Glucose Tolerance Test and Gestational Diabetes

You'd think that after all the tests you were offered back in the first trimester, we'd be just about done with the genetic screening by now, wouldn't you? Turns out, your doctor or midwife is just getting started.


Gestational diabetes isn't a fun thing to talk about, neither is getting your blood drawn, drinking an obscene amount of sugary "liquid", or any of the other things required for testing. However, if you fit into one or more of the risk factors, you might want to think about buckling down and getting the test. 

Keep reading to find out about an alternative if you're interested!

Sometimes referred to as the "glucose challenge," or "GTT," or- more colloquially- "the diabetes test". This test is a way of determining if mama has developed gestational diabetes. Sometime between weeks 24 and 28 of your pregnancy, your healthcare provider will ask you to drink a high-sugar, pretty nasty-tasting "beverage" called Glucola. One hour later, your blood will be drawn to measure your blood sugar response. Mamas who test positive after the GTT will be asked to take a three-hour version which is considered diagnostic. 

It's not necessary to fast in advance of the GTT. In fact, fasting can potentially result in a false positive, which is why some midwives recommend that you up your carb intake for two or three days leading up to the test, in order for your body to get used to processing the excess sugar.


Is this test right 

for you?

While you can decline the GTT, just as you can decline any prenatal test during your pregnancy, gestational diabetes is a condition you don't want to go unnoticed. Women with gestational diabetes are more likely to have large babies, which can be difficult to deliver vaginally; they also experience higher rates of Cesarean & are more likely to develop type 2 diabetes later in life. 

Babies born to women with gestational diabetes, meanwhile, may have dangerously low blood sugar or problems regulating their blood sugar after birth; they're also at higher risk of obesity. 

Screening for gestational diabetes may be especially important for women who have the following risk factors:

  •  You are twenty-five years of age or older
  • You were overweight before becoming pregnant
  • You have a family history of diabetes
  • You are of Hispanic, African American, American Indian, Asian American, or Pacific Islander heritage.
  • You have a previous history of abnormal glucose levels or had gestational diabetes during a previous pregnancy

BUT WAIT! There's an alternative to Glucola???

I have major issues with Glucola. For one thing, it's loaded with chemical food dyes and additives, modified corn starch, brominated vegetable oil, and dextrose- exactly the type of stuff we typically try to avoid during pregnancy, if not all the time. Luckily, there are alternatives! Midwives in particular tend to be more willing to screen for gestational diabetes using food-based tests- orange juice, dates, and all natural jellybeans are all common stand-ins.

The makers of Glucola produce a dye-free version, which you can request. You can also inquire about "spot checking," where your healthcare provider checks your blood sugar from a drop of blood drawn via a finger prick. 

These kinds of alternative tests have been used for years, though it's worth mentioning that from a large-scale, randomized trial standpoint, evidence that they are as effective as Glucola is still inconclusive.



You may want to consider what would happen in the event you tested positive. Treatment for gestational diabetes always includes modifying the diet and getting exercise. If you already eat a low-sugar, real food diet and exercise regularly, however, you likely wouldn't have to change much about your lifestyle and may be an excellent candidate for alternative testing. If on the other hand, you eat lots of processed foods, lead a sedentary lifestyle, and have a number of risk factors, you'll want to start focusing on improving your health now; don't wait for a GTT to give you the bad news.