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I'm here with Dr. Laura Bachrack at Stanford Medical School

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and what are we going to talk about?

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We are going to talk about normal and abnormal growth in children

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Fascinating...so, this is an important concern...

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Parents really worry if their child is growing normally

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and physicians worry about this too because

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the change in height is an important barometer

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of how the child is doing overall in terms of health

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Right...so to begin to assess the child's growth pattern

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we have to think about what are the determinants

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of where the child should be on the growth curve

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Right...the number one most important determinant,

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of course, is genetics. Short parents are more

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likely to have short children and vice versa

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And that's also true even when the child is young

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if...like...big, cause sometimes I've seen in the opposite

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so, you know....people who are petite have large children

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and all the rest but it is true even if someone is large or

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someone is large they're more like to have large children

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even in infants and toddlers...

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You have hit upon a really important issue that is

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shown here in the slide.. the size of a baby at birth

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isn't necessarily going to reflect the genetics

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There are babies that are born small because the mother

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didn't have pre-natal care...mother was a smoker...

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other factors that compromised the growth of the child

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and those can be born small for their gestational age.

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During the first two to three years of life, they have

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a chance to catch up on the curve and reach what's

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called their genetic potential. So let's say...

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So, I want to make sure...I have seen these curves before...

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I remember this when I used to visit the Paediatrician

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which I did, may be a little too long, but eh, so

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so this axis right over here is age, in months

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In months...so this is right here at birth. So if a baby

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born at, I don't know, uh, this is the weight right over here

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So if the baby are born at 5 pounds,

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is this in pounds, this is in kilograms. So 5 pounds is

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right over here. So this would be a baby born at 5 pounds.

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And I'm talking more here during this growth lecture about

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the height or the length of the baby

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throughout childhood, but let say

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the baby were born light in weight and short in length

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So maybe 18 inches here would be a short length.

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And let's say that that baby were small because

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his mother had issues during pregnancy.

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Is it always the case that the baby would be small because of issues or i mean...

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No...the bottom line is the genetics

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plays less of a part in the size of the baby at birth

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and it will later on in childhood.

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So it comes back to your point. You'll meet parents whose baby seemed

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a bit larger or smaller than they are.

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But by age 3, the child should be...

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Hold on 1 second, let me just

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close this...OK.

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By age 3, the child should be in his or her genetic group if you will.

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So, there can be movement on the growth curve in the first 2 to 3 years

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of life. There can be catch up growth where the child who were small

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let's say moves from below the curve up to the 50%

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by age 24 months. And you could have the convert.

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Where you have a very big baby, let's say the mother had uncontrolled diabetes

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and the baby was born very large, that baby can have catch down growth

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to the 50%. By the age of 3, certainly movement across percentile

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is considered to be abnormal and warrants an investigation.

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So you really can predict someones even adult height based on where they are at 3?

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The general rule of thumb is that by the age of 2 and a half to 3 the child is in their genetic

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growth. Really? Mhmmm... Wow..I didn't realize that that quickly you can kinda..

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So if a child in age of 3 or 4 is in the 25% of height, it is unlikely

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that they are gonna be in the NBA.

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In general that's true there's a few exception there are late group of bloomers

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what we call a constitutional delay of growth

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but the general rule would be what percentile you are by the age of 2 or 3

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is pretty much where you're gonna track if all things are going normally.

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Wow..I never realize that's ahh...that's ahhh..

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In genetics, it's an important determinant as they said. we can actually do a calculation

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of where we think the child should end up the so called mid-parental height

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I wish we're gonna talk about it later.

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So, genetics is a critical factor but whether or not you reach your genetic potential

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means that the cards have to be lined up appropriately.

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So the cards that are important for achieving your genetic potentials

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first of all, number one, normal amounts of hormones that are important for growing.

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And those are thyroid and growth hormone to a large extent.

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The second factor of course is adequate nutrition and we think worldwide of children

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who are under nourished who don't look anywhere near their age in terms of height

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because they're so under nourished.

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And you see the reverse of that, I mean I was born here and my parents were the 1st or 2nd generation..

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we see that people in my generation are much taller that their parents because their parents

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were probably malnourished in some way.

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Certainly there can be a secular trend where the children get taller than their parents

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if the children have a different environment. The other thing that we notice about

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nutrition in our country is the over nutrition of our children and what happens

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with obesity is that children may grow faster, in terms of weight and height for their age..

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they don't end up taller in the long run but they move ahead more quickly through the maturation process

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I see...like they accelerate. Exactly.

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I never realized that. That's fascinating.

