Gestational Diabetes Screening - A Summary
by Kmom
Copyright © 1996-2002 Kmom@Vireday.Com. All rights reserved.
Last updated: September, 2002
DISCLAIMER: The information on this website is not intended and should not be construed as medical advice. Consult your health provider.
SPECIAL NOTE: It is not in the scope of this FAQ to truly cover all prenatal testing thoroughly, only to address it in general and as it concerns big moms. Kmom urges all pregnant women to thoroughly research any test before deciding whether to use it or not. Do NOT accept blindly what your doctor tells you. Ask questions and consider all sides of the issue. Testing decisions vary greatly depending on family history, medical condition, parental beliefs, etc. For more information on prenatal testing, see the FAQs available from misc.kids.info and the many other prenatal testing FAQs on the Internet.
CONTENTS
"The technology of prenatal diagnosis is usually presented to us as a solution, but it brings with it problems of its own...the technology of prenatal diagnosis has changed and continues to change women's experience of pregnancy."
---Barbara Katz Rothman, The Tentative Pregnancy
Note: The introduction is the same in each section of the Prenatal Testing FAQs. Kmom feels it was important enough to repeat it in each section of the Prenatal Testing FAQs. However, if you've already read it, you may want to skip ahead.
All pregnant women in our technology-happy modern society face confusing choices about prenatal testing, its advantages and disadvantages, and its appropriateness for them. Large pregnant women face even more confusion, since prenatal testing can be slightly harder in this population, and the results can be more confusing. However, since they may be at a somewhat increased risk for problems like neural tube defects, they also face greater pressure than others to have these prenatal tests, even though the tests are often difficult to interpret.
This section is an attempt to present an overview of the most basic prenatal tests most pregnant women in the US are pressured to have, including Ultrasounds, the AFP/Triple Screen Test, Gestational Diabetes tests, and under certain conditions, Amniocentesis. It is further designed to address the special concerns that large women might have in taking these tests---their fears, any special equipment that might be helpful, the controversies over interpretation of results, whether large women have a higher rate of so-called 'false-positives' on certain tests and why, etc.
It's important to remember that discussing prenatal tests can be simple or incredibly complicated, depending on the degree of detail that is needed and the point under discussion. This FAQ is NOT intended to be a full explanation of all the intricacies of taking and interpreting various prenatal tests, but rather a discussion of them as they pertain to large women instead. A brief description of the test, its purpose, and the procedures are given for each, but the majority of the information is about the specifics of large women and the test. If you need more detail about statistics, interpretation of results, rates of 'false-positives', etc., then be sure to research the many websites devoted to prenatal testing online.
It is also important to realize that most women take these tests without fully considering all of the implications of the test. Most women think of these as a simple blood test, a cursory part of prenatal care. They don't consider that intimately wrapped up in the question of prenatal testing is the moral dilemma of abortion and the thorny issue of eugenics. Barbara Katz Rothman points out:
The history of prenatal diagnosis has roots in the eugenics movement...part of its history has been an attempt to control the gates of life: to decide who is, and who is not, fit to make a contribution to the gene pool.
Katz Rothman is by no means arguing against the use of prenatal testing; she actually presents a number of compelling reasons to consider it. Her writing is a fair and balanced look at the intricacies and difficulties of this issue. But she has found through extensive interviewing of parents involved in such testing that most of them were simply unprepared to confront the scope of the types of decisions presented by prenatal testing, and that choosing such testing often changed the way a woman experienced pregnancy in subtle ways.
Parents who are considering using prenatal testing need to be sure they really understand the following issues BEFORE the test takes place:
More on these kinds of questions is available on other websites about prenatal testing, but it vitally important that parents think about these issues BEFORE they decide whether or not to test.
Readers may feel that there is a strong anti-testing bias in this FAQ. Kmom's own experiences with prenatal testing (detailed below) have largely been negative, and she is certainly strongly concerned that so many women enter into these tests without really considering what they are doing beforehand. Part of the purpose of this FAQ is to help women understand the scenarios they might face should their screening test come back positive for possible problems. And because the overall bias of our technological culture is towards doing more and more testing, she feels an extra responsibility to challenge the automatic assumption that more testing is better.
However, by no means is she condemning testing completely, nor does she criticize those who do choose to test. Prenatal testing has certain advantages and in some situations can be a great help. And under certain circumstances, Kmom would choose to use some of it too. She is simply pointing out that the issue is far more complex than most clinicians would have patients consider, and that parents need to ask themselves the hard questions before they begin the process.
Finally, it's also important to note that none of these tests are mandatory. Although many women are simply told that they will be taking these tests, it is ALWAYS your right to decline any or all of these tests. Just because you are 35 or over, for example, does not mean that you HAVE to have an amnio, and just because you are a large woman does NOT mean that you have to have the AFP test or gestational diabetes test. Conversely, it is also your right to request certain tests if they are important to you.
You have the right to accept or decline any test or treatment during pregnancy. It is YOUR body, and YOU have the ultimate choice. Research the issues carefully so that you make an informed choice, and then either request or decline the test, based on your individual needs and values. Don't let any provider try to bully you into (or out of) tests---listen to their counsel, do your own research, and then MAKE YOUR OWN CHOICES.
This section is a very short summary of the tests for gestational diabetes, since this is part of the usual battery of prenatal tests given to most pregnant women (and especially large moms). However, GD and its testing is a very complex subject and cannot be covered thoroughly here.
Readers are strongly urged to consult the websection on this site devoted to Gestational Diabetes; there is an entire FAQ there devoted simply to issues about GD Testing, with much more detail than can be found here. Other websites also have quite a bit of information about GD and its testing; a list of some of these websites can be found in the Introduction to GD and What Is GD FAQs on this website. In addition, more FAQs covering many aspects of gestation diabetes can be found on this site. For more information on these other FAQs, check out the GD: Index page.
It is a normal function of pregnancy for the digestion to slow down and for the body to become more resistant to insulin. This is beneficial to baby, because it helps the body extract more nutrition and more energy (glucose) from the mother's food. The placenta is supposed to create extra amounts of certain hormones in order to help this process and nourish the baby more efficiently. Increased insulin resistance in pregnancy is normal.
The woman's pancreas is supposed to respond by creating even more insulin in order to keep the mother's blood sugar in the normal range. And in fact, most pregnant women are able to create enough insulin to compensate for the temporary insulin resistance/carbohydrate intolerance brought on by pregnancy. However, about 4-6% of the overall U.S. population (more in some areas and groups) cannot compensate for the hormonal effects of pregnancy. In these women, blood sugar may rise above what some doctors have decreed as 'normal.'
Basically, gestational diabetes (as currently defined by the traditional medical establishment) is thought to occur when placental hormones in pregnancy overwhelm the capacity of the mother's pancreas to produce enough insulin to keep her blood sugar in the 'normal' range. It can occur because the mother's pancreas does not produce enough insulin (a "beta cell defect") or because the mother becomes excessively resistant to her insulin, despite producing large amounts of it.
But at what point do higher blood sugar levels become a problem? This is one of the key questions of GD, and there is no clear answer. It is clear that very high blood sugar levels can be quite harmful to the baby, increasing the risk for an abnormally large baby and even stillbirth. However, there is a great deal of debate about whether mild degrees of this are truly a concern, and at what point concern is justified.
At this point, there are no truly definitive cutoffs for when blood sugars become really harmful. Current diagnostic standards are based on preliminary research and to a certain extent, guesswork. Standards were developed many years ago, and were primarily based on future prediction of maternal diabetes, not on fetal outcomes. Therefore, controversy as to the "best" cutoffs for diagnosing GD and preventing fetal harm rages on in the research world. Studies on this controversial issue are ongoing.
Some researchers believe that ANY degree of carbohydrate intolerance in pregnancy is harmful. They advocate drastically lowering the current diagnostic cutoffs for GD, and using insulin more often when GD is diagnosed. They often also believe that significant interventions (such as close fetal monitoring, early induction of labor, extensive testing of the newborn) is necessary with GD, even borderline cases.
