How do practitioners test for gestational diabetes?

Gestational diabetes is typically tested using the oral glucose tolerance test (OGTT). When you arrive at your practitioner’s office, you will be given a drink that contains 50 grams of glucose and told to consume it in five minutes. This is usually a standard beverage provided by a drug manufacturer, but some practitioners will allow you to drink a regular soda or even eat jelly beans.

It would have been hard to resist the test if I could have eaten these yummy jelly beans :)

Ingredients: purified water, 50g Dextrose (D-glucose derived from corn), Citric Acid, Natural and Artificial Flavors, Sodium Benzoate, 0.1%, FD&C Yellow #6. It also labeled as “Gluten Free & Dairy Free”. What else is in this drink? I had a hard time finding an ingredient list, but a kind reader who had a bottle of the orange flavor (because she also refused the test and never drank it) shared the ingredients of this artificially sweetened, artificially flavored drink with me.

An hour after consuming 50 grams of glucose, your blood will be drawn. Typically, a blood glucose level of 140 mg/dl or above means further testing to more accurately diagnose gestational diabetes in the form of a three-hour OGTT. You get to consume the fake, sugary beverage again and this time you get to sit around and have your blood drawn once an hour for three hours and you aren’t allowed to eat or drink anything for the duration of the exam. I wouldn’t want to do this on a regular day, much less during pregnancy!

I had a couple of concerns as I learned more about the OGTT. 

First, how would my body react to ingesting such a high dose of sugar in one sitting? Would I get dizzy, throw up or maybe even pass out? It has been a long time since I have had that much sugar and on the few occasions where I have had too much sugar in the past year, it affected how I felt for the whole day.  

Second, would the results be accurate? Most days, my sugar consumption is limited to fresh fruit, dried fruit and maybe some natural sweeteners such as honey or molasses. I was concerned that this could affect my results and I would end up with a false positive.