QuestionI failed my 1-hour glucose screening (result was 150). I'm scheduled to take the 3-hour GTT. I was instructed to, on each of two days prior to my test, eat 6 slices of bread or 3 candy bars. Then I'm to fast starting at midnight the night before the test (my test is at 8 am).
I'm confused. Why load up on carbs, including simple carbs like in the candy bars, in the days preceding the test. Won't that just increase my risk of a false positive result?
Also, what are my chances of failing the 3-hour test given my 1-hour results, the fact that I have no family history of diabetes, I did not have GD with my first pregnancy and I am relatively small-framed (was 5'4" and 112 lbs prior to this pregnancy).
Thank you!
AnswerThe purpose of the 3 hour glucose tolerance test is to see how quickly your body gets rid of a carbohydrate load. That is why we load your body with carbohydrates prior to the test. The 1 hour GGT was merely a screening test to see what your glucose was at 28 weeks while eating regularly. You should not fast prior to the 1 hour test, but should fast prior to the 3 hour test. At each hour of the 3 hour test, your glucose will be tested and a curve will be generated. If this is within normal limits, you are fine. If there are two abnormal values in the test, it indicates gestational diabetes and you will be placed on a special diet. I doubt that you have GD because your 1 hour test was only 150. HOwever, our cut off for a normal 1 hour test is 140 and anything higher than that behooves us to send the patient for a 3 hour test (which is the definitive test). It does not mean that you have diabetes or will get it in the future. Don't worry.
