Reviewed & Updated January 2019
Please note that this handout is for informational purposes only,
and is not medical advice as I am not a medical professional.
Please use your own discretion before using any of this information
& do further research of your own; consider this a starting point only.
Please consult with trusted health care professionals if you have any questions or concerns.
This handout can be used as a discussion-starter with your primary (medical) caregiver.
Gestational Diabetes testing is a common, even routine, intervention in most pregnancies today. The infamous “orange pop test” is almost seen as a rite of passage, and is certainly understood by many to be a necessary part of ensuring a healthy pregnancy.
The first thing that is crucial to understand when discussing diabetes in pregnancy is the definition of disease. Disease is “a condition of the living animal or ... one of its parts that impairs normal functioning and is typically manifested by distinguishing signs and symptoms” (emphasis mine).
The second thing that is crucial to understand, is that diabetes mellitus type 1 is different from type 2, is different from gestational diabetes. Type 1 diabetes is an autoimmune disease in which the immune system attacks the pancreas, making it incapable of producing insulin. Type 2 diabetes is a disease in which the pancreas eventually stops producing insulin because of prolonged overuse. In other words, type 2 diabetes develops when the body has demanded excess amounts of insulin for a long period of time (obesity & a poor diet are common triggers) and the pancreas eventually wears out. Both type 1 & type 2 diabetes are true diseases as they have distinguishing signs and symptoms which are associated with their diagnosis (increased thirst and urination; extreme hunger; weight loss; fatigue; blurred vision; slow healing wounds) and normal function of the body is impaired. The Society of Obstetricians & Gynecologists of Canada refers to type 1 and type 2 diabetes which are present prior to pregnancy as "pre-gestational diabetes".
Gestational diabetes is defined as glucose intolerance with onset or first recognition during pregnancy with probable resolution after the end of the pregnancy. According to the NIH Clearing House on Diabetes “Gestational diabetes happens when your body can't make enough insulin during pregnancy. …During pregnancy, your body makes more hormones and goes through other changes, such as weight gain. These changes cause your body's cells to use insulin less effectively, a condition called insulin resistance. Insulin resistance increases your body's need for insulin. If your pancreas can't make enough insulin, you will have gestational diabetes. All pregnant women have some insulin resistance during late pregnancy. However, some women have insulin resistance even before they get pregnant, usually because they are overweight. These women start pregnancy with an increased need for insulin and are more likely to have gestational diabetes.”
According to Henci Goer “When you are pregnant, certain hormones make your insulin less effective at transporting glucose, the body’s fuel, out of your bloodstream into your cells. This increases the amount of circulating glucose, making it available to your baby for growth and development. This “insulin resistance” increases as pregnancy advances. As a result, your blood glucose levels after eating rise linearly throughout pregnancy. By the third trimester, you will tend to have higher blood glucose levels after eating than nonpregnant women (hyperglycemia), despite secreting normal and above normal amounts of insulin. During overnight sleep, the excess insulin has a chance to mop up, which causes morning glucose levels to be lower on average than in nonpregnant women (hypoglycemia).”
What all 3 'varieties' of diabetes have in common is high blood sugar levels. What is very different however, is that in type 1 and type 2 diabetes, your blood sugar levels are high during ordinary everyday life circumstances because of a malfunction in your body, and there are specific signs and symptoms which show that your body is struggling. Gestational diabetes is diagnosed when your blood sugar levels are 'too high' after engaging in a test which is for many women artificial in nature as it does not mimic their everyday life or typical eating habits. The testing guidelines and cut-offs vary widely between countries, regions, and even within the same hospital can differ between practitioners. It is important to understand these inconsistencies exist because they mean we have to read any relevant research with the understanding that when we compare studies we may not be comparing apples to apples.
