Your child’s head is probably normal

Asks Boegiboe:

 Are infant and toddler size-weight percentiles useful things for parents to be looking at, as opposed to just aggregations of data for physicians to use?

The latter.  Dear God, the latter.

Weight, height and head circumference percentiles are similar to developmental milestones in their utility.  They are useful for medical providers to track growth over time, and to detect abnormalities.  They are not useful as snapshots, and they are not worthwhile as a point of parental fixation.

Sometimes they are helpful visual aids when I am trying to help parents grasp the significance of a problem they may be denying.  If a child’s weight is soaring off the top of the chart or plunging through the bottom, showing the parents the curve can facilitate communication.  But in almost all cases, the problem is visible to the naked eye anyhow.  If the kid looks basically proportional and well-nourished, then chances are very good that his height and weight are fine.

The same is true of head circumference.  If your child’s head looks normal as compared to the rest of her, it almost certainly is normal.  Where it falls at any given time on the growth curve is probably not important.  The growth chart can be useful if the head is growing much faster or slower than height and weight, but it’s not something I would encourage parents to worry about.

But parents always want to know their child’s percentages, and often evince anxiety when their child is a little bit higher or lower on the curve than seems normal.  In these situations I advise them to believe their eyes, and be reassured by their child’s healthy appearance.  I tell them (as is almost always true in almost all situations) that if their child seems fine, he or she probably is.  If it’s a chart vs. their own sense (and mine), their sense is almost certainly right.  Growth charts are helpful in detecting those rare occasions when things aren’t all right, but it’s my job to pay attention to these things, not parents’.

Russell Saunders

Russell Saunders is the ridiculously flimsy pseudonym of a pediatrician in New England. He has a husband, three sons, daughter, cat and dog, though not in that order. He enjoys reading, running and cooking. He can be contacted at blindeddoc using his Gmail account. Twitter types can follow him @russellsaunder1.


  1. Coming from the man who did not birth my 10 pound baby. His head is huge and I will not have you deny it!

  2. “In these situations I advise them to believe their eyes, and be reassured by their child’s healthy appearance.”

    This. A bazillion times.

    We have had a number of health care workers (doctors, nurses, etc.) who were so absulutely consumed by numbers and chart placement for our eldest daughter. Not only was it never helpful when there was a legitimate concern (there were some eating issues that we had to work through at various times), it just added unnecessary stress – even when there was no problem. Unnecessary stress, as you might imagine, is never a helpful prescription from a medical professional.

  3. when my son was born, his head was so big they had to cut apart a leg wrap and tape one end closed for a hat. he’s normal and healthy, just always been very large for his age.

  4. Our kid B and my friend’s kid N were born five weeks apart. N has always hugged the bottom of the chart on head-size; B has consistently been around the 3-z-values-above-mean line. They are similar in height and weight.

    Each of them, looked at individually, looks fine. But when we take them to the park together and take a picture sitting right beside one another it looks like SOMEBODY got photoshopped. It’s hilarious. And very normal. :->

    (note: my preschooler’s head is .5in smaller than mine)

  5. Fortunately, when we were brand new parents we had terrible bouts of colic induced sleep deprivation to distract us from worrying about the size of our sin’s melon.

    • I’ve had parents say to me that they’re worried about how small their kid’s head is, then tell me it’s 25th percentile. So I think it definitely freaks people out. It doesn’t help that we always get a sheet a paper with the measurements on it, which communicates it’s important enough for us to keep records, too.

      Also, every nurse who measures has her own quirks. A relatively tiny difference in where the tape measure is placed for head circumference can come out drastically different percentile-wise. One day, we will be informed that my special needs kid officially has microcephaly, the following week he will be 10-25th percentile. Two different nurses can get heights that are off by two inches within a week of each other.

      There needs to be a position paper or something put out about what to do with small kids. My oldest was born at normal weight, but has been at 3-5th percentile in height and weight ever since he was three months old. He looks perfectly healthy and proportioned and has plenty of energy. He’s just tiny. He eats everything and anything, he just never wants to eat very much. We have had some pediatricians tell us to try to stuff him with pediasure. Another urged us to visit a nutritionist. Our current ones are not worried in the slightest. It seems worth noting to us, and to some doctors, that my husband is quite short and was a skinny kid. But other docs panic.

      • My son was large at birth, 90+ percentile in height until he was about three (people assumed he and his two-years-older sister were twins), at which point his growth slowed way down, and he was always the shortest boy in his class until high school, when he started to catch up. Now he’s 17, almost as tall as I am, and will probably wind up slightly taller. Fortunately, we never had a pediatrician who was prone to panic about the fact that kids’ growth patterns are all different.

    • Was your “sin” conceived outside the bonds of matrimony?

  6. If you’re taking medical questions, I have one: Why does my antihistamine (cetirizine) give a single recommended dosage for adults and children ages six and up? How can the same dose be appropriate for both a fifty-pound child and a 200-pound adult?

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