Future linebacker in the making?

May 29, 2010 5:43 AM

Will my big baby be a big adult? He 9 months and is in the 80th+ percentile for height and weight and his head is (literally) off the charts big. I am just kind of curious as to whether he is likely to be super tall/big as an adult and my googling of this question has let me down.

He was born average sized (6pounds, 12 oz) but he is now really big for his age. I am 5'8" with a thin build and dad is 6' and average build. I assume he will be somewhat tall based on my height. But he seems so big when I see other kids his size running around and chewing meat since they are so much older than my crawling, baby food eating son.

I am not worried at all about his eventual size but just curious if any of you had big babies and how they turned out size-wise.

posted by murrey to grab bag (31 answers total)

Every child seems really big for their age, because people keep getting bigger, and the distribution he's being compared with will be of children who were children many years ago.

(or so I understand from my be-childrened sisters, whose kids have grown up to be about the right size...)
posted by pompomtom at 5:55 AM on May 29, 2010 [1 favorite]

My little brother was 10 pounds at birth, and remained in a very high percentile until he was about 3. We even wrote a song about how fat he was. He's seventeen now, and about 5'10" and 150 - right in line to be about 6'1" and 170-80, like his brothers.

We still sing the song, though. We put a lot of work into that.

We were all pretty massive babies, but skinny children. Blame it on the breastfeeding. (By the way, if you're breastfeeding him, make sure that they're looking at the breastfeeding height/weight charts - they're different for formula-fed and breastfed babies.
posted by punchtothehead at 6:00 AM on May 29, 2010 [4 favorites]

Our pediatrician told us there is almost no correlation between the size of the baby and the size of the adult. We all grow at different rates, that's all.
posted by ook at 6:00 AM on May 29, 2010

You can, at age 2, pretty accurately estimate adult height by doubling it. There's another, slightly more complex formula here. As far as I know, there isn't an established correlation between infant height/length and adult height.

Height is a multifactorial genetic trait, so it's hard to predict based on either parent. Example: my mother is 5'2", but everyone else in her family is 6' tall. My father is 5'8". I was a super-long baby, and my hands and feet were huge for my childhood AND my adult height - I'm 5'3", and I can palm a regulation basketball.
posted by honeybee413 at 6:10 AM on May 29, 2010 [3 favorites]

just curious if any of you had big babies and how they turned out size-wise.

Or if any of us were big babies and how we turned out? Everyone talked about how "big" I was when I was a baby: 9 lbs. 7 oz. and 22 inches. At 29 years old, I'm about average size, not particularly big: 5'10" and around 150-160 lbs.
posted by Jaltcoh at 6:27 AM on May 29, 2010

Generally they say the child will USUALLY fall somewhere between the mother's and father's heights, assuming neither mom nor dad was malnourished or had a growth problem. If mom and dad are close in height, the kid gets a bit more range outside their heights for the "standard" prediction.

My parents are 5'7" and 6'0" ... I ended up 5'2". My 3 siblings are all over 5'10", with one brother around 6'2" or so. I just got screwed.

My one-year-old was born rather small but then grew SUPERFAST (so fast I was sure I was going to die from the breastfeeding demands!) as a newborn, almost twice the average rate of growth, and then leveled off and let the other babies catch up. The doctor says it's just hard to say whether he'll end up tall like his dad (6'4"), short like me, or split the difference. Some of my friends' kids grow nice and steady; my baby seems to grow entirely in spurts. Just when I start to get paranoid he's stopped growing, he gets huge overnight. (I'm trying very hard not to worry about it but as you can see, not succeeding well!)
posted by Eyebrows McGee at 6:32 AM on May 29, 2010

Our pediatrician also told us that babies grow at different rates, and that percentiles are good predictors of adult size only after about the 2yo mark.
posted by about_time at 6:40 AM on May 29, 2010

2nding that he just seems big.

My kid was 99th percentile for everything until he was 1 and now he's been 99th for height and HC and 70th-ish for weight (I'd bet on people feeding kids junk.) Yet we know kids that are also 99th that are 18 months and the size of 4 year olds.

But more importantly, once they start crawling and walking, the growth slows way way down.
posted by k8t at 6:40 AM on May 29, 2010

Kids move around a lot on the charts and growth is pretty irregular. The percentiles are used to watch for growth problems and aren't terribly consistent even from one check-up to the next, much less to adulthood. My kids were enormous babies/toddlers (not at birth, but soon after) frequently with 80th/90th percentile on the charts, but are turning into pretty normally sized, only slightly taller than average older kids. At nine months, it's to early to tell much. When he starts walking and eating more regular food, things will change quite a bit. By about age two or three you'll have a better idea of his general body type.

