Sunday, January 27, 2008

Testing

I had a round of testing yesterday, which included the initial glucose screening. As I understand it, this screening is a bit easier and more pleasant than the more serious glucose tolerance test. It involved drinking 10oz of, basically, really bad orange soda, on an almost empty stomach, waiting around for an hour, then having blood drawn. I had to have blood drawn for many, many other tests yesterday as well, so they ended up taking 12 vials (yes, that's right, an even dozen). Other than when I've donated blood (which involved lounging on a couch with my feet up, then being fed ice cream, as opposed to yesterday, which involved an uncomfortable chair that I was immediately thrown out of and sent on my way) I don't think that I've ever given up that much blood at once. There was also the uncomfortable several minutes when the tech refused to draw blood for several of the tests that Dr. M. requested, because she wasn't sure what the tests were, and didn't want to bother finding out.

Tech: "I don't know what this says."
Me: "It says 'Tay-Sachs mutation carrier.'"
Tech: "I don't know what that is, so I'm not going to do it."
Me: "It's a fairly common genetic test. Can't you just draw blood for it and look it up later?"
Tech: "Um... nah. I think instead we just won't do it."
Me: "But, I really need it done, and my doctor requested it."
Tech: "I doubt that, because I've never heard of it."
Me: stunned disbelief....

I argued with her a bit more, and one of the other techs eventually came over to see what was going on, and went and looked it up and told her that he would run the tests for her. The tests in question are a series of 4 genetic tests that Dr. M. ordered, because my Ashkenazi background puts me in a high risk group. Now, I realize that there aren't a whole lot of Jews living in this area (that is certainly not news to me) but seriously? You're a blood tech and you haven't heard of the genetic screening for Tay-Sachs? I'm not the only Jewish woman around here! (Though honestly, the whole thing is probably moot. S. is not of Ashkenazi descent, and for all of the things I was tested for, S. and I would both have to be carriers for my carrier status to matter at all, so the odds are incredibly slim. Not to mention, if anyone in my family were a carrier, I would think that I would have heard about it by now.)

Anyway, this round of testing is done. The only thing that I'm worried about at all is the glucose test, because damn, getting gestational diabetes this early in the pregnancy would suck. As would having to take the tolerance test as a follow-up, since it involves true fasting before hand, twice as much bad orange soda, and several additional blood draws over the course of 3 hours of sitting around the lab. Just what a nauseous woman wants!

Also on the topic of testing... we need to decide by our next appointment what screening tests we want to do (eg, triple screen and the high-resolution ultrasound for Downs, Trisomy 18, etc.). S's view: these tests have zero risk associated with them (an ultrasound and a blood draw), and they give us information, so we should just do them. My view: the tests themselves have no immediate risk, but both tests have an enormously high false positive rate, which means that the results may send us into a panic, and require not-so-low-risk follow-up tests (eg, amniocentesis), even though everything is almost definitely fine, since we are already in such a low risk group for any of these conditions.

On the false positive rates: 5% of women will get abnormal screen results. Of those women, only 2% of them actually have a problem. So, if 1,000 women take the test, 50 of them will get abnormal results, but only 1 of them actually has a problem, leaving the other 49 in several weeks of panic and follow-up tests for no reason.

S argues that yes, that false positive rate sucks, but honestly, we'll probably be among the 950 women who test normally from the start, at which point we can be happily soothed that nothing is wrong. Which seems very reasonable. Now.

4 comments:

  1. Please visit http://www.jewishgeneticdiseases.org/ for complete genetic screening recommendations for persons of Ashkenazi Jewish descent. While these diseases are more common in the AJ community they occur in all walks of life. The 'Jewish Panel' can consist of 15 diseases!

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  2. Thanks for the pointer! Most of the suggested screenings were the ones that I was trying to get done this weekend (some my doctor does on all Caucasions, and others were the ones that I had to argue with the blood tech about).

    The last few, with the lowest probabilities, I'm just not going to worry about, especially given the very different backgrounds between me and my husband. I am of Ashkenazi Jewish descent, but S. is 100% Japanese. There are very few overlaps in hereditary diseases between these groups, due to the, um, traditionally low overlap between the communities, to put it mildly. (Traditionally, these are two very insular communities!)

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  3. This is an LA Times article that ran on the front page on 12/8

    http://www.latimes.com/news/science/la-me-eggs8dec08,0,6037373.story

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  4. Good luck with the testing. I'm sure everything will be just fine.

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