming (good energy, no trouble concentrating), growing regularly, I wouldn't worry.  If you want to work on something, I'd work on the sleep and make sure he's getting enough (though when he gets it is less important).  Probably when he hits puberty it will take care of itself.  My son regularly sleeps at least 9 hours per night.  One year, he grew 15"!  That year he slept about 11 hours per night.  Genetics will out.  Your son's genetics will pretty much take care of things on their own, as long as he gets enough food and sleep.

 

My only real advice: get ready for the grocery bill, omg.

[Miss Tick]

Not the OP, but thanks for everyone's responses! The Hive always comes through for me. My 6yo slid down a percentile curve at her check 2 weeks ago and the Dr wants to see her at 6 months, but wasn't clear to me about why. Glad to hear some actual stories.

[catz]

I think the growth charts are weird. Expecially for boys. My son was a tiny newborn. Turned into a kind of tub-o-lard, big breast fed baby. A nice roundish toddler that kept dropping in the growth charts to something like10th for weight and 20th for height. His weight from age 5-12 just crawled up the scale. Then something magical happened called puberty! He has grown 8 inches and gained like 20 lbs in a year. He is still not giant at 100 ish pounds and 5'6", but I also suspect he has more growing to do. He definitely looks all teen now, where as he was looking like a tiny boy for a long time. I suspect he'll end up in the 5'9 -5'11" range. Which is DH height. He is built like him too, long and lean. Did I mention he is 14. He has definitely been all over the growth chart.

 

ETA FTR i was the shortest kid in my kindergarten class. One of the taller kids in my 6th grade class. And short by high school grad at under 5'3". My dd is not following the same curve as me. I think she will hit puberty later and end up taller, but talk to me in a year. ;)

[SparklyUnicorn]

My experience has been similar with my older son and with me as a kid.  I was off the charts small by about 13.  Yet I was born average and remained average until around 10. 

[Alice]

It sounds like he's where he should be based on parental height. Growth charts are useful for me as a pediatrician to track trends in growth. I don't really care if a kid is 3% but I do care if their growth has plateaued. And I care if they are third percentile and the rest of their family is 90%. So it's a tool that is useful for roughly following growth. I have had times where the growth curve showed us a problem before their were other symptoms. But like any imprecise tool, it can be used ineffectively if it's not looked at along with other factors.

 

The best, but rough guess of ultimate height for boys is to take Mom's height and add 6 inches. Then average that with Dad's height. Take the resulting number and that's the "mid-parental height". Two inches on either side of the mid-parental number is considered the "genetic potential". (For girls you take Dad's height and subtract 6 inches, average with Mom's and that's the mid-parental height.) So for a 5'2" Mom and a 5'10" Dad as an example... a boy would have the mid-parental height of 5'9", with expected utlimate adult heigh of 5'7"-5'11". A girl would have the mid-parental height of 5'3" with an ultimate expected height of 5'1"-5'5". Those are fairly big ranges and there will be people that fall above or below expected but it gives you an idea. You wouldn't expect a boy in the above example to be 6'3", nor would you expect him to be 5'3". 

 

Before people start writing in with examples that don't fit this...it's a ROUGH estimate. I use it most often when I have a patient who is small but has shorter than average parents and the parents come in concerned about growth. It can help reassure the patient and the parents that they are where they should be. We aren't going to be worried if they look like they are plotting to fit into their expected range based on parental height. We are more worried if they are way off the expected. 

 

Puberty definitely is also an issue. There is a term called constitutional growth delay which is a stupid term but basically just refers to people who go through puberty later and so have their growth spurt later. What makes you stop growing is puberty because the sex hormones make the growth plates of your bones close. Closed bones, no more growth. So a kid who is shorter than expected as a 14 year old but whose Dad remembers "growing a ton in college" is going to be less of a concern than a kid who is shorter than expected as a 14 year old and who is already fairly far into puberty. 

 

I would guess that the change from when he was 2 has to do with the fact that a lot of babies and toddlers are much larger than expected genetically from nutrition factors. Breastfed babies tend to be very large on the curve and eventually they "find their curve" meaning that they drop down percentages until they find where they are supposed to be genetically. 

 

If your son has been growing along the curve he's on now for awhile, I wouldn't be worried. If he's been steadily decreasing it MIGHT be something other than genetics and you could talk to your pediatrician about doing some simple tests to look for other causes. A bone age is one test that is sometimes useful in confirming the "constitutional growth delay", it's a simple Xray of a wrist. If the bone age is younger than expected from actual age it fits the picture of someone who will have a later pubertal growth spurt. There is also screening blood work that can look for other causes. 

