October 5, 2011

Normal Blood Sugars in Pregnancy

I have until now avoided discussing the issue of what normal blood sugars should be in pregnancy because it looked like gynecologists were being more aggressive with blood sugar control during pregnancy then other doctors.

Blood sugar control is particularly important in pregnancy because a fetus that is exposed to continually high blood sugars will experience significant changes in the way that its genes express which will affect its blood sugar metabolism for the rest of its life.

High blood sugar will also make babies very large, which poses problems when it is time for delivery, some life-threatening.

Blood sugars are lower in pregnant women because there is a higher blood volume during pregnancy, but it is starting to look like the targets gynecologists have been recommending, which would have been excellent for non-diabetic women are considerably higher than normal.

This was made clear by a new meta-study that analyzed a series of studies of the blood sugars of a wide range of normal pregnant women using Continuous Glucose Monitoring, home testing, and hospital lab results. It makes it clear that the current targets for pregnancy are probably too high.

Here is the full text version of the meta-study:

Patterns of Glycemia in Normal Pregnancy: Should the current therapeutic targets be challenged? Teri L. Hernandez, et al. Diabetes Care July 2011 vol. 34 no. 7 1660-1668.

It concludes that the following appear to be truly normal blood sugars for pregnant women:


Fasting: 70.9 ± 7.8 mg/dl (3.94 mmol/L ± .43)
One Hour Post Meal: 108.9 ± 12.9 mg/dl (6.05 ± .72 mmol/L)
Two Hours Post Meal: 99.3 ±10.2 mg/dl (5.52 ± .57 mmol/L )

A commentary published in this month's Diabetes Care gives more insight into the importance of this study and why doctors should aggressively lower blood sugars in pregnancy. You can read it HERE. The Full text version is free.

The commentary suggests that pregnant women should strive for blood sugars that don't exceed the first standard deviation of normal (that's the average with the number following the "±" added to it. Doing that gives us targets that should not exceed

Fasting: 79 mg/dl (4.4 mmol/L)
One Hour After Meals: 122 mg/dl (6.8 mmol/L)
Two Hours After Meals: 110 m/gdl (6.1 mmol/L)

The challenge during pregnancy, of course, is to lower blood sugar without going too low because hypos can also cause problems for the fetus. In addition, the solution that works so well for non-pregnant people--cutting way back on carbs--raises issues.

Very low carb diets raise the concentration of ketones in the blood. This isn't a problem when we aren't pregnant--most of our organs can run quite happily burning ketones. But because ketones are usually produced when humans are starving, it is very possible that fetuses produced when the mother is in a ketogenic state may end up with environmentally-produced permanent changes to their genes (epigenetic changes, to use a technical term) that will predispose them to gaining weight once they are born, because ketones may signal the forming baby that they are being born into an environment of scarcity.

The fact that ketogenic diets downregulate T3 and slow the thyroid in non-pregnant people raises the question about whether a ketogenic diet might also have a negative effect on the baby's developing thyroid.

So it's generally considered to be best for pregnant women to lower their blood sugar as much as possible by cutting back on carbohydrates but to keep their carbs over the threshold (anywhere from 60-100 grams a day) where glycogen is depleted and the concentration of ketones in the blood and urine rises.

You can usually detect your own ketogenic threshold easily: it is the carbohydrate intake level at which, after eating at that level for three days, you suddenly lose anywhere from 3 to 8 lbs (depending on your size.) Raising carbs will immediately restore those quickly lost pounds because they are not fat (or growing baby) but the glycogen stored in your liver and muscles which gets burned away when your carbohydrate level is too low to replenish it.

If you eat only enough carbohydrates to keep your glycogen replenished, you won't have to worry that ketones will give your fetus the message that it's being born into an environment where starvation is occurring and shift its genes into a state where they optimize fat storage.

If you can't lower your blood sugar during pregnancy with diet alone, insulin is a safe medication for pregnant women and most doctors provide pregnant women with diabetes much better education in how to use insulin than family doctors do to their non-pregnant peers.

If you are reading this because you are pregnant and have just discovered you have gestational diabetes though you were not diabetic before your pregnancy, here's one last important fact to keep in mind: abnormal blood sugars in pregnancy almost always point to the pre-existence of abnormal sugars in the non-pregnant state that were missed by your doctor because the tests doctors use to screen for diabetes do a woefully bad job of diagnosing it until you have suffered years of high blood sugars that may irreversibly damage your organs.