My eldest was so fat as a baby that we had to actually pull back her arm-fat to wash her wrists, but she's a pretty thin seven-year-old. On the other hand, my kids were all also off the charts or at the tippy-top for head circumference and that hasn't changed. My five-year-old's head is bigger than many adults, but he's very skinny (like a watermelon on a toothpick), so a big head isn't indicative of a big body.
posted by Dojie at 7:02 AM on May 29, 2010

Here's a page that discusses growth charts and adult size a bit.
posted by Dojie at 7:10 AM on May 29, 2010

Generally they say the child will USUALLY fall somewhere between the mother's and father's heights,

That seems implausible. Since men tend to be significantly taller than women, wouldn't that mean that the male population is shrinking while the female population is growing?
posted by Jaltcoh at 7:12 AM on May 29, 2010

There's no correlation between infant size, toddler size and adult size. I was 22" at birth, and at age 2 my pediatrician happily predicted I would reach 5'6" or 5'7" as my adult height based on my toddler height and the length of my femurs. I was the tallest girl in my preschool class...

...and the smallest girl in my kindergarten class, topping at out age 20 with a height of 5'2" (I grew an inch after I turned 18, thankfully). And that's kind of generous, I might be overestimating by a quarter inch or so.

I still have unusually long femurs and a huge head. Stupid, lying femurs.
posted by annathea at 7:15 AM on May 29, 2010

Darn, sent too soon - I should mention that I am two inches shorter than my mother, who is my shortest parent. My half-sister, whose mother is 5'8" (our father is about 5'6") is 4'11". So I don't think the child's height typically falls in between those of the parents, either. Our baby sister is taller than both of her parents at 5'9".
posted by annathea at 7:17 AM on May 29, 2010

"Since men tend to be significantly taller than women, wouldn't that mean that the male population is shrinking while the female population is growing?"

As noted, there are a couple of assumptions built in -- first, that everyone is well-nourished (a lot of average-height-growth over the last century in first-world countries has been due to increased adequate nourishment); and second, if the mother and father are close in height, the child's "range" goes farther outside their two heights. If they're distant in height, the child's "range" is more likely to be in between the two.

But it's just another way of guesstimating. None of these methods are particularly accurate.

It is, however, unusual for two very short parents to have a very tall child, or vice versa (assuming adequate nutrition and no illnesses/disorders). Parental height does correlate to child height at least to some degree. Whether that means the average population is shrinking or growing I couldn't tell you. :)
posted by Eyebrows McGee at 7:31 AM on May 29, 2010

I entered the world above the 99th centile and stayed there ever since. What everyone else says about variability is true, but it's certainly possible that he'll be a big guy. Though I would say that in my family being merely over the 80th centile is not 'big' - you have to get over that 99th to be 'big'!
posted by Coobeastie at 7:42 AM on May 29, 2010 [1 favorite]

I was a big, fat toddler, and starting at age 4ish was skinny and have been tiny (short and skinny) ever since.
posted by ishotjr at 7:42 AM on May 29, 2010

I was a tiny, tiny baby, a tiny, tiny toddler, a tiny, tiny child, and a fairly small adult. When I was a baby, the doctor told my parents I would probably not be taller than 5 feet. When I was 2, I was off-the-charts small and they x-rayed my wrist to see if I was possibly a midget or a dwarf. I wasn't. I was a head shorter than everyone in my class until about 4th grade, when I became just a bit shorter. By high school I was 5'2 and 100lbs and for the most part I have stayed that way until today.

So sometimes baby size is correlative. But I imagine it is not always.
posted by millipede at 7:50 AM on May 29, 2010

As noted, there are a couple of assumptions built in -- first, that everyone is well-nourished (a lot of average-height-growth over the last century in first-world countries has been due to increased adequate nourishment); and second, if the mother and father are close in height, the child's "range" goes farther outside their two heights. If they're distant in height, the child's "range" is more likely to be in between the two.

I'm not following you. For instance, let's say there's a couple who are both about average height for their gender: a 5'5" woman and a 5'10" man. Let's say they have a boy. I don't understand how you can say the boy will more often than not grow up to be between 5'5" and 5'10". More likely, he'll be around 5'10" since he's male. He might be between 5'5" and 5'10", of course, but isn't he more likely to be, say, 5'11" or 6'0" (not within the parents' range) than 5'5" or 5'6" (within the parents' range)? I just don't see how the range between the mother and father's heights is relevant at all, considering the sexual dimorphism involved.
posted by Jaltcoh at 7:52 AM on May 29, 2010

My baby boy was fat - really fat. He's seven now, so I don't have the full picture yet, but somewhere around two, the pounds started to fall off. He's tall - in the 98th percentile, and his pants to fit his height fall off his slim little hips. The doctor says he's healthy, and that of course, there's nothing wrong with being tall. As long as he eats, everything is good. He doesn't always eat, though; that's a fight.
posted by mitzyjalapeno at 8:17 AM on May 29, 2010

Those baby percentiles, I've always assumed, included a lot of poor kids who weren't ideally nourished, kinda clouding the numbers for the sort of parents who have the time to obsess about these things. We had big, fat babies, and got lots of comments. Now we have very tall, thin kids and we're average (5'8", 5'11"). I think nutrition might have a lot do with it. It's a big focus with us.

Big heads: being of Irish descent, I had a Peanuts-scaled noggin. Our town doctor had to inform a new-to-New England doctor that some of the newborns the new guy was concerned had infant Encephalitis merely had Mc- and O' surnames.
posted by bendybendy at 8:36 AM on May 29, 2010

@Jaltcoh -- I don't mean to derail this thread entirely, and I apologize that it seems to be coming to that.

