November 19, 2008

Myth Busters: Gestational Diabetes is Indeed Real Diabetes

If you have had Gestational Diabetes you may be confused about whether this means you have "real diabetes." If your family doctor is like most you may have been told not to worry about it. Many doctors treat GD if it were nothing more than a complication of pregnancy which goes away when the pregnancy is over.

So while today's obstetricians are aggressive about helping their patients control their blood sugars through the pregnancy, as soon as the baby is delivered, they hand women with GD back to their primary care doctors whose attitude towards blood sugar control is far more relaxed, giving the woman with GD the message that their diabetes is "over."

Post-pregnancy screening, if it occurs at all may be nothing more than administering a single A1c test or, perhaps, a fasting glucose test. If these come back "Normal"--i.e. under 7% for the A1c and under 125 mg/dl (7.0 mmol/L) for the fasting glucose--the doctor will consider the case closed.

Unfortunately, it isn't closed, and the fact that you developed GD should be treated as a big red flashing warning. A new study published in the Journal of Clinical Endocrinology and Metabolism looked at the genetic make up of a group of women who had had Gestational Diabetes and compared it with a group of women who did not. They concluded "The prevalence in a prior GDM [gestational diabetes mellitus] group of several previously proven type 2 diabetes risk alleles equals the findings from association studies on type 2 diabetes. This supports the hypothesis that GDM and type 2 diabetes are two of the same entity." [emphasis mine]

This study found that the group of women who had experienced GD had a frequency of 11 different genes linked to diabetes that was very similar to that found in groups of people who have been diagnosed with Type 2 diabetes.

Common type 2 diabetes risk gene variants associate with gestational diabetes.
Jeannet Lauenborg et al. Journal of Clinical Endocrinology & Metabolism, doi:10.1210/jc.2008-1336

The only reason that your PCP doesn't think you have diabetes, is that he is using much laxer standards to diagnose than your gynecologist did.

We know that women tend to develop diabetes in a pattern where the post-meal control deteriorates many years before fasting control goes away. This is probably one reason why obstetricians screen for GD with the glucose tolerance test, NOT the fasting glucose test. But most PCPs still screen women for diabetes using only the fasting glucose test. Those who don't often rely on A1c test, a test which even the ultra-conservative ADA says should not be used for diagnosing diabetes.

Your blood sugars may be going into the diabetic range after meals but if your fasting blood sugar is only in the "impaired" range, your A1c may be somewhere between 5.9% and 6.3%. That is a value too many PCPs consider to be normal, though, in fact, it is linked by a lot of research with a much higher risk of heart disease. And even worse, blood sugars that go high after each meal make you more insulin resistant and more insulin resistance causes even higher blood sugars. They also may poison the rest of your remaining beta cells, via what is known as "glucose toxicity."

If you are a woman in the early stages of diabetes, the only test that can accurately tell you if you are diabetic is one that looks at your blood sugars after you eat a high carb meal or drink a glucose solution. The Glucose Tolerance Test is a good test. Or you can test yourself at home using the meal test described on this page: Am I Diabetic.

If you see a result over 200 mg/dl (11.1 mmol/L) after a meal two or three times make sure you have washed your hands before testing so you aren't getting sugar from your fingers on the test strip. If the reading is real, you should assume you have diabetes and get back to controlling your blood sugar the way you did when you were pregnant. The ADA's published criteria for diagnosing diabetes include two random glucose tests over 200 mg/dl (11.1 mmol/L) though many family doctors are ignorant of this fact.

Obstetricians train their patients to shoot for much lower blood sugars than do PCPs and most endocrinologists. This is because they have learned that normal blood sugars results in normal pregnancies. Unfortunately, family doctors have not gotten the message that diabetic complications can be prevented by maintaining normal blood sugars no matter what the diagnosis, so they are much less aggressive in helping people get their blood sugar back to the normal range.

Another major issue that many doctors ignore is the question of when, during your pregnancy, you developed gestational diabetes. Typically this happens towards the end of the pregnancy as women get larger and more insulin resistant.

But some of us, like, say, me, became diabetic much earlier in our pregnancy, and when this happens it may point to something different from insulin resistance being at fault. Early GD may be caused by insulin deficiency.

