Then join me in trying to understand the science behind the gestational diabetes (GD) phenomenon.
When I was sitting at home, drinking my glucola for the first test, I thought, “I’m sure I will see in my lifetime that this test is completely inaccurate and the powers that be discard it for something else.” Gee, after what I’ve been reading I’m realizing it may be my gift of discernment kicking in.
I’ve tried to do some reading for BASIC INFORMATION regarding this three hour test I have to take. Talk about confusing and conflicting! If you’ve been reading my blog through my whole pregnancy, you already know that we skipped all the genetic testing, despite the fact that I am 39 years old. The results are not reliable enough and there is too much risk for the baby for me to be comfortable with them. (We also would not consider terminating the pregnancy which was the main reason.) After reading about GD I’m thinking the genetic testing sounds a WHOLE LOT more reliable than this GD testing.
I will say right up front that I have a strong sense of this not being right and I have a strong aversion to taking this three hour test. Frankly, I doubted the accuracy of my first test and after reading about what can affect your results, I’m even more doubtful of its accuracy. I also know my own body pretty well and I have some serious concerns about taking the three hour test and how my body will respond. Lastly, after all the nice things I wrote about my doctor a few weeks ago, I was not satisfied with how he responded to my concerns. When I asked him what would happen if I didn’t want to take the three hour, he said that he would put me on insulin. Well, excuse me for being blunt, but it will be a snowy day on the equator before I automatically start taking medication or insulin without trying a lot of other diet adjustments first!
So I came home with some questions and after reading what I can find, I’m even more sure that I’m asking good questions.
First of all, how accurate can a test really be when you are required to ingest large amounts of sugar and then sit around for results? In my mind, it is not rocket science to know that if I don’t eat for 12 hours and then ingest a large amount of concentrated sugar that it is going to do WEIRD things to my body! I mean, really! Imagine telling your OB that you had decided to fast and then sit down and eat a huge bowl of ice cream, a candy bar, and down a couple of Cokes in five minutes. Wouldn’t he tell you that was abusive to both yourself and the baby? If you even told your doctor you were going to fast for 12 hours, he would tell you that was bad for a pregnant woman to do. So even from a common sense standpoint, this test makes little sense to me.
I am also amazed at how inconsistent the information is about HOW to take the test. Until Susan left a comment on my blog, I had heard NOTHING about loading up on carbs the three days before the test. My doctor did not tell me to do this. However, I have found on several reputable websites that I should do this. I’ve also read on several reputable websites that you SHOULDN’T do this. And I’ve read that it makes no difference – your body is going to do what it’s going to do. So what am I supposed to do?
Here is some background on GD from Gestational diabetes: Brief background (bolded sections are mine):
In 1964 O\’Sullivan and Mahan reported that pregnant women with glucose values at the upper end of the spectrum were more likely to develop diabetes later in life; the added stress of pregnancy revealed a woman\’s “predaibetic’ status. Since diabetes was known to pose serious threats to the fetus, researchers extrapolated that subdiabetic levels of glucose intolerance during pregnancy might also do harm.
During the 1960s and 1970s doctors began studying the effects of glucose intolerance in pregnant women; however, the studies were poorly designed [and] thoroughly obscured the true risk of subdiabetic glucose intolerance in pregnancy. Results convinced researchers that they had discovered a serious problem, and in 1979 they convened the first of what became a series of exponentially larger international conferences.
Opening the first conference, one of the organizers suggested that pregnancy be viewed as a “tissue culture experience.” Given the preconceived notions of the researchers, the confused state of the research and a metaphor that reduced women to incubators supplying potentially faulty growth medium, it should come as no surprise that by the end of the second conference, gestational diabetes (GD) was established as a new disease. It was officially defined as: “carbohydate intolerance of variable severity with onset or first recognition during the present pregnancy–irrespective of whether or not insulin is used for treatment or the condition persists after pregnancy. [It includes] the possibility that the glucose intolerance may have antedated the pregnancy.” (Second International Workshop-Conference 1985)
Thus, women with blood glucose values in roughly the upper 3% for pregnant women have come to be defined as diabetics, although the situation is different from either type of true diabetes. The only problem GD shares with Type I and Type II diabetes is that chronic hyperglycemia can overfeed the fetus, resulting in macrosomia . Even here, other factors-race, age, parity and especially maternal weight far outweigh glucose intolerance in determining the baby’s weight.