The Khamis-Roche Method, which is what my pede was using (I had this discussion just this week at the 1-year checkup), uses the child's size and gender as well as the height of each parent to estimate the child's adult size. It's been in use since 1994 and the researchers claim it gets within an inch and a half of adult size for most children. You can find calculators for it online if you're super-curious, as well as published papers about the method. Slightly older methods, that average the parents' heights and then add X inches (usually 2 or 3) for a boy and subtract X inches for a girl, that don't take into account the child's size, can be as much as 6 inches off. My pede told us that research shows that MOST children are between their parents' heights, assuming everyone's fully nourished and have no complicating medical factors.
posted by Eyebrows McGee at 8:36 AM on May 29, 2010

Those baby percentiles, I've always assumed, included a lot of poor kids who weren't ideally nourished, kinda clouding the numbers for the sort of parents who have the time to obsess about these things.

There's just a lot of variation, too -- the flip side of this is that they include kids who were absolutely ginormous at birth, while smaller newborns will obviously take some time to close the gap.
posted by redfoxtail at 8:42 AM on May 29, 2010

Here's a calculator you could try, based on the Khamis-Roche method.

Going by the CDC growth charts, if your baby continues to grow at the 80th percentile—which is far from certain—his adult height will be about six feet, which is a nice, normal height. Tall, but not tall enough for people to ask annoying questions about it.

The growth charts certainly do not work for everybody, but they've worked for us. For our two kids, there's a pretty close correlation between infant size, toddler size, and teen size. When they were preschoolers, the charts predicted my younger son would pass my older son in height when they were 12 and 16, and so he did. He's always been above the 97th percentile for height, and looks like he's going to continue; he's almost 5'11" at age 13. He eats constantly and is on the slim side. He was always a big baby, even at birth, and I am short myself, at 5'3", so pregnancy with him was a real challenge.
posted by Ery at 9:51 AM on May 29, 2010

My daughter was always between the 80th and 99th percentiles in the first year and a half.

She's 10 now and very slim, short in her class, slightly below average. (Her dad is 5'4", I'm 5'5".)

A millionthing the "you have no way of knowing".
posted by Gucky at 10:51 AM on May 29, 2010

My ex was incredibly tall for her age group until Junior High and is now 5'9" or so as an adult.

I was 11 pounds at birth and stayed 99th percentile for as long as my parents were tracking. As an adult, I'm 6'5" and heavily built. I'm taller and bigger than both my parents, but have a similar height and build to my grandfather and several male relatives on his side. I also had a really big head, which I'm told required me being pulled out with clamps. I still have a big head, but my wisdom teeth came in with room to spare and I get to keep them, so bonus.

Just adding to the "you can't really know" and "80th percentile is not going to be freakishly large" chorus.
posted by Derive the Hamiltonian of... at 11:13 AM on May 29, 2010

I was a big baby, but also a very long (ie tall) baby; my mother's nickname for me was string bean. My dad is 6'2" and I was the tallest kid in my class for years and years and fucking shagging annoying years. And then when I reached the epic hight of 5'4", I just... stopped growing. That was it, I'd reached my full height, just a lot earlier than my classmates.

I appear to have shrunk since then, and I am now officially a short-arse.

I have a friend, however, who's child was so large for her age it did cause some issues, mostly because people assumed she was several years older than she was and in shops, etc, expected her behaviour to be in line with her presumed age, not her actual age. A tantrum that's tolerable in a four year old raises a lot of eyebrows in a six year old, you know?
posted by DarlingBri at 11:54 AM on May 29, 2010

I was average birth weight, and an enormously giant fat baby. My baby pictures look like someone dressed up a cartoon ham in baby clothes. I'm about 5'2" and have never weighed over 115lbs, so clearly YMMV.
posted by elizardbits at 11:59 AM on May 29, 2010

I was the tallest kid until 5th grade, then everyone overtook me.
posted by meepmeow at 1:07 PM on May 29, 2010

My child was consistently at the top of the growth chart, from birth. At the age of two I predicted that he would be 6 feet tall at the age of 14. With four months to go he is one inch shy of that. You should not try to predict his ultimate height until you have four or more data points that are in the same general area. As far as head size, let's just hope that it becomes more normal with time.
posted by Midnight Skulker at 1:37 PM on May 29, 2010

There are moderate correlations between a mother's height and her baby's birthweight, and significant correlations between the heights of parents and their children. There are also big differences between the birthweights of boys and girls, and big differences in eventual height. So at a population level big babies are more likely to be big adults. However on a family by family basis I think it's too early to say if your son will be big, at least relative to any other boy of your ethnicity.
posted by roofus at 12:05 AM on May 30, 2010

I was one of 5 kids. My mom's largest baby turned out to be the shortest of us. Her smallest baby turned out to be the 2nd shortest.

Hubby's one of 4 kids. His mom's largest baby and his mom's tiny preemie are both significantly shorter than the other 2.

From those four data points it looks to me like infant size doesn't have much to do with adult size.
posted by galadriel at 3:55 PM on May 30, 2010