[Mommy22alyns]

I was never off the charts, and neither are my girls, but it looks like they're headed for a later puberty like me.  Rebecca's about to turn 12 and is 4'9", but she's unlikely to stay that tiny.  On size charts, she is always in the weight range for an 8 year old or so. But she's all muscle and very active, so I don't worry.  Saves a little money on clothes!  :D

[Catherine]

Genetics, genetics.

 

I have a child who was almost 10 pounds at birth, and remained long, and very (adorably!!) plump until he was about 3 1\2.  At 5, he remained tall, but was thin, and getting thinner.  

 

That child is 18 now.  He's 6'2" tall, very lean, and I suspect will stay that way.  My side of the family is inclined toward a tall, lean build.  My other two are not fat, but they are just more normally built, exactly like their father.  Broad shouldered, tending to plumpness in the belly.  

 

I think genetics is at play with your son, particularly given his gradual slide from "tall" to "short".  I wouldn't give it a second thought.

[MomtoCandJ]

Genetics- my girls haven't ever been over the 40th percentile. Dh and I are both under 5'4 and it seems some doctors don't understand that, we had to decline extensive testing for both girls (ordered by an urgent care doctor), we had the blessing of our primary to decline since she knows the short genes are prevalent in our families.

[Plateau Mama]

My Dr says as long as the growth curve is consistent there's no problem. So in your case as long as the trend down was consistent and he didn't go from being 95% for several years and then drop to 75 when he was 9, then all is good.

[maize]

I was never off the charts, and neither are my girls, but it looks like they're headed for a later puberty like me. Rebecca's about to turn 12 and is 4'9", but she's unlikely to stay that tiny. On size charts, she is always in the weight range for an 8 year old or so. But she's all muscle and very active, so I don't worry. Saves a little money on clothes! :D

My recent gymnastics reading brought up some studies about growth suppression in girls training intensively. Have you read that?

[Beaniemom]

The growth charts are so narrowly defined that they seem fairly pointless to me. I am 5'2" my dh is 6'3". My son sees and endocrinologist for growth/thyroid issues and she has felt out told me that with our height difference my dd's height is next to impossible to predict. As long as there are no drastic jumps in his curve she's content that he is doing well. DS is also one of those babies who had his own  weight curve below the chart which led to GI referrals and a nightmare of nonsense until I called a stop to it. No one seemed to want to hear that babies in my family tended to be small and I was very slight of stature/low weight until college. When dd came along later there wasn't the craziness when her weight slid off the chart because with ds's history they decided to wait and see if her own curve developed (which it did). 

[La Condessa]

Probably just genetics, but-- you said he has asthma. Is he on any maintenance medications for it? One side affect of an asthma medication my son was on was growth suppression. Apparently that side affect is almost always temporary, with kids still reaching the same adult height, just later.

 

It was Budesonide (Pulmicort).

[kiana]

The best, but rough guess of ultimate height for boys is to take Mom's height and add 6 inches. Then average that with Dad's height. Take the resulting number and that's the "mid-parental height". Two inches on either side of the mid-parental number is considered the "genetic potential". (For girls you take Dad's height and subtract 6 inches, average with Mom's and that's the mid-parental height.) So for a 5'2" Mom and a 5'10" Dad as an example... a boy would have the mid-parental height of 5'9", with expected utlimate adult heigh of 5'7"-5'11". A girl would have the mid-parental height of 5'3" with an ultimate expected height of 5'1"-5'5". Those are fairly big ranges and there will be people that fall above or below expected but it gives you an idea. You wouldn't expect a boy in the above example to be 6'3", nor would you expect him to be 5'3". 

 

(for the record -- this formula can be simplified to "Average the height of the parents. Then add 3 inches for a male child, subtract 3 inches for a female child" and will give the same results, without having to remember which parent you add or subtract inches). 

[Mommy22alyns]

My recent gymnastics reading brought up some studies about growth suppression in girls training intensively. Have you read that?

 

Yep!  I'm fine with that, and so is Rebecca.  She's constantly fretting that she might get "too tall" for gymnastics.  It will also likely delay her period arriving, which is good news to us!

 

There is also some evidence to suggest that growth spurts are quite possible after retirement.

[MysteryJen]

My recent gymnastics reading brought up some studies about growth suppression in girls training intensively. Have you read that?