Other researchers are comfortable that the current cutoffs used for diagnosing GD are appropriate and beneficial. They believe that GD is real, that treatment is beneficial and justified, and that further research will uphold the current standards and protocols.
Still other researchers contend that mild carbohydrate intolerance in pregnancy is the pregnant system's way of adapting to the higher energy needs of pregnancy, and in mild degrees this is totally normal and does not warrant any concern. Some researchers have even called GD "a diagnosis in search of a disease."
Many critics also contend that treatment for 'GD' tends to be too strict, involves huge amounts of dubious interventions (such as early induction of labor), and does not improve outcomes. In some cases, they believe treatment for 'GD' actually worsens outcome (i.e., a very high rate of c-sections). Thus the potential "benefits" of GD treatment may be outweighed by other risks that accompany treatment.
It is true that research on GD tends to be mixed, and that not all countries around the world believe in doing routine 'GD' testing. However, most providers here in the USA have bought into 'gestational diabetes' as a disease and so test for it routinely in pregnancy. Therefore, testing at about 26-28 weeks is considered "standard of care" here in the U.S. in most practices. However, there are practices that either do not test for GD, test only minimally for GD, or are willing to consider alternative forms of testing. If you are opposed to taking the GD tests, you can find providers who will be more flexible about it.
A debate over the relative risks and benefits of the gestational diabetes diagnosis and treatment can be found on this website under the section, GD: An Introduction. In contrast, the summary found here is only a very basic introduction to GD testing issues. It is presented here as part of the Prenatal Testing FAQ because most women in the USA will take this GD test at some point, often without understanding fully what they are taking. More in depth information about the GD tests can be found in the FAQ on GD: Testing Protocols.
As with other forms of prenatal testing, it's important to note that not everyone agrees with the value of such testing, and some people decline it. It is certainly within your right to decline GD testing or arrange for alternative testing. Keep in mind, however, that some providers will drop you as a client if you choose to do this. There are other providers who will welcome you as a client even if you do not choose GD testing, but you may need to be willing to go outside the traditional medical model. There are options; only you can decide what to do in your own case.
Regardless of what you choose to do about GD testing, it is always wise to be very cautious in eating and exercise habits in pregnancy. Whether or not you take any form of GD test, look carefully into getting regular exercise (which can cut the risk of GD in half in larger women), and following a GD food plan (which may also lower the risk for developing GD) as much as possible in order to minimize your risks for getting GD. More information on possible prevention strategies can be found at GD: Can It Be Prevented? on this site.
About the 28th week of pregnancy, most providers (but not all) have the mother take the one-hour screening test for gestational diabetes. The test is given at about this time because most of the critical hormones that tend to raise blood sugar peak just before this time. The test may be given earlier if the mother is deemed to be in a 'higher-risk' group, such as certain ethnic groups like Hispanics or Native Americans.
Large women are also deemed to be at higher risk for GD, so they are often tested earlier in addition to the later test, although this is not absolutely required and may vary from practice to practice. The test may also be repeated in the third trimester for those deemed to be at extremely high risk for GD, since one other hormone (progesterone) peaks at about that time and may tip a borderline woman over into 'GD'. However, this practice of frequent testing is debatable (see below for further information).
If a woman "fails" the one-hour screening challenge, then she is usually sent in to take the three-hour diagnostic test. Most women who "fail" the one-hour test will pass the three-hour test, but of course, some women will also be diagnosed with GD.
Occasionally, some women can react to either the one-hour or the three-hour test and become very ill. The women who react like this usually tend to have hypoglycemia (low blood sugar reactions to lots of carbohydrates). For some women, these tests result in a headache, sleepiness, or vague nausea. Other women will actually vomit. A few who tend to have very strong reactive hypoglycemic reactions may even pass out.
These women may do better with an alternative test that does not involve drinking large amounts of sugar-saturated liquids (glucola). Although many doctors will not consider alternative tests, some will if you negotiate with them. More information about alternative tests can be found on this website under GD: Testing Protocols.
However, for most women in the USA, the testing protocol they will undergo involves a combination of the one-hour screening challenge and the three-hour glucose tolerance test (GTT).
The One-Hour Screening Challenge
The first test is simply a screen, designed only to find a group of women that need further testing. It does NOT mean that you have GD, only that you need another test! About 85% of the women who 'fail' the one-hour screening challenge test will actually 'pass' the three-hour diagnostic Glucose Tolerance Test, so don't panic if you 'fail' the first test. Chances are you will still 'pass' the second.
Only 15% or so of the women who 'failed' the initial screening test will also 'fail' the diagnostic test and be labeled as having 'gestational diabetes'. However, even if you 'pass' the second test, it would be appropriate to be more cautious in your food intake (much less sugar and refined carbs, limiting overall carbs at any one meal, more protein more often through the day, eating a small snack every 2-3 hours, more exercise, etc.). A failed screening test means that you are at somewhat increased risk for macrosomia (big baby); being extra careful with your nutrition may help mitigate this risk.
The most common screening test is the 50g Glucose Challenge Test. In this test, you are given a kind of 'soda-pop' (usually orange, cola, or lemon-lime flavored) which contains 50g of glucose. Basically, it is carbonated sugar-water with a little flavoring, more or less. You have to drink it down in 5 minutes or less.
After exactly one hour, blood will be drawn from your vein and the plasma tested to see how high your blood sugar is. A few offices use a hand glucose monitor instead, adjusted to read plasma-like results. Since hand-held glucometers are not always highly accurate, it is probably best to have results confirmed with an actual lab test.
If your results are >140 mg/dl, you are deemed to be in need of further testing. Because the cutoff of 140 mg/dl means that about 10% of GD cases will be missed, some providers routinely use a lower cutoff of 130-135 mg/dl. This is quite common. A few providers will use even lower cutoffs in the 120s, though this is extremely conservative and may only be applied to women thought to be at extra high risk, such as older women, heavy women, women with a history of diabetes in the family, or women from certain ethnic groups. However, this is rare, even in those groups.
Officially, the 50g challenge test is given without regard to the time of day, to when you have eaten, or any other circumstance. However, more and more providers are giving it in the fasting state. The idea is that then they can take two readings, the fasting glucose and then the 1 hour post-glucola reading, to see if either is abnormal.
A more subtle and insidious reason to do it in the fasting state is to catch more "abnormal" cases. When women fast for 8-12 hours, then suddenly have 50g of pure sugar dumped on their systems right at the time when pregnancy hormones fluctuate the highest (morning), there are more people with "abnormal" results. If you are a provider who believes that even mildly borderline readings are terribly risky and must be discovered and treated, then this makes sense. If you are a provider that believes that borderline numbers are not very meaningful and that the risks of treatment probably outweigh the risks of non-treatment in such borderline cases, then you will be less likely to do the test in a fasting state.
Kmom agrees with the latter opinion. In Kmom's personal view, it's probably best to take the test in the middle of the day, having had a healthy breakfast or lunch with plenty of protein, but having let at least 3 hours pass since you last ate. Officially it's not supposed to make any difference whether you just ate or not, but it only makes sense that if you are trying to process the 60g of lunch carbohydrates you just ate along with the 50g of the glucola drink, you might tend to have a higher test result. So, while you should never try to fool the test, it doesn't make sense to go in and take the test in a way that might raise your results falsely.
Before the test (and indeed all through your pregnancy) you should have been exercising on a regular basis and eating healthily. You should not take the test when you are ill, when you are greatly stressed, had a really bad night, etc. Many sources also advise women to avoid eating sugar in the days around the scheduled test.
Again, technically, the rules say that the 50g challenge test should be given without regard to any of these circumstances, but Kmom disagrees and feels that the test should NOT be given right after a meal, fasting, or when the mother is abnormally stressed or ill, since these will raise her results above normal levels and possibly force additional testing that might not have been needed.
