The OGTT-A day I have been dreading for awhile (afraid of possibly going into insulin shock), ingest 50-100g of sugar and have your blood drawn and then see how fast your body can clear out the glucose. If you fail, you are insulin resistant and thus have "gestational diabetes". Failure results in one of two things, 1 - you have one more shot, you get to do this test for 4 hours & consume lots more sugar or 2- you have been diagnosed with "gestational diabetes" and now have to monitor your glucose for and extended period of time while consulting with an "expert" on nutrition.
If you consume a large bolus (75-100g) of glucose and fail to clear it in a timely manner, you are insulin resistant and thus have “gestational diabetes” (GD). I’ve written on this topic before and the whole thing makes me want to lobotomize myself with a blunt instrument. It’s a tough and incendiary topic. On the one hand our medical professionals deal with a huge population of women who eat very poorly, never exercise and somehow still manage to get pregnant. Miracle that this situation is, biology makes things worse. During pregnancy the mom becomes even more insulin resistant due to an evolutionary adaption in mammalian-mom’s in which they become slightly insulin resistant to allow a positive flow of nutrients to the developing fetus via the placenta. If the mom was more insulin sensitive than the fetus we could end up in a nutrient scarcity situation due to nutrition flowing to the more ubiquitous tissues of the mom. Biology fixes this problem by making mom a little insulin resistant, effectively “pushing” nutrients to the fetus. Score one for biology! Problems arise however when our modern diet and lifestyle make this otherwise favorable adaptation dangerous. Too many carbs (particularly chronic fructose intake), autoimmune complications with lectins, loss of insulin sensitivity due to sleep deprivation and stress can drive expecting moms into gestational diabetes. From the paper linked above we have an interesting observation that severity of GD is likely determined in part by estrogen and progesterone levels. One of the key features of hyperinsulinism is a decrease in sex hormone binding protein (SHBP) which then makes estrogen more available to the tissues. Interestingly, this problem with estrogen is actually at the heart of most female infertility, but that is a topic for another day (or a book…)
Thinking and reading has led me to believe that giving pregnant women an Hb1Ac blood test would be a much better indicator of diabetic risk than OGTT and would limit the false results and possible insulin shock!