The conference definition of GD confuses more than it enlightens because it jumbles together various levels of severity. This is similar to claiming that everyone with a cough and fever has pneumonia. The confusion was deliberate. The conferees considered using the term “glucose intolerance of pregnancy” but decided on “diabetes” to make sure insurance companies would pay for high-risk management and women themselves would take the condition seriously.
The 1985 conference recommended-and the 1990 conference reaffirmed-that all pregnant women be screened for GD between 24 and 28 weeks by a 50 g glucose drink and that those with values of 140 mg/dl or above be given a diagnostic 100-g oral glucose tolerance test (OGTT). Women with two values meeting or exceeding O\’Sullivan and Mahan’s values on the follow-up OGTT should be considered to have gestational diabetes. The American Diabetes Association endorsed the conference recommendations. The American College of Obstetricians and Gynecologists recommends the same screening and diagnostic values; however, it recommends selected screening only for women under age 30.
Keep in mind that O\’Sullivan and Mahan chose their cutoffs for convenience in follow-up. No threshold has ever been demonstrated for onset or marked increase in fetal complications below levels diagnostic of diabetes. Instead of raising questions about the validity of GD testing, this lack of correlation with complications has led some researchers to lobby for a lowering of diagnostic thresholds, which would label even more women gestational diabetics.
-Henci Goer, Obstetic Myths Versus research Realities, A Guide to the Medical Literature, Bergin & Garvey 1995
Reprinted from Midwifery Today E-News (Vol 1 Issue 47, Nov 19, 1999)
Here are some other key thoughts I found from this article: Gestational diabetes: myth or metabolism?
Many birth practitioners question the existence of “gestational diabetes” because it is often diagnosed solely on the basis of a response to a test. Why would a nonsymptomatic mother show elevated blood sugar levels? Perhaps her body is reflecting the chemical gymnastics imposed by the test itself–which may involve fasting followed by the consumption of large doses of concentrated glucose. Or perhaps her body is registering a healthy response to the inherent dynamics of pregnancy.
Blood sugar elevations during pregnancy can result from several factors. Any of the root causes of clinical diabetes mentioned earlier may be operative. Another possibility is that the placenta secretes lactogen, estrogen, and progesterone–hormones that counteract the function of insulin–as well as potent enzymes that destroy insulin. (13) Would the placenta, an organ designed to sustain pregnancy and nourish a baby for nine months, consistently make this “mistake”?
It is important to understand that the body handles glucose differently during pregnancy. In Birthrights, Sally Inch explains one reason for the pregnant body’s need for “hyperglycemia” (higher blood sugars): “Instead of being rapidly converted to glycogen and stored in the liver for future use, the glucose remains for longer periods in the [woman’s] bloodstream so that her developing baby has an easily available source of energy that can be used for growth and storage as fat (+ glycogen).” (14)
A major problem with both standardized tests is the long period of fasting that is required. (22) Even a wellnourished pregnant woman depletes the glycogen supplies in her liver after 12 hours of fasting. (An undernourished woman may deplete her glycogen stores soon after each meal is digested.) This depletion causes the nausea that many women experience after eight to 12 hours without food. Ideally, pregnant women should eat something every two to three hours around the clock.