Once you deliver your baby, don't rely on doctors to tell you if your blood sugar is normal. Test your blood sugar after meals every so often with a meter to make sure that you are not going over the 140 mg/dl (7.7 mmol/L) level at one hour that is truly normal in the non-pregnant state and that you are under 120 mg/dl (ideally far under) at two hours. If you are going over these levels, cut back on your carbohydrates and if that doesn't help, find a doctor willing to work with you to use safe drugs like metformin that can keep your sugars in the normal range for life.

Don't rely on the A1c test, as most doctors now do. It has been shown to be a poor guide to the high post-meal sugars that characterize the very early stages of Type 2 diabetes and which cause heart disease and early diabetic complications.


aschka said...

"abnormal blood sugars in pregnancy almost always point to the pre-existence of abnormal sugars in the non-pregnant state that were missed by your doctor"

I have suspected this for a while, but have read it first here. Where does this information come from?

I had gestational diabetes and had my baby 4 months ago. Post-pregnancy, my 2 hour post-prandial readings are normal, but my 1 hour pp is consistently over 200. Nobody wants to believe I am still diabetic and all I hear is, "Stop worrying about it. Eat whole grains, fruits and vegetables blabla."

Jenny said...


Repeated readings over 200 mg/dl at any time are diagnostic of diabetes according to the highly conservative American Diabetes Association in it official document, Criteria for the Diagnosis of Diabetes Mellitus.

If you can't change doctors you must escalate this with whoever runs the practice asking why they are ignoring the ADA's diagnostic criteria.

Have you tried cutting back on your carbs and are still getting those kinds of numbers or can your 1 hour sugars be controlled with diet?

aschka said...

I'm in Europe so perhaps that is why I am stumbling on this "2 hour reading only" criteria.

I've been behaving like a newly diagnosed diabetic for the past few months, poring over everything I can find about low carb diets, and getting pretty good control of the 1 hour sugars so far (>140). Lately I've been wondering if I should go lower (1 hour >120, 2 hours > 100).

I just got blood test results which the doctor says are "normal": HbA1C 5.4%, fasting 63, insulin 1.8. However I had already been cutting carbs by then for 2 months.

Jenny said...

Lower is better, BUT, lowering sugars in a way that starts to feel like self-denial can backfire. For a while you'll be enthusiastic, but blood sugar control has to be for life, and if you are too stringent, you may end up burning out a couple years down the line and when that happens it is very easy to lose control.

So I tend to think that the best approach is the one that is more moderate and which you can, realistically sustain for years to come. Your numbers would make me happy. But not everyone agrees with me on this and some people would urge you to go for the best numbers you can get.

aschka said...

Thanks Jenny, and thank you for all the info.

epeidi said...

"Blood sugar control is particularly important in pregnancy because a fetus that is exposed to continually high blood sugars will experience significant changes in the way that its genes express which will affect its blood sugar metabolism for the rest of its life."

I was born from a mother with gestational diabetes. I got so big and came so fast that my mothers body went into shock during delivery. Now I am a thin 28 year old female (5'6 120 lbs). In recent years I have had excessive yeast infections, a UTI, get dizzy, get blurred vision, etc. Am I still at a greater risk for developing diabetes, even though I have never been overweight as a result of my mothers gestational diabetes? What tests would confirm if my gene expression is affecting my blood sugar metabolism?

Jenny said...

The best way to find out if you have abnormal blood sugar is to follow the instructions you'll find HERE.

If you're currently pregnant, use the pregnancy normal values on listed this blog post not the values you'll find on the page.

Dr J said...

I am concerned that your worries about the epigenetic effects of ketosis during gestation may be misplaced. Can you provide the citations for this, please? I have looked at the main site and have not been able to find them. Thanks.

Jenny said...

The main data we have about starvation and its impact on diabetes in offspring is the WWII Dutch Famine study: http://www.ncbi.nlm.nih.gov/pubmed/9449872?dopt=Abstract.

There are no studies of the impact of exposure to maternal ketones on infant health that I know of, because no one would knowingly expose pregnant mothers to a diet whose effect is not known. But there is a great deal of research coming out on impacts of all kinds of maternal chemistry on infants, so one would be well advised to be cautious.

Even the most enthusiastic of the low carb diet doctors do not advise eating at ketogenic levels during pregnancy.

Dr J said...

"Even the most enthusiastic of the low carb diet doctors do not advise eating at ketogenic levels during pregnancy."