However, neither should you try to 'trick' the test by suddenly running out and changing a bunch of habits. Your results should reflect your normal lifestyle and what presumably would be your normal blood glucose (bG) readings after food. This is very important--don't try to 'fool' the test. If you have poor habits, try to "fool" the test, and then go back to your poor habits, you may be putting your baby at risk. The test results should reflect your NORMAL pregnancy habits and lifestyle. This is very important.
The Three-Hour Diagnostic Test (GTT)
If your one-hour screening challenge results are above the cutoffs listed above, you will then be given the actual DIAGNOSTIC test, the three-hour 100g Glucose Tolerance Test (GTT). In this test, some authorities tell you to prepare by emphasizing carbohydrates in your diet for 3 days beforehand (carbo-loading), being active, and exercising normally. Then you fast overnight for 8-12 hours before the test. Only water is allowed during this fast, and the timing is very important too. Too short or too long a fast can skew the results.
At the lab, a fasting blood draw is taken. Then you are given the glucola to drink, only this time it has a 100g sugar load. You don't have to drink twice as much as the 50g test, they just use a super-saturated glucola which is twice as sweet. You have to drink it within 5 minutes.
Then your blood is drawn at timed intervals, most commonly after 1 hour, 2 hours, and 3 hours, although a few labs have some variations on this. The plasma is separated from the blood, and sent to the lab for testing.
Gestational Diabetes is diagnosed when two or more of the cutoffs are exceeded, unless the fasting is high in which case only that reading is needed to diagnose GD. Some providers will diagnose GD on the basis of just one elevated level, as these women are more at risk for macrosomia (big babies), but this is not a widely-accepted policy yet.
The scale used for determining the cutoffs varies from provider to provider; the American College of Obstetricians and Gynecologists lists 2 different scales of diagnostic cutoffs. The American Diabetes Association has long pushed for the stricter scale, and in the last couple of years, this is the scale that seems to be used more often. You have to ask your providers exactly which scale they use and why.
TESTING CUTOFF VALUES COMMONLY USED - 3-hour glucose tolerance test (100g)
| Reading | NDDG* Scale Cutoff | Carpenter/ADA** Scale (most common) |
| Fasting Draw | 105 mg/dl | 95 mg/dl |
| One Hour Draw | 190 mg/dl | 180 mg/dl |
| Two Hour Draw | 165 mg/dl | 155 mg/dl |
| Three Hour Draw | 145 mg/dl | 140 mg/dl |
*NDDG = National Diabetes Data Group
**ADA = American Diabetes Association
See the GD Testing section for further discussion of these various cutoffs and their pros and cons. Please note that the above numbers are written in the measurement scale used in the United States; if you live outside the US, you will need to divide these numbers by 18.
There are several important issues to be aware of in GD testing. With only a couple of exceptions, a two-tiered set of tests must be administered. However, there are occasions when this is not true and different protocols are used. Women should be aware of these. In addition, women should realize that many critics do not believe that the typical GD testing protocol is valid or reliable, and so dispute the many strong interventions which are based on what they view as dubious data.
Two-Tiered Test Protocol
In most cases, women need to undergo two different tests to be diagnosed with GD. The one-hour challenge is used to screen women and determine who should take the full 3 hour test, but it should NOT be used to diagnose GD. The 3-hour GTT is the only test that can diagnose the condition of gestational diabetes. If your doctor tries to treat you as having GD on the basis of your one-hour challenge test alone, you are being misdiagnosed. ONLY the GTT should be used to diagnose GD (with the exceptions noted below).
There have been cases in the past, particularly for large women, where the doctor gives the one-hour challenge test, the result is borderline, and the doctor diagnoses GD from that borderline or slightly high result and goes straight into treatment, skipping the 3-hour test. THIS IS INCORRECT TREATMENT. Except as noted below, the full three-hour GTT test must be given in order to diagnose GD.
Remember, only ~15% of the women who 'fail' the screen actually 'fail' the full GTT and end up being diagnosed with GD! So if any doctor tries to bulldoze you into a GD diagnosis without doing the full GTT, you need to find a new doctor, pronto! And especially so if he tries to justify it because you are in a 'higher-risk' category. The standards for diagnosis are the same, no matter the person's ethnicity, size, family history, etc.
Exceptions to the Rules
Of course, there are occasionally exceptions to every rule! There are two main exceptions to the rule that only the three-hour GTT can be used to diagnose GD.
The first exception is when there is a very high result on the one-hour challenge test. The cutoff is 140 mg/dl; if your results on the challenge were well over 200 mg/dl, it's safe to say that you have GD and should proceed directly to treatment. You will probably need insulin, too.
Some doctors have proposed a cutoff of 185 mg/dl for 'diagnosing' GD on the one-hour screening challenge; Kmom is not in agreement with this and feels women between 185 mg/dl-220 mg/dl should proceed with the GTT, since some women in this range test negative on the GTT with further testing. However, that's simply her opinion and not medical advice; some doctors would disagree with her. You can read more about this controversy in the websection on this site on GD Testing.
The second exception involves testing protocols outside the USA, which are not the same as in the USA. Most providers outside the US use one 75g two-hour test instead of the double test (50g screen and 100g GTT) used in the US. The advantage of this is that only one test is needed instead of two. This is a great advantage in third-world countries, in rural areas where it is difficult to get to the doctor, and when there are financial constraints that make covering two separate tests prohibitive.
Medical professionals have been arguing over the various testing protocols for years now. The reality at this time is that providers in the US generally use a 2-tiered testing system of a screen and diagnostic GTT, whereas those outside of the US generally use one 2-hour diagnostic GTT.
The two-hour 75g test is very much like the 100g GTT. The woman fasts for the test for 8-12 hours. She shows up in the morning to the lab, they take a fasting blood draw, then she drinks the glucola. The sugar load in this test is about 75g, halfway between the other two tests. Then the lab does a blood draw at two hours. Sometimes there is an extra draw at the half-hour and hour mark in some labs.
The cutoffs for diagnosing GD on the 75g GTT vary from provider to provider. The 4th International Workshop-Conference on GD has called for cutoffs of about 155 (8.6 mM) after 2 hours on this test, but this is a very conservative body that generally advocates very low cutoffs. Many providers differ, so you will have to consult your provider for his/her specific standards. Requirements for the 75g test are not standardized around the world and will vary widely.
Another exception to the two-tiered testing system occurs when a doctor waives taking the one-hour glucose challenge and has a woman proceed straight to the three-hour GTT. Some doctors will do this in women who have tested positive for GD in prior pregnancies, or who are at extremely high risk for GD (such as certain Native American tribes), etc.
It's important to note that the above exceptions are not likely to be encountered by most US women being tested for GD. Most US women will have the one-hour 50g challenge test, and if their results are around 140 mg/dl or more, they will have a follow-up diagnostic three-hour GTT with a load of 100g. In most practices, they will most likely be diagnosed with GD if their results exceed the ADA standards noted above.
Whether this is beneficial or even justified is a matter of significant debate, but this is the most common GD testing scenario in the USA today.
Questioning the Validity and Reliability of the GD Tests
Childbirth educator and author Henci Goer has strongly questioned the validity of the GD diagnosis in her excellent book, Obstetric Myths vs. Research Realities. She notes that the GD glucola tests are known to be very unreliable, and women can get different results on them on different days. Tests should be highly reproducible, meaning that they should get the same or very similar results despite being taken on different days or times. If a test is not very reproducible, then its usefulness is highly questionable, and very interventive treatment may be made on the basis of questionable data.