I am on the fence about intensive training. My dd1 trained over 20 hours a week in two sports between the ages of 10 and 14. She was late to puberty, but her first period was only 6 months later than mine. She is taller than expected, but nearly a twin with her second cousin.

 

I think genetics play the starring role in growth and puberty.

[shawthorne44]

Could be genetics, could be a growth problem or could be not enough protein in his diet.  If puberty has started there isn't much you can do if it is a growth problem.   My DD is Growth Hormone Deficient so she gets HGH shots.  They don't work when puberty has started.  

 

I would work hard to get more protein into him. In a growing boy that certainly can't hurt.   Diet can have a big effect on final height. From studying the graves of Native American tribes, when a tribe went from hunter-gather to farming the average height dropped 6"-8".   

[wapiti]

.

[LizzyBee]

(for the record -- this formula can be simplified to "Average the height of the parents. Then add 3 inches for a male child, subtract 3 inches for a female child" and will give the same results, without having to remember which parent you add or subtract inches). 

 

That actually works in our family. Dh is 6'4" and I am 5'0". By your formula, our girls should be 5'5". All 3 of them are 5'5" to 5'6".

 

But in my birth family, my brother should be 5'7" and he is 6'. He was the shortest guy in his graduating class and had a big growth spurt after graduation.

[kiana]

That actually works in our family. Dh is 6'4" and I am 5'0". By your formula, our girls should be 5'5". All 3 of them are 5'5" to 5'6".

 

But in my birth family, my brother should be 5'7" and he is 6'. He was the shortest guy in his graduating class and had a big growth spurt after graduation.

 

This is actually Alice's formula (I just reformulated it to make it easier to calculate), and yes, of course, there will be outliers who are much taller or shorter than one would "expect". But for most people it will be a pretty good rule of thumb.

[Aelwydd]

I just wanted to say thank you to everyone who posted advice, thoughts, feedback.  Especially Alice, for sharing her perspective as a physician, herself.  

 

Basically, according to the ped, ds has begun exhibiting initial signs of  puberty (showing changes "down under"), although no facial or other body hair, no voice changes, that sort of thing.  He does stink, though.  Really bad after working out, lol.  

 

Ped thinks he will be short until 14 or so and then hit his growth spurt, maybe top out around 5'10" or so.  If that occurs, I would be just fine with that.  I have just been concerned that the fact ds has to be on inhaled corticosteroids year round here (thanks to Texas' environmental smelting pot of trees and grasses), that this may be stunting his growth.  

 

I don't expect him to be 6 feet tall or anything like that.  I am concerned if he is shorter than what he might have been, due to medication and/or really piss poor air quality in this area, that it will affect his opportunities later in sports, particularly as a hockey goalie.  We have no illusions about the NHL or anything like that, lol, but he would like to play Div II hockey in college.  Current trend is that taller goalies get picked over short goalies. :(

[catz]

I just wanted to say thank you to everyone who posted advice, thoughts, feedback.  Especially Alice, for sharing her perspective as a physician, herself.  

 

Basically, according to the ped, ds has begun exhibiting initial signs of  puberty (showing changes "down under"), although no facial or other body hair, no voice changes, that sort of thing.  He does stink, though.  Really bad after working out, lol.  

 

Ped thinks he will be short until 14 or so and then hit his growth spurt, maybe top out around 5'10" or so.  If that occurs, I would be just fine with that.  I have just been concerned that the fact ds has to be on inhaled corticosteroids year round here (thanks to Texas' environmental smelting pot of trees and grasses), that this may be stunting his growth.  

 

I don't expect him to be 6 feet tall or anything like that.  I am concerned if he is shorter than what he might have been, due to medication and/or really piss poor air quality in this area, that it will affect his opportunities later in sports, particularly as a hockey goalie.  We have no illusions about the NHL or anything like that, lol, but he would like to play Div II hockey in college.  Current trend is that taller goalies get picked over short goalies. :(

 

Is 5'10" really short for 2 below average parents though?  My 14 year old is 5'6" and may be shooting for 5'9"-5'10".  He was definitely on the top half of the growth chart as a toddler and came down.  Had a HUGE growth spurt at 13.  But is obviously still not a giant.  Anyway, I'm about 5'2.5", and my DH is about 5'10" (and definitely the tallest among his father and 2 brothers), so that's about what I was expecting at tallest for him.  My kid has is on no long term meds, has no chronic issues, eats everything.