The glucose tolerance test (GTT) is often considered the most definitive procedure for determining whether or not glucose is being properly managed. The GTT requires an eight-to 12-hour fast, after which the first blood sample is taken to determine a fasting glucose level. Then the woman drinks 50 to 100 grams (2 to 4 ounces) of concentrated glucose (glucola), and blood and urine samples are taken at half-hour (sometimes omitted), one-hour, two-hour, and three-hour intervals. Infrequently, a five-hour sample is taken. The normal blood plasma values for the three-hour GTT are as follows: fasting–<105 mg/100 ml; halfhour–<200 mg/100 ml; one hour–<190 mg/100 ml; two hours–<165 mg/100 ml; and three hours–<145 mg/100 ml. Normal values are lower when whole blood is tested.(27)
Because of the widespread use of the GTT, it is important to be aware of its drawbacks. First, the mother is required to fast for eight to 12 hours before being tested. Secondly, several factors can lead to false-positive results: “It is mandatory that the patient be on a preparatory diet containing 250 to 300 g carbohydrate for three days before testing; otherwise a decreased carbohydrate tolerance may be observed, known as starvation diabetes. Physical inactivity also decreases carbohydrate tolerance, and therefore prolonged bedrest may give false-positive results.”(28) Women taking the GTT or the one-hour glucose test are advised to take a long walk–from 1 to 3 miles–between ingesting the glucose and having each blood sample drawn, as this will tend to lower the blood sugar levels. And thirdly, the GTT floods the mother and baby with high levels of concentrated glucose. The effects of glucose flooding, particularly after several hours of fasting, are unknown.
Finally, one of the greatest problems with the GTT is its inaccuracy. Influences such as diet, age, stress, fever, infection, overwork, lack of exercise, illness, and worry can easily cause unreliable results. Even anxiety about the needles or about the consequences of test results can provoke a flood of epinephrine, which in turn releases glucose and blocks insulin release, resulting in unusually high recordings of glucose levels.(29)
How accurate can the GTT be, and how accurate is it? Dr. Edward Pinckney writes in Dissent in Medicine that and excellent test is right at least 97 percent of the time, a good test is right 95 percent of the time, and any test that is less than 80 percent accurate should not be undertaken until its potential benefits are shown to outweigh its known risks.(30) According to Foster in Harrison’s Principles of Internal Medicine, 75 percent of clients shown by the GTT to have “impaired glucose tolerance” (a possible tendency for diabetes) never actually develop diabetes.(31) The implication is that positive GTT results are accurate only 25 percent of the time.
How reliable is prenatal diabetic evaluation? In 1979, the National Diabetes Data Group lowered the commonly accepted standards for normal glucose levels in pregnancy. The upper limit for the fasting glucose test dropped to 105 mg/100 ml from the previously accepted level of 140 mg/100 ml. The upper limit for the two-hour postprandial test dropped to 120 mg/100 ml from 150 mg/100 ml.(32) Consequently, many well-nourished women with normal plasma glucose levels before 1979 would now be considered to have abnormal glucose levels and would be diagnosed as having “gestational diabetes.”
The diagnosis and treatment of “gestational diabetes” elicits four major objections from birthing reform advocates. The pregnant body is not recognized as being different from the nonpregnant body and is therefore not expected to function within different parameters of normal.(33) Isolating and treating a woman’s metabolism of sugar, without taking into account the many other dynamics of her pregnancy, leads to misdiagnosis and complications. Pregnant bodies should not be metabolically forced to act the way non-pregnant bodies do. . The pregnant woman is diagnosed purely on the basis of a test and is not perceived in the context of her multifaceted life. Laboratory results that are used as more than ancillary guides to diagnosis lead to false conclusions. The many factors that can influence a woman’s blood sugar level must be investigated. Is her insulin production being affected by a virus (mumps, hepatitis, infectious mononucleosis, congenital rubella, or Coxsackie) that she may have been exposed to shortly before or after conception? Is her insulin production being inhibited by diuretics, adrenalin (due to anxiety or stress), or a diet high in unsaturated fats and low in magnesium and vitamin B-6? Is she afraid of needles, hospitals, or medical settings in general? Could she be experiencing starvation diabetes from morning sickness, the flu, or the belief that she should restrict her weight gain? Has her insulin been tested to see if it is an unusual type? Is she on bedrest or living a sedentary lifestyle? Is she overworked or worried? Does she have an infection? Is she having conflicts in her personal relationships?