Enkin et al. also strongly question the use of GD tests in their book, A Guide to Effective Care in Pregnancy and Childbirth. They note:
The diagnosis of 'gestational diabetes', as currently defined, is based on an abnormal glucose-tolerance test. This test is not reproducible at least 50-70% of the time, and the increased risk of perinatal mortality and morbidity said to be associated with this 'condition' has been considerably overemphasized. As no clear improvement in perinatal mortality has been demonstrated with insulin treatment for gestational diabetes, screening of all pregnant women with glucose-tolerance testing is unlikely to make a significant impact on perinatal mortality or morbidity...The available data provide no evidence to support the wide recommendation that all pregnant women should be screened for 'gestational diabetes.'
Another valid concern is that the glucola tests exaggerate a woman's response and do not reflect a real-life situation. Rarely do women consume that much straight sugar outside of these tests (unless she drinks a lot of soda). Even when she does consume that amount of carbs, it is usually combined with fat and proteins, which even out and make her blood sugar reaction less volatile. Thus a woman may have an "abnormal" test result based on large amounts of glucola/straight sugar, but have perfectly normal blood sugars after meals.
There are a number of other concerns about the current gd testing protocols as well. These include:
There is great debate currently occurring over these concerns. More about this debate can be found in the FAQ on GD: Testing.
Glucose Testing and Large Women
In pregnancy, the cascade of hormones that effect blood glucose and insulin resistance generally peak between 26-32 weeks. It is important to find a time to test for GD that catches the majority of GD cases yet still allows adequate time for preventative treatment to head off potentially serious effects. Over the years, the most optimal testing time has been determined to be at about 28 weeks (end of the second trimester) for the majority of women, slightly earlier for women with a multiple pregnancy.
However, if there are special risk factors to consider (age, history of diabetes in family, ethnicity, and yes, obesity), then many doctors choose to administer this test multiple times. Some doctors choose to administer the test in the first trimester, second trimester, AND third trimester, and some doctors even choose to administer the test monthly, all the on the basis of the mother's size. Is this reasonable?
Early Testing for Big Moms
Many doctors require that big moms take the GD test in the first trimester as well as at 28 weeks. This seems sensible when multiple risk factors are present, but is it justified in large women if size is their only risk factor?
One argument for early testing in heavy women is that we do have higher rates of previously undiagnosed diabetes. Most of us will test negative, but the the women who have unidentified pre-existing diabetes from before pregnancy are in such a high-risk category that most doctors feel this justifies early testing for the whole group. Their view is that high blood sugar can do so much damage at this early stage that the trade-off of unnecessary testing for most large women may be worthwhile.
This problem can be avoided if women just have their blood sugar tested BEFORE pregnancy to establish that they are non-diabetic. If women establish that they are non-diabetic and have great blood sugars before pregnancy even starts, this takes away the concern for detecting undiagnosed true diabetes and the most compelling reason for early testing.
However, it's also possible for a woman who is normoglycemic before pregnancy to develop severe GD early in the pregnancy. This is unusual; usually early GD develops in women who were borderline prior to pregnancy anyhow, but it is possible even in women who were not borderline. The argument here is that if severe GD is already present in early pregnancy, it puts the fetus at significant risk, the GD will worsen as time goes on, and preventive treatments and monitoring may be very important for the baby's health. This is a good argument.
The problem is that MOST large women won't test positive for GD early in pregnancy and all that testing and monitoring is burdensome. It is also probably not healthy to be dumping all that sugar into the system of a mom in early pregnancy, and certainly doing the testing is stressful in many ways. It also psychologically makes the woman appear to be high-risk (even when she's not), both to herself and to her doctor, and may lead to further unnecessary interventions.
On the other hand, early testing may catch a few cases of severe early GD, which would probably greatly benefit those babies and mothers. So it's a tough call. Burdensome testing for all for the benefit of a few; one of the most common obstetric dilemmas these days.
Early testing for GD in women with multiple risk factors clearly seems justified. If the mom is a large woman from a family with a history of diabetes and has PCOS, she should probably be tested, for example. But what about the big mom whose only risk factor is her size?
This is a tough call. Early testing may catch a few cases of undiagnosed diabetes or severe early GD, but for most women it is a long and arduous testing process that will turn out to be totally unnecessary. In addition, given the weaknesses of the test and its notorious lack of reliability, it's difficult to recommend this test at ANY time, let alone when it is probably unnecessary.
Kmom's personal opinion is that early testing is justified in the presence of multiple risk factors for GD. (See the FAQ on GD: Risk Factors for more information on these risk factors.) In women whose only significant risk factor is obesity, however, the test is usually unnecessary and burdensome. Yet some testing in some situations may be prudent.
Common sense helps in making a testing decision such as this. Providers may choose to look at a woman's overall lifestyle and habits when deciding whether or not to test. For example, if the mom has great nutrition and gets regular exercise, testing probably isn't as necessary. If the mom has lousy nutrition and never exercises, testing is probably important.
Most providers these days will probably want some kind of assurance that a big mom's blood sugar is normal. Given their burdens of liability, that seems reasonable, within the bounds of common sense. But unfortunately the provider's need to prove a normal pregnancy for legal reasons tends to take precedence over common sense use of tests, and many big women are made miserable by having to take these tests again and again. This is also unreasonable.
In Kmom's opinion, some kind of compromise should be worked out whenever possible. Big women can elect to either take the glucose challenge test early in pregnancy if they don't mind it, or work out another plan to address risk factors and concerns. If the mom is willing to receive GD food plan nutritional counseling and follow a GD-like plan, then further testing can probably be delayed.
If the mom is willing to have alternative testing, like a fasting and/or post-meal reading, that is also a reasonable choice. This would show any women with abnormal results while avoiding dumping so much sugar on the pregnant woman's system. This kind of testing may be best for women who react badly to glucola tests (like hypoglycemics), but the down side is that it may need to be repeated more than once. Still, for many women, this alternative is preferable to throwing up from the glucola tests.
Some providers are willing to use jelly beans instead of glucola. Two studies have found that jelly bean testing is as accurate as glucola testing (although diagnostic cutoffs may need to be adjusted), and that women tolerate the jelly beans much better than the glucola. Most OBs currently resist the idea of jellybean testing, but some doctors and midwives are open to the idea, especially if the woman has had bad reactions to glucola tests in the past. Some midwives will also consent to using juice instead of glucola, which many women also tolerate better than glucola.
Other women (for example, those with a past history of GD) may be willing to follow a GD food plan and do daily or periodic testing of their blood sugar on a home glucometer instead of taking the whole battery of glucola tests again. This makes a great deal of sense; it shows that the mother's blood sugar is normal on a REGULAR basis (which is more than the glucola tests show), and it does not dump a large amount of pure sugar into the mother's system, making her and her baby sick.
Each big mom must decide for herself how important this issue is to her. If she finds taking the one-hour glucola challenge to be no big deal, then she may not have any real objections to taking it in the first trimester and again in the second. If she knows ahead of time that she tends towards hypoglycemia and blood sugar crashes, she might want to negotiate with her provider for a different form of the test. If the big mom knows that her nutrition is great, she is exercising regularly, and that she has no family history of diabetes, she might choose not to take the GD test at all in the first trimester. Other moms may negotiate periodic monitoring of their fasting and post-meal blood sugars instead of taking the full battery of glucola tests. Each mom must work out the best protocol for herself with her provider.
Testing in the Third Trimester in Women of Size
Some providers demand that big moms not only test in the first trimester and the second trimester, but also again in the third trimester. The reasoning behind this is that although 4 of the 5 most diabetogenic hormones peak at about 26-28 weeks (and so testing then picks up most cases), the fifth hormone (progesterone) does not peak until about week 32.
Because of this, there are a few women who test negative for GD in the first and second trimester but test positive for GD in the third trimester. Just how much of a potential problem this is is not clear, but because most OBs view GD from a place of fear, they order extra testing in the third trimester. Fortunately, it is not likely that you will get GD from one more "peak" of hormones if you have already tested negative with 4/5 of the diabetogenic hormones earlier.
