This post contains important information that many women are not told (much of which even their providers aren't aware!) along with resources to learn more. However, it is not meant to be an exhaustive study of the huge topic of gestational diabetes.
Gestational diabetes is a specific type of diabetes that emerges only during pregnancy. It occurs when the body cannot produce enough insulin to meet the extra needs brought on by pregnancy. This condition leads to elevated blood sugar levels, which can have various implications for both the mother and the baby. If a baby is consistently exposed to unhealthy and very elevated glucose levels from the mother's blood, there is a greater likelihood that they will grow larger than what would otherwise be their natural growth and struggle with blood sugar levels themselves, both immediately after birth and also as they grow. The mother is also now at an increased chance of developing type 1 diabetes outside of pregnancy.
While we believe gestational diabetes is a real condition, there is actually no conclusive evidence behind current diagnostic thresholds and methods, and in light of that, we believe it is wildly overdiagnosed. The way gestational diabetes has been diagnosed has changed in the past and will likely change again in the future. Quite frankly, we still don't know a lot about why some women struggle more than others to manage blood sugar during pregnancy and even the best ways to respond to that. Threshold diagnostics can sometimes even vary from provider to provider, meaning with the same numbers one provider will diagnose you and one will not, leading to potentially VERY different births and outcomes for both mother and baby.
This is all important to know because if a woman IS diagnosed with gestational diabetes (even with all the flaws and lack of evidence therein) it can put her on a trajectory to have the rest of her pregnancy, her birth, and her postpartum time be extraordinarily different than it otherwise would have been without the diagnosis, not just physically but also mentally and emotionally.
When looking for gestational diabetes, the most common screening method is the Glucose Challenge Test (GCT). This involves consuming a glucose drink containing 50 grams of glucose followed by a blood draw after an hour. The intent is to see how quickly the woman's body can manage that much sugar. Most often this drink (usually referred to as Glucola) contains ingredients such as brominated vegetable oil, flavorings, dyes, sodium benzoate, and more that many women find objectionable and would never otherwise consume. The idea of consuming such a large amount of a known unhealthy substance even if in the pursuit of health is worthy of questioning! Because of this objection some providers will give the option of the woman ingesting the 50 grams another way, like jelly beans, a milk shake, or now the Fresh Test, a lemonade drink made specifically to replace the standard glucose drink but with less concerning ingredients.
If the GCT is above a certain range, a Glucose Tolerance Test (GTT) is usually recommended. This test necessitates fasting, a higher glucose drink of 75 or 100 grams, and blood draws at one and two hours.
Some providers will instead use A1C tests over the course of the pregnancy. This evaluates the average blood sugar levels over a period of 2-3 months and is a more accurate overall picture of the woman's blood sugar health.
Many midwives include an option for the woman to monitor her own blood sugar over the course of 3-4 days using a personal glucometer and her normal diet to determine if her body is managing blood sugar well. The usual protocol is to check blood sugar levels upon waking, and two hours after each meal (so four times a day). This method offers a better insight into how her body is responding to her normal diet and also allows her to see in real time how her body responds to different foods or drinks. However, there is room for error with different glucometers that could be an issue with accuracy.
And, of course, women have the option to not screen at all and trust that if everything in the pregnancy points toward normal physiology and health, then there's no reason to. We should always remember that every screening and test now considered standard are actually modern innovations that were never needed for the overwhelming majority of women throughout history.
Until very recently, women only tested at all if they showed symptoms (an unusual and rapid weight gain in the second or third trimester, unquenchable thirst, more frequent urination) or had significant risk factors (very high BMI, type 1 diabetes, some thyroid issues, and more). Some rare providers still practice this way. However, the vast majority of providers now universally screen for gestational diabetes some time between weeks 24 and 28 no matter the mother's personal risk, lifestyle, diet, or whether she is showing any signs of it. It is critical to note here that despite the now near universal screening for gestational diabetes, there is no good evidence that routine screening and the resulting skyrocketing of diagnoses has improved overall outcomes for mothers or babies.
What's also critical to know about gestational diabetes that is often NOT told to women is that even if glucose "challenges" or blood sugar monitoring shows that her body is struggling to keep up with higher insulin demands, if she is able to keep her blood sugar generally balanced through diet, lifestyle, and even medication, she and her baby are at NO GREATER RISK than any other mother and baby. The ENTIRE picture is important. What matters is how much a baby is being consistently exposed to very high glucose levels over the entire course of the pregnancy, though as we alluded to above, what is the cut-off for "high" is actually debated. A woman can have a fasting reading a few numbers “high” and every other reading far below threshold and be diagnosed while another woman can have every reading just at the threshold and not be labeled. In this case the second woman’s baby is actually the one being exposed to more consistent higher glucose!
This means that even if she tests positive and is diagnosed, if she can keep her blood sugar numbers overall in what we understand as a normal range, her risk doesn't change and nothing should change about her birth.
The interventions because of a GD diagnosis have the potential to put a woman and baby at far more risk than if she had been left alone. In mainstream medicine, women who are diagnosed with gestational diabetes are almost always told they should have an induction or cesarean, sometimes as early as 37 weeks. This occurs even if the mother has been managing her blood sugar well and therefore has no increase in risk. This means that the interventions due to the diagnosis are actually more dangerous than the risk of the actual diagnosis.
Broadly speaking, out of hospital midwifery care will be more open to alternative methods of testing as well as respecting a woman's right to decline screening completely. They also tend to be more proactive and supportive with addressing diet and lifestyle not only to avoid issues in the first place but to manage a diagnosis should it occur. However, much depends on the specific midwife.
If a woman does monitor her own blood sugar at home either as a way of screening or as a result of a diagnosis, it's also important to note the limitations there as well. In order to be approved for sale in the United States a monitor can have an error margin of +/- 15%. That’s quite a big deal if a single digit can lead to diagnosis or change the course of the woman's care. Two different glucose monitors can even give different numbers from the very same blood draw.
In short, modern diagnostics, understanding, treatment, and protocols for gestational diabetes have serious issues, flaws, and repercussions and are very worthy of critique. While wildly out of control diabetes does pose a greater chance of complications to the mother and baby, there is much more nuance to the discussion than is almost ever given to women during routine prenatal appointments or when asking questions about testing or diagnosis. Much of what the mainstream system does is not proven and much of it is simply parroted by providers from their licensure or accrediting bodies. Because of this, and because of the basic human rights of a woman to decide for herself what medical tests and interventions she wants to accept and what her own risks and risk tolerance is, it should instead be up to the mother to ultimately decide if she wants to be screened, how she will be screened, and if she does get a diagnosis, what she wants to do about it.
Included below are some really helpful resoures on understanding gestational diabetes itself as well as the limitations of and faults with our current methods of responding to it.
Articles:
Gestational Diabetes: Beyond the Label by Dr. Rachel Reed
Gestational Diabetes by Dr. Sara Wickham
Induction for Gestational Diabetes: What's the Evidence? by Dr. Sara Wickham
Podcast Episodes:
Gestational Diabetes: The Pregnancy Perspective from the Midwive's Cauldron (can also be found on your podcast app)
Gestational Diabetes: The Baby's Perspective from the Midwive's Cauldron (an also be found on your podcast app)
Gestational Diabetes Screening from The Great Birth Rebellion (can also be found on your podcast app)
Books:
Real Food for Gestational Diabetes by Lily Nichols, RDN