You may wish to revise that statement. I count myself as an enthusiastic low-carb diet doctor and I do recommend ketogenic diet during pregnancy. If you would like to know about our personal experience with this, see my blog at www.drjaywortman.com.

There is also a fertility doctor in Florida who has found ketogenic diet to be effective in reversing infertility and who keeps his patients on the diet during pregnancy. You can read Dr William Davis' interview of him here: http://www.trackyourplaque.com/blog/2010/06/low-carb-gynecologist.html

I am aware of the literature on epigenetics but I think we need to be careful in extrapolating from starvation studies to what might happen when a ketogenic diet is followed during gestation. Ketosis would certainly be occurring during starvation but a lot of other things are happening as well. It cannot be assumed that physiological levels of ketones would be the sole epigenetic signal leading to downstream effects. I work with populations whose traditional diets were ketogenic. While they do have a greater risk of obesity and diabetes, this happens only after they have deviated from their traditional diet. Since the dietary changes began far in advance of the obesity and diabetes epidemics, there appears to be a generational effect here that may be explained by epigenetics. It is entirely possible that their exposure to a non-ketogenic diet in utero predisposes to the downstream problems.

Lila said...

I am T1 and 27 weeks pregnant and normally agree with anybody recommending tight control; however in this case I have to say that these targets are neither realistic nor reasonable. It might be workable for GD patients who
are able to manage on diet/exercise. But it's not possible - and could even
be unsafe - for women using exogenous insulin.

The main reason is that quick-acting insulin lasts anything from three to five hours. Therefore, it's insufficient to look at PP+1 and PP+2 because it doesn't give the full picture. I am guesing that in a truly normal pregnant woman, BG is back to baseline by PP+2, so PP+3, PP+4 and PP+5 would be the same as PP+2.

After 27 weeks of testing my blood sugar up to 20 times a day, I soon
realized that if I was under 7.8 at PP+1, I was guaranteed a hypo at PP+2 and then another hypo at PP+3.

If my PP+1 is in the 4s and 5s, that means a hypo is on the way at PP+1.5, and another at PP+2. A PP+1 reading in the 4s and 5s with no ready sources of quick-acting carbohydrate means hello paramedics.

The only times I had no hypos at PP+4 and PP+5 (back to 4s and 5s) was when PP+1 was 10-12, and PP+2 was 7-8.

So the only way I have been able to hit the 7.8 PP+1 target (which this
article is arguing is too high) has been to watch my blood sugar like a
hawk for up to five hours after eating and catch hypos before they hit. This is only possible on the days when I work from home.

Unfortunately exogenous insulin is imperfect. So which 'normal' blood sugar is better, and when? 'Normal' PP+1 and PP+2 leads to abnormally low PP+3/4/5 - and some of these can be so low that they can be
life-threatening, which is not good for either mum or baby. If PP+3/4/5 is 'normal', then PP+1 is abnormally high and PP+2 is high - but there is little chance of hypos.

I am now entering a stage of my pregnancy where I am having the opposite problem though. Glucose is sticking around for longer, so I can have perfectly normal PP+1 and PP+2 numbers, then get whacked with nasty 9s and 10s at PP+3 and PP+4.

I was eating lowish carb before my pregnancy (50-100g) but am now eating 100-150 most days. As you rightfully point out, the ketone issue means low carb isn't a totally feasible option. So basically, you're damned if you do, and you're damned if you don't.

Don't get me wrong; in general I always think tight control is good. I have an A1C of 4.9 on the 7.8 targets; that has involved daily hypos and one near-death episode from low blood sugar. I don't begrudge any of the hard
work but I also have to balance risks. And based on my own personal experiences thus far, I have to say I am more afraid of the risks posed by trying to reach the blood sugar targets proposed in this article.

Jenny said...

Dr. J,

The problem I see with your argument is that it is all speculative. We just don't know. And there is the further problem that people become religious fanatics when diet issues are concerned.

I wish someone would do a study why explains why dietary issues call out the same kind of fanaticism as fundamentalisms. But after 13 years of participating in online diet discussions I am convinced there probably is a brain function issue involved.

But what I've observed is that people go through conversion experiences, followed by evangelism, followed, all too often 3 to 5 years later by backsliding, until they find some new "religion" to adhere to.

When the issue is weight, this is merely a curiosity. When it is diabetes, it can prove tragic. That is why I consider extreme diets no matter how useful in the short term to be dangerous to people with Diabetes. Because they have to eat in a way that controls for life.