However, testing in the third trimester may be more justifiable in a woman whose earlier test results were borderline, especially if she has a strong family history of diabetes or other strong risk factors. If you have consistently tested high on the glucose challenge and barely passed the three hour GTT previously in the pregnancy, then perhaps additional testing in the third trimester is appropriate.
On the other hand, perhaps it does not need to be the burdensome full GTT. Perhaps periodic fasting and post-meal testing would be more acceptable, or some women may be willing to take home a glucometer and do some periodic home testing under real-life conditions. Other women may prefer to go with the one-time GTT instead. Again, providers should be flexible and willing to negotiate.
But what about a big woman whose prior GD test results have been totally normal, not borderline at all? Is there a need to test her in the third trimester, simply because of her size? In Kmom's opinion this is totally unnecessary and inappropriate. If the prior test results have been excellent, there is no need to repeat the test again just because of a woman's size.
If you doctor insists that you MUST repeat the test in the third trimester despite excellent results in the past, this is another clue that your doctor is fat-phobic and doesn't believe you can have a normal pregnancy and birth. If you have other risk factors or borderline results that may make another test more justifiable, fine. But if you do not and they are testing solely because of your size alone, this says a great deal about that provider's beliefs and mistrust. In Kmom's personal opinion, you should seriously consider whether or not you should continue with this provider.
Extremely Frequent Testing in Women of Size
Some providers have the attitude that if you are large, you will get gestational diabetes and it's only a matter of time until you do. Despite research showing that most large women actually do NOT get GD, these doctors think that MOST large women do get it. These size-phobic providers are the ones who demand constant GD testing in order to catch the "inevitable" GD immediately.
These providers view big women to be at such high risk that they feel constantly on edge having a big mom in their practice. To compensate for their anxiety, they feel compelled to overmonitor. Kmom has heard from big moms who were forced to take the glucola tests EVERY MONTH, or four or five times in a pregnancy, despite always excellent test results. This is outrageous and totally unnecessary.
The fact is that while we do have somewhat higher rates of GD, the majority of large women do not actually get GD (only 1 of 5 get GD in one study; even less in another study). Because a significant percentage do get GD, it is important to do some testing and/or nutritional counseling, but because most do NOT get GD, it is not justifiable to keep testing constantly. Striking a balance between monitoring 'just in case' and yet not over-monitoring is important.
There is no need to test larger women constantly. If a provider insists on extremely frequent testing, this is a DEFINITE sign that he/she is fat-phobic, views you as tremendously high-risk, and will never give you decent and fair care. Any woman who is pressured to take extra tests like this should STRONGLY consider switching providers, as this one is likely to railroad you straight into a bunch of unnecessary interventions, a premature delivery, and quite likely, a cesarean, and will make you feel as badly as possible while he's doing it.
Be assertive and don't stand for unreasonable, sizist care. Find a new provider. It is NEVER too late to switch providers. And it's worth it to protect yourself and your baby from sizist, interventionist care.
So What Is a Reasonable Testing Regime?
There are no DEFINITIVE testing regimes for GD. Given the criticisms of the tests and the inability of treatment to substantially improve fetal outcome, doing any testing at all is still a questionable proposition. However, the reality in the United States is that most providers want to do some GD testing, and particularly so in larger women. Working out a testing compromise is likely to occur in most care situations here.
Each woman's situation and risk factors has to be considered individually. Rigid, across-the-board protocols generally work against women of size and cause a lot of burdensome extra testing and anxiety. Instead, women and their providers should negotiate and work out a compromise that seems reasonable and workable to them.
Is GD testing absolutely mandatory? No. Some providers do not require GD testing at all, because they view GD as a highly questionable diagnosis and most treatment as more harmful than helpful. Homebirth midwives are most likely to have this viewpoint in the USA; many OBs and other doctors and midwives outside of the USA also believe in this viewpoint. So GD testing is not absolutely mandatory everywhere, and that is true for women of size too.
If women have multiple risk factors for GD, however, some testing is reasonable. Once in the first trimester and then again at 28 weeks seems reasonable. If these tests are borderline at all, another follow-up test at 32 weeks may also be reasonable. However, even in this situation, many women are able to negotiate for different testing or more flexibility.
In women of size with no other risk factors, testing protocols should be flexible and worked out between the mother and her provider. Some women will consent to take the 50g, one-hour test, while others (especially those with a tendency towards low blood sugar reactions) will want to work out alternative testing, such as periodic fasting and post-meal checks.
For women whose previous test results were fine, testing yet again in the third trimester is overkill and unnecessary, regardless of size. For women whose previous tests were negative but borderline or who have extremely strong risk factors, a further test in the third trimester might be justified, but it should not be made on the basis of size alone. Size should not be the determining factor in selecting a further test, though it may be a contributing factor along with other considerations. Judgment must be made on a case-by-case basis.
Finding Out Your Results
After the test, your provider should call you with your lab results. Be aware that the lab technicians are not supposed to inform you of your test results while you are taking the test. The numbers are supposed to come from your providers, although sometimes some lab techs can be talked into revealing your results the day of the test. Most of the time, though, they won't reveal the results or don't know the results themselves. In many labs, the techs just collect the blood, store it, and send it elsewhere for testing.
If you own your own home glucometer (or if someone you know owns one), you can take this along and test yourself as you get the official blood draws. Keep in mind, however, that most home glucometers are testing capillary blood, while the official lab uses venous blood, and separates out the plasma for the real testing.
Plasma results generally run 10-15% above capillary blood results, so remember that the lab results you receive in a few days may be higher than the numbers you see on your glucometer. There are now SOME glucometers that have been adjusted to show "plasma-like" readings, so it's possible that the readings may be close. But be aware of the possibility that the two numbers may not match exactly. Your provider will go with the lab result over the glucometer result.
There is no exact timeline for the lab results to come back; it can take anywhere from a couple of days to a week or two. Remember that the blood collection lab has to send them to the blood testing lab, which has to test them and generate a report, which then has to be sent to the doctor's office, which then has to be entered into your chart, and then someone has to find the time to call you about them. It can take a while!
Get Your Exact Results
When your provider calls you with your lab results, ASK FOR YOUR EXACT RESULTS ON EACH TEST. This is very important! Most of the time, patients don't care what their results are, they just want to know if there's a problem or not. So most doctors have grown used to simply telling women that their tests were "normal" or "abnormal." They won't think to tell you exact numbers unless you ask.
However, you want to know your EXACT results, whether or not they were normal! This can be very informative for you to know, however they turn out, so Kmom strongly recommends getting the exact numbers and writing them down. Some women request a copy of their lab slip, which is certainly within their right, although sometimes doctors resist doing this. These are YOUR records; the doctor keeps the original but you have every right to have a copy for your records. Legally, they are required to give you a copy of your records.
Be sure you not only find out your exact numbers, but also which diagnostic scale was used to determine whether or not you had GD. For example, you might find that you have GD by the ADA scale but not by the NDDG scale. This can be useful information to know.
Why would you want to know exact numbers if your results are normal? Because you want to see HOW normal they are. For example, the fasting cutoff under the ADA standards is 95. If your number is 93 or 94, you know that you just missed the cutoff and will need to be more aggressive about good nutrition and exercise. If your fasting was 77, on the other hand, you may not need to be so strict.
Also you want to know if there is any tendency towards higher numbers after the glucola. Some women can have perfectly normal fasting numbers but have high responses to food. If any of your 1 hour, 2 hour, or 3 hour numbers are borderline, you know you need to be very strict about the amount and type of carbs you eat in your meals from now on. If these numbers are excellent and not even close, you may not need to be as strict, although good nutrition and common sense should always be a priority.
Okay, so why find out exact numbers if your results are abnormal and you are diagnosed with GD? Because you want to see HOW abnormal they are, and what the pattern of greatest abnormality is. If your numbers are barely over the cutoffs, then you will probably have good luck controlling your blood sugar by diet alone. If your numbers are way over the cutoffs, you know you are going to have to be very strict with eating and may even need insulin.