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And then we think about psycho social factors, there literally a situation where

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infants can be deprived of parental love and support and you can see

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some dwarfing there. In a teenager we see problems with eating disorder

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that's a cross between nutrition and a psychological problem.

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It a psycho social factors.

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So it's been seen that it's a noticeable changes in physical development based on

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attention in love and....

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Yes, there's actually a syndrome called Psycho Social Dwarfism

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where you actually see them slow down in growing without adequate interpersonal support.

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So, the issue is when do you need to worry about a child's growth pattern.

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In order to interpret that you really have to understand about the variability in growth.

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In the first 2 to 3 years of life children grow much more quickly than they will later on..

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By the age of three, until they hit puberty, children should grow 2 inches a year.

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This is out of the toddler hood until they hit puberty.

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Wow, so this is like the tree of puberty. Exactly, exactly.

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But when kids will hit puberty is going to be very long...

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and so that's an issue. If the children are growing at a normal rate

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it's not necessary to memorize the inches per year

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Children will track along the growth curve and if we could turn to the next

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slide or graph. This is the graph that we use for older children.

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After the age of 2 up until they're 18. This is the curve that we use.

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Now, beyond the age of 2, I told it is not normal for the children to

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necessarily cross percentiles. So if for example you have a child

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who is tracking along the 5th percentile every year growing their 2 inches per year...

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They're moving along steadily, steadily, steadily...

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that child has a more reassuring growth curve than one for example

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who as a 5 year old had been on the top of the curve

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and then the next year is on the 75th moving down the line

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and the year after is on the 50th percentile.

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Now that point in time the child has theoretically a normal height

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because its within the curve, but there's something very abnormal

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about that rate of growing and that's the child is more worrisome than the shorter child.

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I see...fascinating.

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So bottom line when a child would come in to present to me because of the concern

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about growing, I first of all try to decide if they're short and if they're growing normally.

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And those are 2 different questions.

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The 1st question is are they short? And are they short can be defined by looking

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at these curves. These are curves representing the spectrum of normal height

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for healthy American youth. And they go from the 5th to the 95th percentile.

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So you can compare a child to the population as a whole

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but I also like to calculate what we call the mid-parental height.

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This is where we take into account the heights of the parents.

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Because that's the most important determinant.

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So how we calculate that is as follows.

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We take the height of mom and dad and average them.

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OK, let's do that.

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So, I'm 5"9 if I'm wearing decent shoes.

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And how tall is the mother of your children?

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She's 5"6.

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And are we trying to calculate your son or your daughter?

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Let's do my son since he's little older, so he is plus 66 inches.

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So we'd take the mid-point of that and we're gonna add 2 and a half inches.

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OK, so that gets us exactly 70 inches.

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Right, so that's the height prediction for your son.

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Oh, very good.

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Plus or minus...4 inches.

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Oh, plus or minus 4 inches, that's a big difference.

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It's a big difference but that's the nature of human variability.

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OK, if these were your daughter, we would take the 67.5 inches and subtract 2 and a half inches.

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Let's do that.

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OK, so she would get 65...plus or minus 4 inches.

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So that's something we do. We then calculate, in fact let's plot that

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right on the curve, this is the boy's curve. So let's plot the 70 inches.

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70 inches is right over here, OK.

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And then the range of 74 to 66.

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Pretty broad range. OK, but if we had a child who is growing well below the curve

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and we thought that mid-point she'd be about the 50th percentile,

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that child would be short for the family.

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So we always like to take the family's height into account.

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So, number 1 question is the child short?

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It will depend on what the height prediction is.

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I see. So if my son was tracking down here at the 5%...that would be concerning.

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Even if he's growing the 2 inches every year, it would still be concerning?

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Well, it would raise some questions in our mind.

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But more important factor is not just where they are on the curve at the moment,

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but are they growing at the normal rate.

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And the child who is not growing at the normal rate raise more red flags

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than the child who is trotting up the curve.

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Fascinating, it's interesting. Wow!

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So that's the issue and that's what we approach every day

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we want to look into the various causes, potentially for a growth slowdown

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we want to adjust treatment to the specific ideology

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And ideology means....?

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Well for example, if the child has a deficiency of thyroid hormone, we'd want

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to give the thyroid hormone back.

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So ideology is like the cause of the...right, right, right..

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So if the child isn't growing because he has a nutritional problem like Celiac disease,

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we want to put him on a special diet to address that issue.

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Some parents think, well, what we wanna do..my child is healthy and normal and growing normally

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but I wanna give him growth hormone, that becomes a topic in itself.

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Well, thank you for this. This is super informative.