The very few indigenous people who adapted to ketogenic diets (and they are very few) would have selected for them in the harsh conditions they live in, so it's possible that is a better diet for them. But that isn't the case with most other lineages.

The fact that long term low carbing does cause problems with T3 for a lot of people is another reason I would not be enthusiastic about a ketogenic diet in pregnancy.

This is something that is observed anecdotally throughout the long-term low carb community, but the religious fanaticism of that community's medical leaders keeps it from being discussed. Those of you who have eaten Keto for 3+ years (as I did) and ended up barely able to lift your legs will know why I consider this a big issue.

My poll a while back of long term low carbers 3+ years who had maintained weight loss found that almost all of them reported doing much better at 100 g a day than below 60. Some of these people had been at it for over a decade.

Jenny said...


You explained brilliantly the problem that arises if we have to achieve control with injected insulin. My own experience confirms that insulin potency varies from vial to vial and even the same vial will have different potencies over the course of the month.

There are also huge differences between the different analogs. I would ask if you had tried a different one. I had the experience you describe with Humalog, but Apidra worked in a physiological manner to me and because it has a shorter time of activity, it would be gone at 2 hours and not cause those 3 hour lows. Novolog I found to fall between Humalog and Apidra in terms of how long it acted.

This is very much a personal thing. There are people who do better with Humalog. And from my experience, doctors who have never used insulin themselves, have no idea that the different versions are different--or that the curves published in the prescribing information are averages that don't represent ANYONE's actual experience with them.

I know it can be a problem getting insurers to pay for Apidra, but it might be worth paying for a few pens yourself to see if it makes it easier to get control. You can shoot at meal time and correct later knowing you aren't going to plummet as it is done working.

Dr J said...

In my household, we have been eating very low-carb for nine years. We have not encountered any problems and certainly have seen no sign of T3 (BTW this is the first time I have heard that this is a problem associated with LCHF). My eleven year old son eats some carbs but no sugar. My two year old daughter has no taste for carbs which I think is because she is the product of a very low carb gestation. She is growing like a weed and is very precocious in every way.

My work is focussed on researching LCHF diets so I follow the literature and am involved in a number of studies. One area of interest is the history of diet and, here, I have to disagree with you. Prior to the advent of agriculture the amount of carbohydrate consumed by our forebears was quite low in many places. As to the indigenous populations who ate a low-carb diet in more recent times, they covered a large area of northern and western North America. The plains Indians, for instance, lived on buffalo. Pemmican, their staple food, was 80% fat and 20% protein. They added berries only after the white fur traders started using it for portable rations. When first observed by Europeans, it was noted that their height ranged from 6' to 7' tall. Height is an indicator of general health status and good nutrition.

The west coast First Nations rendered the fat from oolichan fish and got about half their calories from this one marine oil. Their only carbohydrates came from berries and some seasonal greens in the summer. The Inuit diet of mainly fat is also well known. I could go on but the point is that a low-carb diet was widely practiced. If it was harmful to infants, how could this have occurred? It defies logic.

As to speculation, I would agree that since there are no trials it is not possible to conclude that low-carb gestation is harmless. But, that goes both ways. You can't conclude it is harmful either. Based on my knowledge of the history of diet and my own experience of benefit over a nine year period plus my understanding of the physiology of carbohydrate and ketone metabolism, I see no reason not to continue a ketogenic diet during gestation. Based on my n=1 experience, I am certainly happy with the result.

Jenny said...

Dr. J,

The problem with T3 is one Dr. Eades had written about on his web site back in the late 90s where explained that he had had to treat some of his long term patients with T3. When asked about this some years later, he denied it, but I found the page from his site where he'd written about supplementing T3 on the Wayback Machine Web archive. It was true.

Dr. Bernstein remarks that many of his VLC diabetes patients end up needing thyroid supplementation. He attributes this to their developing a second autoimmune condition. However, I and others I've heard from who don't have any autoimmune conditions have also experienced this problem.

Not everyone gets it. And if you don't, you're fortunate. Do you have diabetes?

Jenny said...

I'm going to resist the temptation to debate Paleo here, as that isn't what my blog readers come here to discuss.

But my first degree (from the U of Chicago) was in in anthropology and archeology so I and have read a lot more primary source material about pre-agricultural life styles than most. I feel very strongly that Paleo enthusiasts cherry pick from a very small amount of often questionable accounts to support their views.