The first level of screening for gestational diabetes tends to be the urine dipstick. (You know – that little stick you pee on at every visit to the doctor or midwife). These test strips have an 11:1 false positive rate when it comes to detecting the presence of sugar in urine. In other words, they’re wrong 11 times more often than they’re right! According to Janelle Komorowski, CNM “Dipsticks may be used for women with suspected gestational diabetes, but as the diagnostic test for gestational diabetes is the glucose test, dipstick usefulness is doubtful. Sugar is found in the urine at some point in pregnancy in about 50% of women, but is not a good predictor of gestational diabetes. Sugar in the urine may be a result of normal physiological changes of pregnancy. Four studies assessed the value of sugar in the urine as a screening for gestational diabetes, and all four concluded there was no evidence for routine urine dipstick testing.” If however you have opted to use urine dipstick testing and find that you have both sugar in your urine AND ketones in your urine at the same time, that may indicate that something is amiss you want to investigate further (Maryn Green - Indie Birth).
The diagnosis of gestational diabetes is made when you “fail” the Glucose Challenge Test/Fasting Glucose Tolerance Test. There is still MUCH debate amongst caregivers around the world as to how much glucose should be given, what acceptable cut off limits are for diagnosis, and whether a one stage or two stage diagnostic procedure is better. Essentially though, after consuming a large set quantity of refined sugar, a blood sample is drawn to see how high your blood sugar levels are. If they are deemed to be too high (ie you didn’t produce enough insulin to compensate for the influx of sugar) then you are given a diagnosis of gestational diabetes. To be more specific, in some places the initial glucose challenge test is a screening tool to determine who may be ‘at risk’ for gestational diabetes, and anyone who ‘fails’ the initial GCT is then sent for a 3-8 hour fasting glucose tolerance test (gtt). If you fail this second test then you are given a diagnosis of gestational diabetes. Some practitioners offer women the option of consuming a set number of jelly beans, a high carbohydrate meal, or other alternatives to the standard glucose drink which is known to cause nausea and vomiting in many pregnant persons. Dr.Aviva Romm has more to say about the problems with 'glucola' drink here.
Diabetic women, particularly those with uncontrolled high blood sugar levels, do indeed have an increased risk of growing a larger than average baby; having a baby with respiratory distress &/or low blood sugar levels at birth; having their baby develop jaundice; and even a higher risk of the baby dying before or soon after birth among other risks. It is important that the pregnancies of women with pre-gestational/type 1 or 2 diabetes be monitored by a qualified caregiver, and that their blood sugar levels are carefully controlled for the wellbeing of both birthing person and baby.
Those with a diagnosis of gestational diabetes are more likely to develop high blood pressure and pre-eclampsia during their pregnancy and each of these complications have substantial risks of their own, however the research has not yet adequately explored whether GD causes the other two or if confounding factors are at play.
It should be noted that 20% of US women between the ages of 20 & 44 are pre-diabetic; 5-10% of women who are diagnosed with gestational diabetes will be diagnosed with diabetes (usually type 2), within 6-12 weeks of giving birth; 35-60% of women diagnosed with gestational diabetes will be diagnosed with diabetes (usually type 2) within the following 10-20 years. These widely varying numbers may well be because the diagnostic cut off criteria for the diagnosis of GDM vary so widely.
The other risk associated with diabetes in pregnancy is that of low breastmilk supply due to insulin dysregulation as breastmilk production is also a complex hormonal process.
A fair bit of research has taken over the last few years, and in early 2013 there was an NIH Consensus Development Conference on Diagnosing Gestational Diabetes held in the USA. Dr. Rebecca Dekker provides a summary of the conference presentations at the following two links, and while it is a lot of science to wade through I encourage you to take time to read her articles as they will provide you with an overview of the most current science.
2013 NIH Conference on GD Day 1
2013 NIH Conference on GD Day 2
The current research does show that lifestyle change based treatment of GD results in some better outcomes than not treating at all, however there are many questions still to be answered and it’s not a clear cut issue. Depending on which outcome you are looking at, between 29 & 60 women diagnosed with GD would have to be treated in order for just 1 of them to see treatment benefits. That is a large number of women who essentially DON’T see any benefit from treatment. “Treating” gestational diabetes includes such measures as making nutritional changes or seeing a diabetic counselor as well as measures like oral medication or insulin injections and clearly those are four very different forms of treatment each with their own risks and benefits. The research also shows that the clearest benefits are for women and babies whose GTT results are in the uppermost limits and that the benefits for all other women diagnosed with GD are much less clear.