If your numbers diagnose "GD" by the ADA scale but not the NDDG scale, then you know that with another practice, you might not have this label of GD. Some women who believe that borderline GD is not risky and that diagnosis often brings more risk than benefit might want to switch to a provider that is less strict about diagnostic cutoffs. Other women may want to stay with their present provider but remember that their risk of complications is probably lower than the mom with truly high GD results. This may help them negotiate with their provider for less interventions.
You also want to find out your exact numbers so that you'll know when your greatest abnormal numbers seem to occur. If your fastings are high, you want to know how high to see if you'll need to be on insulin, and to try a few things to get those fasting numbers down (see GD: Troubleshooting High Numbers for ideas).
If your one-hour is high, then you'll know you need to test one hour after your meals when you are on your GD food plan. If your two-hour is high, this may raise your risk for certain outcomes such as macrosomia (see the GD: Testing FAQ for details), and that you'll want to test your blood sugar two hours after meals.
If your one-hour is sky-high and then your three-hour result crashes down really low, this indicates you have a tendency towards reactive hypoglycemia. This is handy to know because more frequent protein/less carbs may be the best treatment, and you will also know that you may have to watch carefully for hypoglycemic reactions.
Knowing your EXACT numbers can help you better understand your GD risks, treatment needs, and possible interventions. They are also a valuable record to have for the future, as you consider your risk for diabetes in the future, or in future pregnancies. Even after the pregnancy is over, KEEP THE RECORD OF THE RESULTS.
If You Are Not Diagnosed With Gestational Diabetes
If you do not have gestational diabetes, congratulations! This is great news. Take a moment to celebrate and relax.
But remember, this doesn't mean you should become lax in your eating habits and slack off of exercising. Sometimes women pass the GD test and then go out and celebrate excessively, indulging in foods that are not healthy in pregnancy no matter what your test results are.
Although GD develops most commonly at around 28 weeks or so, it can theoretically develop at any time. Even if you test negative at 28 weeks, you should still be cautious in your eating and exercising. Pregnancy hormones do increase as the pregnancy goes on, and it is these hormones that cause the insulin resistance that is behind most GD. Therefore, caution is still prudent, all through pregnancy, whether or not your provider requires further testing. Don't think of a passed GD test as an excuse for overindulging from then on.
In particular, you should be extra cautious if you had a positive screening test (one hour) for GD but tested negative on the 3-hour GTT. Research shows you are still at risk for a big baby (macrosomia), even though you don't officially have GD. Therefore, you should be particularly careful about your nutrition and your exercise levels, which may help lower your risk for macrosomia.
In this situation, you should probably also consider limiting your carbs, avoiding highly refined food and sugar, "grazing" on smaller but more frequent meals, and combining carbs with protein and fat, like you would on a GD food plan. Keep in mind that this is NOT a diet, only a way of spreading out your food and combining it in a way that keeps your blood sugar as low and as even as possible. For some women, this is enough to lower their risk of macrosomia.
Chances are very good that everything will be fine regardless of what you do, but it only makes sense to continue to be cautious even though you have passed your GD tests. ALL pregnant women should be practicing excellent nutrition and sensible exercising. Passing the GD test should not be seen as an excuse not to do that. Your baby still needs you to be healthy for him. Keep up the good work!
If You Are Diagnosed With Gestational Diabetes
If you have been diagnosed with gestational diabetes, you should realize that it's not the end of the world! Chances are everything will be fine and you just need to be more careful about your food and exercise. Many women have been on this path before you and have done just fine. You can do it too!
It's normal to be upset and to have lots of mixed feelings about this diagnosis, but in time you will learn to deal with things. Chances are very good that if you take care, your baby will be healthy and will be born just fine.
However, it's also important to realize that you are going to need to do some research about GD so that you can know more about your treatment choices. Providers vary TREMENDOUSLY in their treatment protocols for GD, and the recommendations you will be given for your care from your provider might well be completely different from the recommendations you would get from a different provider. At this time, little is written in stone about GD treatment. This means that it's very important to be well-read on the subject.
If you have been diagnosed with GD, it would behoove you to research the issues around GD so that you can participate in your own care decisions. Resources for doing more research can be found on this website, where there are also links to a number of other sites and to PubMed for you to do your own research.
You can get started on the process of familiarizing yourself with GD issues by reading the following sections on this website:
Don't forget to also access the many other websites dealing with gestational diabetes elsewhere on the Internet. It's important to research more than one point of view. Read many different resources and opinions so that you can make your care decisions from the most informed place possible. This website can be a good starting place, but it should never be your only source of information and opinion.
In the United States, it is standard to test for GD at about 26-28 weeks of pregnancy. Most providers have you take the one-hour 50g glucola challenge test in order to screen for those women who are borderline and need further testing. If your screen results are higher than ~140 mg/dl, they will send you for the three-hour diagnostic Glucose Tolerance Test (GTT). If these results are abnormal, you will be diagnosed as having GD.
GD is a controversial diagnosis, although most doctors in the US do not treat it so. In many countries it is not even tested for, or only tested for when other indicators point to the need for it. Many researchers have strongly questioned the glucola tests, since research has not shown them to be very reproducible (i.e., on one day you may test positive for GD and on another day you may not). This is a very valid criticism of the test, and is more fully covered in the websection on GD: Testing Protocols on this site. Also covered in that FAQ are the possible alternative tests that you can take if the glucola test makes you ill or you do not find it a suitably valid test.
Reliable test or not, the reality is that MOST doctors in the US feel that GD is real, and that MOST doctors in the US use the one-hour/three-hour testing protocol. Elsewhere in the world, the two-hour test may be used instead, so that women only have to take one test total. Whichever test you take, understand carefully the protocols your doctor or midwife wants you to use to take the test. Understand whether or not you have to fast, how long it should have been since you last ate, whether or not you need to follow a special diet before testing, etc.
When you receive your test results, be SURE to get your EXACT results, not just whether or not your results were normal. Also be sure you know which diagnostic scale they were using. Knowing your exact results enables you to determine where the problems tend to be, and may even help you change your treatment strategies. Keep a record of these results permanently, far beyond this pregnancy. It may help you in the future to know your exact results.
If you are not diagnosed with GD, congratulations! Keep up the good work; don't use your "passing grade" as an excuse for indulging. Babies need excellent nutrition all pregnancy long, so don't slack off. If you "failed" the one-hour test only to pass the three-hour test later, remember that extra caution with eating and exercise habits may be especially prudent in order to minimize the risk for macrosomia (big baby).
If you are diagnosed with GD, remember that this is not the end of the world, that you and baby most likely will be just fine, and that you can handle all the treatment, whatever that entails. Many other women have done this before you; you can do it too.
If you are diagnosed with GD, start reading up about typical treatment protocols and interventions. In particular, pay close attention to the controversies of GD treatment, as many things that are commonly done are not necessarily required or even beneficial. Become a partner in your own care; read up about GD and discuss the pertinent issues with your doctor or midwife. Remember that GD as it is currently thought of is a fairly modern diagnosis and that research is still establishing the best way to treat it, if indeed it needs to be treated at all in some cases. Become familiar with the controversies so that you can advocate for yourself and for your baby.
There are many websites out there that discuss GD and treatment choices. This website has many you can start with in the All About GD web section. Other websites can be found with an online search, or through the links provided from this website.
Kmom's GD Story: A Bittersweet Diagnosis
Kmom's Story: I was diagnosed with GD in my first pregnancy (not my second or third pregnancies, however). Because of my size and the lack of family history from being adopted, they assumed I was very high risk for GD and tested me early in pregnancy, but gave me very little information about the test and how to take it. The screen came back slightly below the cutoff so to be cautious they ordered the full 3-hour test. They didn't bother to tell me it was a fasting test this time so I had to reschedule and come back yet another time. The test itself made me quite ill, but at least I 'passed' it.