My reading has taught me that many North American hunter-only societies often lived on the edge of famine at most times, with severe famines periodically decimating the population. This is well documented by accounts from the 1500s through the late 19th century. If those who survived these harsh conditions were very healthy it might have had less to do with their diet than the fate of their less robust non-surviving siblings.

But these hunting groups were were very small populations usually impacted by special geographies. The bulk of pre-Columbian Americans were agricultural (going back milenial in the Amazon basin, which archeologists are only now coming to realize.)

There's a reason why populations explode when agriculture provides a steady food supply and why most humans turned to agriculture if they lived in environments that would support it. While individuals might not have been as "healthy" their children--including those whose strengths were intellectual rather than physical--were far more likely to survive to reproductive age.

But like I said, this is a diabetes blog so I'm going to ask people to stick to discussions of diabetes in pregnancy here.

Dr J said...

When you said T3, I thought you meant Type 3. Although we have had no problems with thyroid, I believe there is evidence that reducing carbs does result in lower thyroid output. There is a physiological explanation for that. A normal blood sugar represents about a teaspoon of glucose in the circulation. The body wants to keep that in a very tight range. When you eat a carb heavy meal, you create a "metabolic emergency" with the sudden influx of glucose. Your body responds by secreting insulin to push the glucose into the cells to be burned for energy, to convert excess glucose to fat in the liver and to push the fat into the fat cells where it is out of the way and won't interfere with the burning off of the glucose. In that scenario, increased T3 is useful in terms of increasing the rate at which the glucose is burned. Doing this on a chronic basis, in susceptible people, leads to burn out of the beta cells. I think that the thyroid burns out for the same reason. If you stop eating carbs, the thyroid responds by lowering T3 production. For some people, whose thyroid capacity has been damaged, T3 will go too low when the stimulus of high carbs is removed. It doesn't happen to everyone and it's not an indication that carbs are needed. It's just another indication that high-carb diets are not healthy.

I respect your request that this not devolve into a debate on paleo, however, I would direct your attention to a relevant article by Jared Diamond:


Yes, I am a type 2 diabetic. I have been well controlled without meds for nine years by eating LCHF.

Jenny said...

I'd be the last person to argue for high carb diets.

But one other thing I learned reading the newsgroups for many years was that surprising numbers of people with Type 2 could achieve normal blood sugar levels by cutting carbs back to nonketogenic levels using the strategy first pioneered on alt.support.diabetes which you'll find HERE.

In fact, it was observing that which first made me question if I was Type 2 (I'm not, it turns out) since even when eating Bernstein's diet (which I did for several years) I couldn't get my blood sugar to a truly normal level. I turned out to need supplemental insulin.

Dr J said...

I had a look at the link and I agree it is a sensible approach to getting blood sugar under control. The one concern I would have, though, is that raising carb intake to the threshold where blood sugar starts to rise may be problematic in the long run. Blood sugar may be normal but at the cost of continuing pancreatic beta cell burn out. Once somebody has been diagnosed with T2, they have lost about half their beta cell capacity. The approach they take from that point on should be to maximally preserve beta cells by not taxing them with the need to produce any more insulin than absolutely necessary. That means minimal carbs (I don't include non-starchy vegetables in that, btw). Beta cell preservation is also the rationale for introducing insulin early in the conventional management of T2.

Jenny said...

I have not seen any research that convinces me that beta cells "burn out" just by secreting insulin. Instead, what seems to happen is that beta cells in people with Type 2 succumb to glucotoxicity because people with Type 2 are encouraged to maintain blood sugar levels that spend hours a day in the high 100s which is the range where glucotoxicity kicks in.

When blood sugar levels are under 160 or so, though, people with insulin resistance just grow more beta cells. This is demonstrated in a very elegant study you can read HERE.

Long term analysis of UKPDS didn't show any difference in progression between those on Metformin and those on insulin stimulating drugs, which also seems to me to dispose of the "secreting too much insulin burns out beta cells" argument.

Running blood sugars that spend hours over 140 kills beta cells. That's been demonstrated.

semsons.group said...


a very dumb question, when you say 60-100 gr of carbohydrates, do you mean the weight displayed by balance of the onion+peppers+lettuce+etc must not be over 100gr, or do you mean the amount of carbohydrates that goes to the blood stream. If it's the last case, in what measurable weight would roughly translate for vegetables+fruit?.


Jenny said...


The grams of carbs refers to the carbs listed on the nutritional label (or in a nutritional database like this one) which would be the amount of the food that turns into carbohydrate in your body.

