Monday, August 6, 2012

Growth charts and tiny babies

This is another post that reflects my current life situation, but it highlighted some pretty interesting issues with data tables.

This issue is particularly interesting to me because I delivered via unplanned/urgent c-section, in part because of some abnormal measurements found during a routine ultrasound.  We had to have quite a few follow up consults and testing (among other things, they actually had to assess for achondroplasia - better known as the major cause of dwarfism)*.

Given this, my mother thought I'd find this Wall Street Journal article on baby growth charts interesting.  Essentially, baby growth charts were set several decades ago based on a population that's different from what we have now.  The CDC does not want to readjust the charts, as it would make obesity look more normal than they think it should, and this is causing a situation where a high number of children are measuring "off the charts".

It's an interesting situation when you realize that 95th percentile doesn't actually mean "larger than 95% of children of the same age" but rather "larger than 95% of children the same age 40 years ago".

Additionally, it also points out that the CDC growth chart is based largely on formula fed babies, who grow slightly differently from breast fed babies.  So at the same time Mayor Bloomberg is pushing breastfeeding, doctors are potentially telling parents their children need formula to speed their growth up to match a chart that only tracks where they would be if they had done formula to begin with (this is why state mandated health policy drives me nuts so solve one aspect while leaving several causes unadressed).

As the availability of testing goes up, we have to be particularly vigilant to make sure our standards charts keep up as well.  Otherwise we routinize unnecessary testing and freak out new parents.  And from personal experience, I can say that's just not nice.

*It was ruled unlikely, though apparently we can't get a definitive no until he actually starts growing, or not as the case may be.  There's no genetic history of it in my family or the husband's, though we are both on the short side.  In this case, us being short is actually a means the abnormalities are more likely natural variations.  Our genetic consult doctor was hilariously terrible though....she suggested if we wanted more information about the condition we watch the reality TV show about it (Little People Big World).  Then she said it was unlikely, but maybe we should still watch the show.  She ended it all with a comment about how it was never good when genetics doctors had too much to say, so we should be happy she wasn't talking too much.  I don't think she was very self aware.  


  1. Oh, geeze. It appears you are being tortured a bit.

    Just relax and enjoy Finn. Does he suck well?

    1. Well, it's a little less stressful than one would think, given that the primary reason for early delivery was a suspicion of abnormal head growth/brain swelling. When the first conversation revolves around brain tumors and hydrocephalis, anything else feels totally manageable.

      In every other sense though, he's a fantastic baby. Feeds like a champion, impresses every doctor with his alertness and reflexes, cries only when there's a clear problem. I'm awfully fond of him already.

  2. Congrats! Parenthood is a crazy, amazing ride!

    Andrew was always off the CDC charts. Personally, I always consulted the WHO charts, which although based on a smaller pool of babies (I think), based their percentages on breast-fed babies (who gain weight slower & steadier than formula fed babies). Again, the oxymoronic logic: stop childhood obesity! You're baby doesn't have rolls of skin hiding its features...supplement formula! Andrew is short and was still down in the 5 or 10% range for at least the first 8 or 9 months of life. I had to switch to partial formula at that point thanks to a 3 month bout of thrush we shared, and he gained weight quite rapidly at that point. His extreme activeness kept him from chunking out too much, thankfully. And now at a year he's perfectly average in every way. But all those months I just kept smiling at the doctors and nurses and telling them, "Well, someone has to be at the bottom, hmm?" We have enough avenues to push overachievement on him in the future; we decided to skip this one.

    Best of luck. I found insane amounts of education, a good sense of not taking things personally, and a firm stance on our nonnegotiable helpful in navigating the doctors. It's amazing how quick your protective Momma Bear instincts come out!