So what about your average pregnant woman who is being told she needs to be tested for gestational diabetes? How should blood sugar health be approached in pregnancy for those who are not already diagnosed with pre-gestational/type 1 or 2 diabetes?
I believe that every pregnant person should be paying attention to their diet, and to their levels of physical activity, and if they exhibit troubling signs or symptoms, have personal or significant family history history risk factors, or their intuition and best judgement say they need to pay closer attention to their blood sugar health, they can consider exploring options such as:
random &/or fasting blood glucose testing at home;
regular blood glucose monitoring at home;
Real Food For GD diet;
a general low glycemic index diet;
Brewer pregnancy diet;
working one on one with a qualified nutritionist familiar with best practices;
increasing type &.or level of physical activity;
A1C blood test to get a picture of blood sugar control over the prior 2-3 months;
And of course the standards of care (gct/gtt test, insulin etc) are an option too.
Knowing all the above, what's the potential harm in routine testing & diagnosis?
Ina May Gaskin sums up the issue of Gestational Diabetes like this:
“Gestational Diabetes is not really a disease. Rather, it is a higher level of blood sugar than average during pregnancy, as determined by a glucose tolerance test (GTT). GD differs from diabetes mellitus in that GD goes away after the baby is born. Diabetes mellitus does not. Many doctors recommend this test for all pregnant women, to be performed between twenty-four & twenty-eight weeks of gestation. The test, unfortunately, is not very reliable. Between fifty and seventy percent of women, if retested, will have a different result than they got from the first test. The best evidence we have says there is no treatment for GD, either with diet or with insulin, that improves the outcomes for mothers or their babies. In short, the anxiety that is often produced by this test simply isn’t worth the information gained from it.”
Being diagnosed with gestational diabetes is associated with more frequent ultrasounds and non-stress tests; increased risk of maternal depression; increased risk of induction; increased risk of cesarean section – all of which can bring a level of anxiety with them which may not be acceptable for some pregnant persons especially given that they do not necessarily lead to improved outcomes.
Having a gestational diabetes diagnosis can have a significant impact on birth outcomes for the birthing person, with changes of care provider and chosen birth location frequently coming into play. For some these changes are not just understood but are welcomed while for others they may represent a catastrophic change to their birth intentions.
As with all things pregnancy & birth related, I believe that the right decision for a birthing person is the decision they’re most comfortable with after having considered the relevant information and their individual circumstances. After all – they are the one who has to live with the outcomes of whatever choices they make.
I urge all pregnant persons to listen to their bodies, and respond in ways that promote the health and well-being of themselves and their growing babe. Tune in. Your body knows <3
Recommended Further Reading:
The Truth About GD No Dr Would Tell You - Indie Birth
Glucose Testing in Pregnancy - Aviva Romm
Gestational Diabetes Beyond the Label - Midwife Thinking
Does GD always mean a big baby & induction - Evidence Based Birth
Michel Odent on GD
GD: The Emporer Has No Clothes - Gentle Birth Archives
Gestational Diabetes: A Review For Midwives - AOM
SOGC GD Guidelines
ACOG GD Patient FAQ's
Real Food For GD - Lily Nicolls
The Bump To Baby Low GI Eating Plan - Jenni Brand-Miller et al
The Brewer Diet For GD - Thomas Brewer
Birth Sense: The Common Sense Guide to Creating Your Pregnancy & Birth Plan by Janelle Komorowski, CNM
Ina May’s Guide to Childbirth by Ina May Gaskin
The Thinking Woman’s Guide to Birth by Henci Goer
Gentle Birth, Gentle Mothering by Sarah J Buckley
Real Food For Gestational Diabetes by Lily Nichols