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 often....you 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 positive....it 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.