If you have a condition that causes beta cell dysfunction, as opposed to insulin resistance, pregnancy may unmask it. These conditions occur in in young, thin people who doctors don't think of as being at risk for diabetes, so doctors often don't notice these forms of diabetes until they have had years to ravage your body and finally cause serious symptoms. Despite my having had two diabetic pregnancies where I became diabetic very early in the pregnancy, it was more than a decade until my doctors finally thought of giving me a diabetes test that wasn't a fasting plasma glucose test.

Two forms of non-Type 2 diabetes which can cause Gestational Diabetes that arises early in the pregnancy are LADA, which is a slow-onset form of autoimmune diabetes which seems to becoming much more common over the past decade, and MODY, which is the term used to refer to a group of unrelated genetic forms of diabetes which have in common only that they are passed in dominant genes and that they limit the body's ability to control blood sugar.

You can read about LADA here: and about MODY here:

MODY is much rarer than LADA, so if you have had GD when you were thin especially if it came on early in the pregnancy, and if you also have a family history of other autoimmune diseases, that would be the first diagnoses to have checked out.

In any case, the important thing is not what caused your gestational diabetes, so much as making sure that after you have your baby and your blood sugar seems to improve you do what it takes to keep it under control.

With that in mind, here is what I suggest you do. It is what I wish I had done after my GD pregnancies:

1. Every three months test your blood sugar after eating a high carb meal to see how your blood sugar is doing. If you see blood sugars that are over 140 mg/dl two hours after eating, test more often and work on getting your blood sugar down.

You should also put some effort into finding a doctor who will work with you to prevent your pre-diabetes from turning back into full-fledged diabetes.

There are a lot more things you can do at this "pre-diabetic" stage than there are once you've let high blood sugars kill off your beta cells. If your doctor does not take pre-diabetes seriously, find a younger, better trained doctor who will.

2. Go Easy on the Carbs!. Cut down as much as possible on the carbohydrates you eat. Don't drink high carbohydrate fruit juices, spritzers, or sodas, or eat side portions of starchy foods that will raise your blood sugar. You don't have to be obsessional about it, but before you eat something with carbs in it, stop and think: Is this carb really necessary? Some are. But most are not worth the spike they will cause in your blood sugar.

3. Start walking more and sitting less. If you are insulin resistant, exercise may help lower your insulin resistance. Walking is a lot less likely to cause injuries that put you out of commission for long periods of time than are trendier but more injury-provoking athletic pursuits. I learned this the VERY hard way, as I was too aggressive with exercise in my younger years and ended up with serious non-reparable orthopedic problems that now limit my ability to exercise. More walking and less weights and hours on the stair climber and rowing machine would have been smarter!


Pubsgal said...

Great article! Shortly after I was diagnosed (June of this year, 4 years after my second pregnancy with GD), I saw a figure cited on the FAQ for that blew me away. Was it true? I researched it and found the following quote in the document "Type 2 Diabetes Risk After Gestational Diabetes," produced by the National Diabetes Education Program:

"After pregnancy, 5 to 10 percent of women who had GDM are found to have type 2
diabetes. Women who have had GDM have a 20 to 50 percent chance of developing diabetes in
the next 5 to 10 years following pregnancy.(1, 2)"

1. National Institute of Diabetes and Digestive and Kidney Diseases: National diabetes statistics fact sheet: general information and national estimates on diabetes in the United States, 2005. Bethesda, MD: U.S. Department of Health and Human Services, National Institutes of Health, 2005.
2. American Diabetes Association: Gestational diabetes mellitus (Position statement). Diabetes Care 2004; 27(Suppl. 1): S88-S90.

I wish I'd had your advice seven years ago. Although I was pretty much doomed to develop diabetes--family history plus two pregnancies with GD--it would have been better to have saved my pancreas the abuse.

Anna said...

Super post! It's amazing how often women tell me they, too, had gestational diabetes, while they chomp on that bagel and frappeccino.

Just as you describe, GD is downplayed or forgotten after the pregnancy and many years go by while high BG goes on undetected. It's the same story for me and many other women.

Brenda Bell said...

In a previous issue of Clinical Endocrinology and Metabolism, it was noted that one of the big issues with GDM is that new mothers are lost to follow-up; another is that there are three conflicting standards for who should follow up, when, and how.

Until we understand the importance of coordination of care and postpartum follow-up, women will remain undiagnosed and untreated.