[Aelwydd]

Is 5'10" really short for 2 below average parents though?  My 14 year old is 5'6" and may be shooting for 5'9"-5'10".  He was definitely on the top half of the growth chart as a toddler and came down.  Had a HUGE growth spurt at 13.  But is obviously still not a giant.  Anyway, I'm about 5'2.5", and my DH is about 5'10" (and definitely the tallest among his father and 2 brothers), so that's about what I was expecting at tallest for him.  My kid has is on no long term meds, has no chronic issues, eats everything.

 

 

Oh no, 5'10" is a good outcome for ds' genetic profile, IMO!  I am just concerned that environmental factors, such as asthmatic lungs (and the corticosteroids is on constantly), along with poor air quality, etc., may end up shorting him.  Literally and figuratively!  

 

I would be disappointed if I found out down the road that he missed his full genetic height due to perhaps addressable issues.  To this end, dh and I are seriously looking at moving to a different region of the country, where he could maybe have a break from allergens and not have to constantly be on medications.

[Deb in NZ]

I just wanted to say thank you to everyone who posted advice, thoughts, feedback.  Especially Alice, for sharing her perspective as a physician, herself.  

 

Basically, according to the ped, ds has begun exhibiting initial signs of  puberty (showing changes "down under"), although no facial or other body hair, no voice changes, that sort of thing.  He does stink, though.  Really bad after working out, lol.  

 

Ped thinks he will be short until 14 or so and then hit his growth spurt, maybe top out around 5'10" or so.  If that occurs, I would be just fine with that.  I have just been concerned that the fact ds has to be on inhaled corticosteroids year round here (thanks to Texas' environmental smelting pot of trees and grasses), that this may be stunting his growth.  

 

I don't expect him to be 6 feet tall or anything like that.  I am concerned if he is shorter than what he might have been, due to medication and/or really piss poor air quality in this area, that it will affect his opportunities later in sports, particularly as a hockey goalie.  We have no illusions about the NHL or anything like that, lol, but he would like to play Div II hockey in college.  Current trend is that taller goalies get picked over short goalies. :(

 

 

Neither of my boys began their growth spurts until after age 15.  Ds#1 has most likely finished his growth spurt, but at age 21 that is to be expected.  Ds#1 is only 5'5", but with dh only 5'8" at his tallest & me not quite 5', this is probably to be expected.  Ds#1's height has never held him back in work or sport.  What he lacks in size, he's more than made up for in strength.  

 

Ds#2 is still growing.  He's just now barely begun to need to shave (over a year older than ds#1 did) & his hands & feet are bigger than ds#1's.  Ds#2 is only 5'5" but has at least 5 more years of growth if he follows the same path as dh & ds#1.  He won't ever be 6', but is aiming for 5'9"+.  Ds#2 has played rep hockey for our provincial team since age 11 (as goalie since age 12.)  Last year he was named on the NZ U18 squad, one of the youngest to be named & definitely the youngest & smallest goalie.  Most goalies are much taller than ds#2.  What he lacks in size, he more than makes up for in speed, strength, agility, persistence, etc.  Ds#2's longer term goal is to play for NZ's national hockey team in the Olympics.  He knows that his size works against him, but this only makes him work harder, something that is definitely noticed by coaches & selectors.  At the moment he has more problems with his age as he is playing at a level above his age group & hockey politics are again holding him back.  

 

Size is only an issue if you let it become one.  I would think that your ds's asthma could be more of an issue for sport than his size.  

 

JMHO,

[Aelwydd]

 

Size is only an issue if you let it become one.  I would think that your ds's asthma could be more of an issue for sport than his size.  

 

JMHO,

 

I agree.  We live in a very hot and very dry climate.  Except when it's very hot and humid.  With lots of "orange" (high danger for asthmatics) ozone days during the summer.  Plus, we live near fracking wells, which bleed off benzene gas. 

 

Le sigh.

[MistyMountain]

I think it would be genetics. Not only do people all fall on different places percentile wise in adulthood but it happens at different rates and so childhood growth looks very different at different stages. Plus kids all hit puberty at different times and so some kids grow for longer then others and end up taller then expected. The reverse is also true. With parents shorter then average going down in percentiles slowly over time doesn't sound to worrying. Two of my babies and toddlers were in bigger percentiles then they were as they got older.

[kiwik]

NZ has a high asthma rate meaning a lot of our sportspeople are asthmatic. It is possible to win olympic medals with asthma. Ds7 has always been tall but I doubt he will end up tall. His dad is 5 10 and I am 5 4 so I expect he will be about 5 10. His dad had puberty early and was mature enough that his classmates sent him to buy alcohol for them at 13 or 14 so I expect ds7 to be tall until then and then get overtaken.