At that point, given my borderline results, they should have offered me some nutritional advice to help me lessen my risk of getting GD later on, but nothing was said. I had been experiencing severe morning sickness; I was told that it didn't matter if I didn't eat when I felt nauseous. This made my blood sugars start to swing greatly, increasing my nausea and probably predisposing me to greater blood sugar abnormality. I believe strongly that with a little more nutritional guidance I might have avoided getting GD later on. This lack of emphasis on prevention is a very sore point for me, considering everything that the 'GD' label led to for me.
In the second trimester, I retook the screening test. Once again I had no instructions on it, and took it during a time of great stress (I was packing up my house and job to move, plus I was sick). Again the results were borderline (just slightly above the cutoff this time), so again I took the 3 hour GTT. This time I knew to fast, but I didn't know that illness could affect the test. So I took the 3 hour test while I was sick, stressed, and after having been at 2 baby showers that week, complete with cake and punch---more sugar than I normally consume. I failed the 3 hour test this time, but it's hard to say whether those results were really reflective of my true condition or not. The stress, extra sugar, and especially the illness may well have made my results higher than normal.
I was diagnosed with GD, put on a special food plan, and nearly put on insulin as I tried to cope with all of this while moving to a new state and being majorly stressed out. Fortunately my blood sugar settled to normal once I got established in my new place and my stress dropped off. However, my pregnancy was now labeled as 'high-risk' and most OBs I interviewed wanted to induce early. I chose the only OB who would 'let' me go to term, and he induced right at 40 weeks, even though my cervix was not ripe.
The mere label of 'GD' made them induce, which led to a long rough labor and then a horrible cesarean, put all kinds of restrictions on me, made them give my baby formula (even when she didn't need it) leading to problems with breastfeeding, and made them 'see' problems in the baby that she didn't even have, leading to even more separation. It led to a GREAT deal of unnecessary intervention and almost totally derailed breastfeeding entirely. This is why critics charge that GD treatment can do more harm than good at times.
In subsequent pregnancies I tested negative for GD, despite being near 40. I made some changes to diet and exercise the next two times, plus I didn't take the tests while being sick! I was told by all the OBs that it was almost certain that I'd have GD recur again, and yet by being cautious and proactive, I was able to test completely normal. I wonder if I'd had more guidance in the first pregnancy whether I could have avoided all the interventions and worry and problems in the first place! That's a very frustrating thought. Although I think GD can be real and should not be lightly dismissed, I also believe that it is often over-diagnosed and over-treated, leading to many unnecessary iatrogenic (doctor-caused) complications.
In some ways the 'GD' was a gift because it helped me refocus my attention on my health (I did not choose to diet or intentionally lose weight, just became more careful about carb totals and types and in increasing veggies and fruits). It also alerted me to watch for diabetes outside of pregnancy so if I get it, I can catch it early before it does much damage.
However, in other ways it was really unhelpful, since it labeled my pregnancy as high-risk unnecessarily, and probably led to my c-section, which was a terrible experience. It also caused a great deal more fear and lack of confidence in myself in an already fearful pregnancy (from other prenatal tests). The implications are also life-long; I was turned down in my third pregnancy for life insurance because of a past history of GD, even though I didn't have it in any other pregnancy and despite the fact that all other subsequent tests have been normal. This is ridiculous, but they stated it was because of the GD. That stupid 'GD' label can follow you around for life.
If 'GD' really is a "diagnosis in search of a disease" (as some critics contend), and my borderline blood sugars really weren't a risk, I certainly paid a nasty price, and unnecessarily too. On the other hand, if even borderline blood sugars really are a risk and they can be helped by treatment (the jury is still out on this), then the screening and diagnosis was probably helpful in the long run. And I do have an early warning system in place for possible risk of full-blown diabetes in the future, which may help, but it has also added a great deal of worry and anxiety over that to my life as well. At this point, it's hard to tell whether the GD testing was really necessary and a good thing. However, it certainly was administered poorly, and I was not told how to take the test properly, which may have changed my results.
The point here is that not all providers agree on the value of the GD tests or even the GD diagnosis, so some women chose to take the tests and some women don't. Furthermore, the tests are not terribly reliable and can be affected by a number of outside influences like nicotine, illness, stress, etc. The screen test probably should not be taken right after a meal (in my opinion, wait 3+ hours after a meal to take it) so it does not measure both the meal carbs AND the test carbs. And different providers use different cutoffs for the 3 hour test, meaning that with same results you might get diagnosed with GD by one provider and not by another. In addition, women who get sick from the tests may want to explore the possibility of using an alternative form of test. Some providers are open to the possibility of using other forms of testing instead, and a few providers are okay with skipping the test altogether.
There's a great deal of controversy over gestational diabetes in general, and in particular over the testing regimens used for it. Mothers would do well to research the issue more carefully before taking the test, and the GD: Testing section on this website may help you with this research. It also has numerous references for further exploration of the issue.
American Diabetes Association Position Statement: Gestational Diabetes Mellitus. Diabetes Care. Volume 21: Supplement 1, 1998. http://www.diabetes.org/diabetescare/supplement198/s60.htm
Official 1998 position statement on the definition, detection, diagnosis, and therapeutic strategies for GD.
Carr, DB and Gabbe, S. Gestational Diabetes: Detection, Management, and Implications. Clinical Diabetes. Jan-Feb, 1998. 16(1):4-24. http://www.diabetes.org/clinicaldiabetes/v16n1j-f98/pg4.htm
Outstanding article summarizing GD testing, management, and even some of the controversies involved in GD, though from a traditional medical approach. Excellent overview, but very technical.
Stephenson, M.J. Gestational Diabetes Mellitus. Canadian Family Physician. 39:745-8, April 1993.
A must-read article for those serious about understanding GD treatment options. Covers fairly both philosophies of treatment, both the maximum and minimum schools of management. An excellent overview of the controversies.
Diabetes and Pregnancy, ACOG Technical Bulletin (An Educational Aid to Obstetrician-Gynecologists).
The definitive summary from the American College of Obstetricians and Gynecologists for pre-existing diabetes in pregnancy as well as gestational diabetes. Technical but readable. Represents the current standard of care.
Proceedings of the Fourth International Workshop-Conference on Gestational Diabetes Mellitus. Diabetes Care. August 1998. Volume 21 (Supplement 2). http://www.diabetes.org/DiabetesCare/Supplement298/B161.htm
The entire issue of this Diabetes Care journal is devoted to the recommendations and papers from the 4th International Conference on GD. Many important issues are discussed. Very conservative views; tends to conveniently ignore the criticisms and studies that contradict their conclusions. One-sided but still valuable.
Jovanovic-Peterson, Lois, M.D. with Morton B. Stone. Managing Your Gestational Diabetes. Minneapolis: Chronimed Publishing, 1994. To order, write P.O. Box 59032, Minneapolis, MN 55459-9686, or call 1-800-848-2793.
A good introduction to GD issues by one of the leading researchers in the field, who also happens to be diabetic (Type I) and a mother herself. Treatment guidelines in this book are quite conservative and her writings contain some patronizing and fat-phobic statements. Good introduction to the conservative approach to GD. She is a very prolific writer in the field; many more items are available under her name.
Gestational Diabetes: What to Expect. The American Diabetes Association, Inc. Alexandria, Virginia: American Diabetes Association, 1992. To order, write to the ADA, 1970 Chain Bridge Road, McLean, VA 22109-0592, or call 1-800-232-3472. Third Edition (revised in 1997) now available also.
The standard intro to the subject, written by the leading authorities on diabetes. A good, easy-to-read summary of the standard medical approach to GD, very conservative in guidelines, with no discussion of GD controversies.