That said, perhaps the correct standard of care should be to consider a diagnosis of GDM to be identical to a diagnosis of Type 2 diabetes, with postpartum therapy adjusted similarly to that of other Type 2 patients.

Jenny said...

I suspect that the actual long term incidence of diabetes in women who had GM is higher than 50% but the problem as Brenda points out is that the patients are "lost to follow up."

However, I don't think we should assume GD means Type 2, because I know quite a few people besides myself who have various forms of "Type 1.5"--insulin sensitive diabetes, some autoimmune, some not.

Unknown said...

This so happened to me too! I developed diabetes during my second pregnancy and had to inject insulin. After I had the baby, they claimed that I was now just fine. I so wish I had insisted on fasting glucose tests however I had no idea that diabetes was in the future for me. Years later, I was diagnosed by sheer luck. I feel that I could have been diagnosed much sooner had I been closely monitored after my pregnancies.

Jenny said...


The fasting glucose test is the test that DOESN'T catch most women's diabetes until it is far advanced.

It usually takes a post-meal test or a glucose tolerance test to identify diabetes early.

Mel said...

I belong to a forum primarily of women, most of childbearing age. I've posted this article there, as there have been several in the past couple of years who've been diagnosed with GD. I hope they will read it and take it to heart. I find GD is really downplayed in significance once the baby is born.

Anonymous said...

thanks for great information.....similiar symptoms like type 2 diabetes....and reversible

Anonymous said...

Jenny, thanks for the great information. I had two GD pregnancies and don't want to progress back to full-blown diabetes. I'm one of the women who've had a "good" fasting glucose numbers and have been waved on. Do you have info on your site about pre-diabetes and how to prevent it from becoming worse?


Jenny said...

The way to prevent pre-diabetes from getting worse is to follow the same kind of diet that controls blood sugars for someone with full-fledged diabetes.

Cut down on carbohydrates as much as possible. Exercise in moderate ways that don't risk damage to tendons and joints. Brisk walking is safest.

You might get some ideas from this page: A Diabetes Diet is Different from a Weight Loss Diet.

If you diet for weight loss, use a low carb diet.

Anonymous said...

Thanks, Jenny. I'm reading the link you suggested and am curious about this; "Atkins, for example, tells you to start out with 20 grams a day. Protein Power, a healthier low carb diet than Atkins, starts you at 30 grams."

Why do you say PP is healthier than Atkins?


Jenny said...

Protein Power is a healthier diet than Atkins for several reasons.

1. More low carb vegetables

2. Much more information about what foods to eat

3. The science behind the explanations is much better than Atkins. Atkins books are filled with very old, outdated, and often discredited research.

4. Eades actually eats what he recommends, unlike the case with Atkins.

5. Much more detail about how to eat in different situations and better explanation of how to maintain.

Unknown said...

Great information! I was lucky with my two bouts of GD in that I was treated by a world renowned gestational diabetes doctor who advocated VERY tight control of my sugars during the pregnancies. She also informed me that I was at high risk for developing type 2 diabetes later in life, particularly if I allowed myself to be inactive or get overweight. I did neither, and had my fasting and A1c checked yearly. I was recently diagnosed as a type 2 diabetic with an A1c of 7.0% (had been 6.2-6.5% for ~ 10 yrs post pregnancies but climbed to 7% over last 4 yrs). I have been taking metformin ER and although I initially saw a response (A1c down to 6.5% after 3 mnths and 20 lbs weight loss), I was also low-carbing so hard to know which had the most beneficial effect. Now I'm beginning to think I'm likely a type 1.5 since I believe my father was considered a "borderline" diabetic and may have taken insulin during his early 20's but then stopped for unknown reasons. Not clear to me whether I'm a LADA or MODY type 1.5 though...any thoughts?

Jenny said...

If your dad had LADA he would have ended up back on insulin because LADA invariably progresses to full fledged Type 1--usually over 4 years or so.

MODY doesn't usually progress like that so a person with a mild MODY might end up with ugly blood sugars that could do damage as they aged, most commonly a heart attack, but they could ignore them and wouldn't end up in the hospital with DKA the way someone with LADA would who ignored their blood sugar.

But there probably are quite a few other genetic syndromes functionally like MODY but not involving the same genes.

The vital thing is, whatever the cause, keep your blood sugar normal, and for either type of diabetes I personally think Insulin is the best solution. The sulfs will work for some MODYs, but they will really pack on the weight.