Do babies born to mothers diagnosed as “gestationally diabetic” require continuous monitoring? Some pediatricians say no. They feel that if the mother’s blood sugar levels are not abnormally high, her baby will not have problems with hypoglycemia. Dr. Robert Mendelsohn, author of How to Raise a Healthy Child…In Spite of Your Doctor, took this one step further. He claimed that “gestational diabetes” does not exist and that the baby born to a mother diagnosed as such does not need to be tested.
Is “gestational diabetes” a defect in metabolism or a myth borne out of a misunderstanding of normal pregnancy? The definitive answer is not in yet. Unfortunately, as Elizabeth Noble says, “a great many people share the medical establishment’s mechanistic view that control of nature is good and that progress is only a matter of more–more pills, more techniques, more information.”(34)
It is unrealistic and unreasonable to routinely screen the entire pregnant population for diabetic tendencies. According to Tom Brewer, no study in any of the medical literature indicates adverse effects from “gestational diabetes.” The effects that are usually referred to, he says, are found in poorly nourished women with poorly controlled “real” (clinical) diabetes. It is quite possible that “gestational diabetes” in the well-nourished woman is simply evidence of her body trying to do its job of growing and birthing a healthy baby.
Another website offered this insight:
In the three-hour Glucose Tolerance Test (GTT), it is very important to fast beforehand, however. This test is designed to see how your body responds to a lot of carbohydrates all at once—-whether your insulin response can keep up with the demand, as it were, since insulin resistance increases in pregnancy. In this test, the woman is given a 100g drink of glucola, twice the level of the other test. Four blood draws are usually taken. One draw is in the fasting state, then the next draws are at one hour, two hours, and three hours after drinking the glucola. (Occasionally, a draw will also be done 30 minutes after the drink as well, but that is less common.) Another procedure that sometimes varies is whether they require a urine test at each draw as well.
Things that can interfere with the accuracy of this test include smoking, caffeine, bedrest (meaning no exercise), excessive stress, illness, and many medications (such as prednisone or other glucocorticoids, progesterone supplements, terbutaline, etc.). Also implicated in questions on the test’s accuracy is whether the woman consumed adequate carbohydrates for 3 days prior to the GTT.
Generally speaking, the woman is supposed to “carbo-load” for several days before a GTT. This apparently stimulates her body to produce more insulin and be more prepared for the overload of the 100g test. However, many doctors do not instruct their patients on this at all, and some even forget to tell the patient to fast ahead of time. In addition, even those who tell their patients to carbo-load do not give consistent advice. Some give a specific diet to follow, specifying exactly how many extra carbs to eat and when (usually >150g–10 servings or more–of carbs per day; remember that carbs in this case includes all starches, fruits, sweets, and dairy products). On the other hand, other doctors just tell the woman to eat a few extra servings of carbs 1-2 days before the test. Be sure to press your doctor for more details on this and question your care closely if the doctor seems careless in attitude towards the test protocols. The official recommendation is to carbo-load for at least 3 days before the test, but since many doctors do not follow this, the lack of uniform testing conditions is a major criticism of this test.
There are a number of concerns about the current gd testing protocols. Inconsistencies in testing conditions, reproducibility of the tests, whether one test can adequately sample the changing nature of glucose tolerance during pregnancy, the relationship of the test results to fetal outcome, whether testing accurately reflects ‘real-life’ conditions, the susceptibility of tests results to influence from life factors such as stress and illness, should the diagnostic levels be stricter or looser based on fetal outcome, and the cost-effectiveness of a nearly universal screening program, etc. are all important gd testing issues. There is great debate currently occurring over these concerns.
The inconsistency with which the glucose tests are administered is a very important criticism. Doctors are extremely inconsistent in the way they give these tests or tell you to prepare for it. If a test is not given under uniform conditions, then the results are open for questioning. Unfortunately, this is not well-addressed in the medical community. Most neglect to have the patient carbohydrate-load before the test and do not specify a consistent fasting recommendation (9 hours, 10 hours, 12 hours, etc.). Some use urine testing in conjunction with the tests, some do not. Some measure at the first half-hour as well as the usual 1 hour, 2 hour, and 3 hour intervals after ingesting the glucola, while most do not. Some prohibit any movement at all while others permit light walking or activity. Some providers use BG meters to measure the 50g-1 hour test more conveniently in the office, while others consider this invalid. Some providers tell women to fast before the 1hour test, while others tell them to have at least 2 hours between their last meal and the test, while still others tell women it makes no difference at all. Some providers even neglect to mention that the 3 hour test is a fasting test, causing women to either have inaccurate results or causing them to need to reschedule the test.
