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 a health care professional 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.
Gestational diabetes is defined as “glucose intolerance with onset or first recognition during 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. Gestional diabetes is diagnosed when your blood sugar levels are 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 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). 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.”
The diagnosis of gestational diabetes is made when you “fail” the Glucose Challenge Test/Fasting Glucose Tolerance Test. There is still some 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 countries 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 or a high carbohydrate meal instead of the standard glucose drink.
Diabetic women, especially 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 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 mother and baby.
Women 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. 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.
All that being said……
According to Matthew Sermer in the Feb 2003 issue of CAMJ, “ Some physicians in Canada do not believe that this condition (gestational diabetes) exists, and others feel that its importance is so low that screening is not justified. Many researchers…are trying to shed light on this subject, but the controversy will only end once a robust, randomized, double-blind trial is conducted to demonstrate whether identification and management of gestational diabetes is associated with significant improvement in neonatal or maternal outcome. Unfortunately, no such study is yet under way. While waiting for the results of such a trial, it would be reasonable to follow the SOGC guidelines published in November 2002.”
These guidelines can be found at the following link and are the current guidelines in Canada as of January 2014: http://sogc.org/guidelines/screening-for-gestational-diabetes/
A fair bit of research has taken place since 2003, 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.
The current research does show that 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 black and white 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 women who are not already diagnosed with type 1 or 2 diabetes? I believe that every pregnant woman should be paying attention to her diet, and to her levels of physical activity, and if she exhibits troubling signs or symptoms or has personal/family history and risk factors which indicate that her body could be struggling to maintain healthy blood sugar levels, she can consider exploring options such as: a low glycemic index diet; working with a qualified nutritionist; increasing her levels of physical activity; keeping a food diary; blood glucose monitoring with a glucometer; an A1C blood test to get a picture of her 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. Keep in mind that the SOGC says in their practice bulletin “that until evidence is available from large RCTs that show a clear benefit from screening for glucose intolerance in pregnancy, the option of not screening for GDM is considered acceptable. Conversely, there are no compelling data to stop screening when it is practiced.”
Knowing all of this, what’s the potential harm in testing for gestational diabetes?
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 women.
As with all things pregnancy & birth related, I believe that the right decision for a woman is the decision she’s most comfortable with after having considered the relevant information and her individual circumstances. After all – she’s the one who has to live with the outcomes of whatever choices she makes.
I urge all pregnant women to listen to their bodies, and respond in ways that promote the health and well-being of themselves and their growing babe.
References & Recommended Further Reading:
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