The Number Field

Elena had her one year checkup on Friday. She soldiered through five shots; the worst part for her wasn't the needle sticks, it was being restrained for long enough to get them all done. Our doctor was still impressed by Elena's good nature and willingness to undergo examination. But the biggest news of the visit was Elena's current weight.

She's still close to the ninetieth percentile for height, which is not much of a change from before. But her weight has jumped way above all the lines on the growth charts. She's now 28 pounds, 13 ounces. At that weight, percentiles don't begin to tell the story. I've done some calculations that put things into perspective. If she were to weigh exactly the same amount in six months, she would still be in the 95 ^th percentile; in one year, she would be in the 75 ^th percentile. Each year in the United States there are only about 60 girls who weigh that much or more at their first birthday. *

It's such a high weight that, when considered together with her large tongue, the doctor has referred us to a geneticist. She doesn't think that there's anything wrong, but thinks we should check things out more thoroughly just to be sure.

Elena has always been a good eater, but we've tried to feed her healthy things, mostly oatmeal, fruits, and vegetables. Despite the video and picture below, we're glad that we can't attribute her high weight to unhealthy eating. But for her birthday, she deserved cake and ice cream, so that's what she got!

* I assumed that infant weight is normally distributed and used a growth chart to estimate the standard deviation and Elena's z-score. I then multiplied that by about 2,050,000, which is an estimate for the yearly births of girls in the United States.