Goer, Henci. Obstetric Myths vs. Research Realities. Westport, Connecticut: Bergin and Garvey, 1995. Can be ordered online from http://www.efn.org/~djz/birth/obmyth/
This excellent book reviews common obstetrical practices and analyzes which practices are truly justified by medical research. The Gestational Diabetes chapter examines the history of its treatment, and variations in protocols. She extensively reviews the medical research available on GD and concludes that many common GD protocols are questionable because they do not sufficiently alter outcome but did increase the incidence of cesarean sections and resulting complications. A must-read.
Goer, Henci. "Gestational Diabetes: The Emperor Has No Clothes." Birth Gazette. Spring 1996: Volume 12, Number 2.
A shorter summary of the GD chapter from the above book. www.gentlebirth.org/archives/GDhgoer.html.
Walkinshaw S.A. Dietary Regulation for 'Gestational Diabetes'. In: Neilson JP, Crowther CA, Hodnett ED, Hofmeyr GJ (eds.) Pregnancy and Childbirth Module of The Cochrane Database of Systematic Reviews, [updated 01 September 1997]. Available in The Cochrane Library [database on disk and CDROM]. The Cochrane Collaboration; Issue 4. Oxford: Update Software; 1997. Updated quarterly. Abstract available from www.cochrane.org.
A review of previous studies that examined dietary treatment vs. no treatment for GD. Concludes that studies do not support the value of primary dietary treatment for GD, but cites a number of methodological problems with previous studies and notes the need for further research with better research design.
Enkin, Murray et al. A Guide to Effective Care in Pregnancy and Childbirth. Third Edition. Oxford: Oxford University Press (Oxford Medical Publications), 2000.
Based on the Cochrane Database of Systematic Reviews, which examined the research of 60 key journals, with an emphasis on the 'gold standard' of research, randomized controlled studies. "Evidence-Based Medicine" at its best. Found significant reason to question the current aggressive approach to GD. "There is no convincing evidence that treatment of women with an abnormal glucose tolerance test will reduce perinatal mortality or morbidity. Trials of dietary regulation... do not demonstrate a significant effect on any outcome, with the possible exception of macrosomia. Trials comparing the use of insulin plus diet with diet alone show a decrease in macrosomia, but no significant effect on other outcomes such as use of caesarean section, the incidence of shoulder dystocia, or perinatal mortality. There is also no evidence that such treatment reduces the incidence of neonatal jaundice or hypoglycemia."
They further go on to make the very strong statement that "The available data provide no evidence to support the wide recommendation that all pregnant women should be screened for 'gestational diabetes,' let alone that they should be treated with insulin. Until the risks of minor elevations of glucose during pregnancy have been established in appropriately conducted trials, therapy based on this diagnosis must be critically reviewed. The use of injectible therapy on the basis of the available data is highly contentious, and in many other fields of medical practice such aggressive therapy without proven benefit would be considered unethical."
Blank A., Grave G.D., Metzger B.E. Effects of Gestational Diabetes on Perinatal Morbidity Reassessed. Report of the International Workshop on Adverse Perinatal Outcomes of Gestational Diabetes Mellitus, December 3-4, 1992. Diabetes Care. 18(1):127-9, January 1995.
Report of some of the findings from the Third International Workshop on GDM. (The Fourth took place in 1997.) A quick summary of some of the perinatal morbidities associated with GD and the serious concerns they may present; notable for acknowledging some of the research controversies such as possible alternative causes for some of the problems, the problems with reproducibility of GD testing, the lack of cost-effectiveness of aggressively trying to reduce macrosomia on a wide scale, and the problems with research design and data of previous studies. Strongly promotes the need for further well-designed research done on a multi-center, multi-ethnic, and multi-national long-term scale.
O'Brien, ME and Gilson, G. Detection and Management of Gestational Diabetes in an Out-of-Hospital Birth Center. Journal of Nurse-Midwifery. 32(2):79-84. March/April, 1987.
Describes a pilot program to treat mild gestational diabetics in an out-of-hospital birth center. Treatment was by nurse-midwives in consultation with physician consultants (severe cases were transferred to the OB). The population served was 95% Hispanic; the incidence of GD was 10%. The c-section rate for the clients treated by midwives was 9%; if the clients transferred to OB care and had c-sections, the midwives' c/s rate was 11%. It is important to note that this rate was MUCH lower than the c-section rates reported by many other studies, which on average range between 20% and 35%, but in some studies have reached even higher.
Javanovic-Peterson, Lois, M.D. The Diagnosis and Management of Gestational Diabetes Mellitus. Clinical Diabetes. pp32-39, March/April 1995.
A very technical journal article covering basic GD information in great detail, including information on hormonal influences. Very conservative guidelines for insulin, and recommends strong caloric restrictions for 'morbidly obese' patients. Very dense reading, but good for those wanting more insight on the conservative view of GD.
Weller, KA. Diagnosis and Management of Gestational Diabetes. American Family Physician. 53(6):2053-7, 2061-2. May 1, 1996.
A review of GD treatment regimens, though it tends to be much less intervention-oriented than many treatment regimens found in endocrinology and obstetrics literature.
Jackson, E.A. et al. Management of Gestational Diabetes by Family Physicians and Obstetricians. Journal of Family Practice. 43(4):383-8, October 1996.
The charts of 813 women with GD were retrospectively examined to see if management practices and outcomes differed between family practice doctors and obstetricians. 33% of OB patients were placed on insulin, while only 24% of FP patients were placed on insulin, even though patients exhibited similar demographics of body mass index, weight gain, gestational week at entrance to care, etc. Even more striking was the difference in c-section rates----OB patients had a c-section rate of 33% while family practice patients had a c-section rate of only 11%. There were no significant differences in neonatal outcome (including macrosomia) between the two groups, despite treatment differences.
Hod, M et al. Gestational Diabetes: Is It a Clinical Entity? Diabetes Reviews. 3(4):602-613, 1995.
A review of the debate over whether GD is really a problem, with a strongly affirmative conclusion about the dangers of GD and the effectiveness of treatment. Advocates lowering treatment thresholds even further. Has the most astounding list of newborn treatment protocols, and some of the most extensive prenatal treatment protocols for the mother, too. Extremely conservative view of GD and GD treatment.
Keen, Harry. Gestational Diabetes: Can Epidemiology Help? Diabetes. December 1991. Volume 40, Supplement 2: 3-7.
Examines some of the history of diabetes and GD diagnosis, with special attention to the problems of a borderline range between normal and clearly diabetic. Notes that severe GD clearly needs treatment but that "there is much less certainty about the hazards, if any, associated with the lesser degrees of glucose intolerance...Attention is drawn to the paucity of evidence linking lesser degrees of glucose intolerance with significant disturbance of pregnancy outcome when confounding variables such as maternal age, adiposity, and parity are allowed for. It is in the area of the detection and treatment of these lesser degrees of glucose intolerance in pregnancy that serious questions of the detriment-to-benefit ratio arise. A population-based multiethnic multicultural inquiry into diagnostic methodology and criteria in pregnancy is proposed...extending...to a controlled clinical trial of the effects of intervention." A fair and unbiased overview of the controversy, history, and implications of GD. Adequately represents both sides. HIGHLY recommended reading.
Nordlander, E et al. Factors Influencing Neonatal Morbidity in Gestational Diabetic Pregnancy. British Journal of Obstetrics and Gynecology. June 1989. 96(6):671-678.
The influence of obstetric factors vs. maternal blood glucose control on neonatal morbidity was examined in 261 women with GD (plus a control group of 218 women without GD). Although the GD group had more morbidity (23%) than the control group (13%), it was found to be mostly due to gestational age at delivery. After correction for this factor, pre-pregnancy maternal weight was the only factor with added significance. "The present study clearly illustrates that other factors besides blood glucose control are of importance for neonatal outcome in gestational diabetic pregnancy."
*Numerous further gestational diabetes references can be found in the websection on GD and GD testing on this website. They are far too extensive to be duplicated here! To check out some of these references, click here.
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