The overwhelming sloppiness with which the medical community administers these glucose tests is a very strong criticism and should be carefully addressed; unfortunately it is an issue that receives little attention in the research literature or from providers in general. And as noted above, another study (Solomon 1996) showed that nearly 25% of doctors surveyed incorrectly diagnosed gd from patient test results, so doctor error or protocol differences is an important factor too.
Also open for questioning is the reproducibility of the test—whether the same results will be obtained each time. Some studies (Harlass 1991) show that the GTT is not very reproducible, which is a significant concern since a woman could conceivably be misdiagnosed, either positively or negatively. This area needs more research. Blank et al. (1995) note that, “Another problem with conventional screening and diagnostic methods that use the standard glucose tolerance test is that the results are not very reproducible. Thus, there may be false-positive readings, as well as false-negative ones. A large percentage of positive screening tests will be negative upon retesting.” Since the label of ‘gd’ has been shown to increase rates of c-sections and other interventions independent of any other complicating factors, careful attention should be paid to the issue of misdiagnoses.
Another concern is that drinking 100g of sugar drink is not like real life, and it is more important how your body responds to everyday, real-life conditions. Because sugar (or glucola) is a simple carbohydrate and there is no protein or fat to help slow its absorption, it will produce the most extreme reaction and test your insulin capabilities more. 100g of other carbs, on the other hand, might be absorbed differently, especially if protein or fat is eaten with it.
On the one hand, it is easier to standardize the testing through the use of the glucola and it tests the pregnant woman’s reactions to the most extreme stimulation, just in case she is eating a great deal of candy and sugar. On the other hand, the criticism that this doesn’t often reflect real-life situations (which rarely include consuming 100g of pure sugar without protein or fats of any kind) is also valid. However, it is not as hard as it seems to take in 100g of carbohydrates of various kinds, so perhaps a load of this kind is justified, though it seems to be stacking the deck a bit, since such an occurrence without protein and fats would be unusual. Some providers would prefer that the testing conditions more accurately reflect real-life situations, but the testing for this would be cumbersome and more expensive. The truth is that glucola tests are fairly easy to standardize and more clear-cut to give, and most providers are not willing to indulge in more cumbersome regimens.
No matter what type of test is given, one recurring problem is that many life factors can also influence the results. Blood glucose levels are extremely susceptible to stress, for example. If you are under a great deal of stress the week of the test or if you don’t get a good night’s sleep the night of the test, your results can be elevated. Illness can also substantially increase your bG levels. Of course, the argument can be made that if your levels are elevated, it doesn’t matter if it’s due to stress or lack of sleep or whatever—it’s still more of a risk for baby. This is true. On the other hand, if you have have been ill, had a bad night or stress that is not usual, you might want to ask about postponing the test to another day. Doctors will differ in their response to this, but frankly, most will probably not have you reschedule. This is another point critics use against this kind of testing, though its value is debatable. Other factors that can alter lower glucose tolerance include many medications, caffeine, nicotine, and enforced bed rest. If any of these (or unusual stress or illness) are factors for you, discuss the issue with your provider. Some may be more flexible than others.
Well, so that’s what I’ve been thinking about on this steamy July Sunday. I had originally scheduled my test for tomorrow morning, but then heard about the carbo-loading from Susan and thought that I should probably look into that and so I rescheduled my test for later this week. However, after reading all that I have, David and I have some real questions about this whole thing. My doctor is on vacation until Thursday so I am going to think about all of this and decide what to do. I am thinking I may just cancel my test until I can talk with him. If anyone has any experience with this (especially refusing the test), I’d love to hear about it!