To be accurate you will need to know the weight (or volume of your food) since the nutritional values are always given for a set portion size. I have found a food scale very helpful in figuring this out. The one I use can be found on Amazon HERE.

Harold said...

It is important to realize that the amount of carbohydrate is not an exact amount. The USDA allow the amount on the label to be within plus or minus 20%. So if it says 100 grams it could be anyplace between 80 g and 120 g. That's a big difference if you are taking insulin. Who measures any one package? Maybe a batch and who knows how often and probably only a calculation so there is lots of room for error. The only way you can know is to measure what it does to your blood glucose.

Jenny said...


You make a good point. There is variation in foods--but I haven't seen a 20% fluctuation in most packaged products, based on my meter response.

Where things get dicey are pieces of fruit--or restaurant foods and baked goods where the ingredients aren't standardized.

Still, knowing that a 43 gram piece of bread is about 20 grams is very helpful, and if you weigh things you won't eat a 6 ounce 90 gram muffin thinking it's the 2 ounce muffin 30 gram muffin you see listed in the nutritional database.

Harold said...

I agree with you if you stay away from all packaged foods you don't have to worry about any labels but if you read Bernsteins form and others it seems that a lot of readers have a biblical attitude towards them that is that they are exact and they need to understand that they are not exact but an estimation at best.

jimpurdy1943@yahoo.com said...

Jenny, I'm sorry that this question is off topic, but I'm not sure where else to ask it.

Anyway, I've noticed something today was very surprising to me. I refuse to take medications of any kind, and I really struggle to get blood sugar out of the stratosphere. But today, I did something that probably is supposed to be a big no-no for a diabetic: I binged on a fast food delivery of 30 (yeah, 30) chicken wings, deep-fried in peanut oil.

To my amazement, my blood sugar readings plummeted rapidly after eating the chicken wings, just as if I had taken a big dose of insulin.

Does that make any sense? I'm thinking about buying a bunch of plain (no additives) Wal-Mart chicken wings and cooking them in my microwave, plain, without any oil or seasonings.

Any comments?

Jenny said...

Chicken wings without a floury coating should have no impact on your blood sugar at all, but the fast food ones are usually full of flour. So that result doesn't make much sense. Did you repeat your meter readings to make sure it wasn't a bad strip?

That said, if you are struggling to control your blood sugar you may need insulin which isn't a drug but a replacement hormone. The R insulin (sold as a generic at Walmart) is the identical molecule to what your body produces. I'd suggest reading the book, Dr. Bernstein's Diabetes Solution, to learn how to use it, and then talking it over with your doctor to get the necessary prescriptions. R is available without prescription most places but you will need needles which usually require them.

jimpurdy1943@yahoo.com said...

Jenny, I apologize again for continuing this off-topic intrusion, but it's getting interesting to me. I have also been asking Seth Roberts (also off-topic on his blog) about my binges ... I mean self-experiments here, with more details about my 200-point drop in blood sugars. My doctors would be shocked, but I'm going to repeat this experiment to check the results. Oh, and the chicken wings were plain, with no breading or anything else, except for being deep-fried in peanut oil. And, yeah, I know that this goes against all medical advice, but a 200-point drop im blood sugar is amazing to me.

Jenny said...

Jim, If you can survive a 200 point drop in your blood sugar it is WAY too high, and you need to give up looking for magical solutions like this one and get the help you need--before you irreversibly damage your organs.

Eating a no carb diet might control your blood sugars but very few people can stay on such a diet and it is extremely hard to craft one that is nutritionally sound. Even Dr. Bernstein tells people that they need to use safe drugs and insulin when a diet of 30 grams a day of carbs won't control their sugars.

Andreboco said...

Jenny, I love your blog and I am also a fan of Dr. Js. You are both on the same side fighting the same fight. It was a great back and forth. Obviously Dr. J is a reader of yours. Please check out his web and the movie they shot of his work with 2 Indigenous Tribes in Canada. I am forwarding these comment threads to Dr. Bernstein and Dr. Ron Rosedale. They should enjoy them. Lastly Jenny, do you have any desire to present or attend the Ancestral Health Symposium in 2012? You are quite often mentioned in the Paleo blogosphere with regards to your brilliant work and breakdowns. With your anthro background, it would be fun to see you there.

Jenny said...


So far I have never been invited to ANY of the get-togethers that other diabetes bloggers rave about. I've assumed this is because they are usually sponsored by companies selling products who aren't fond of my outspokenness. I know for a fact that numerous people have suggested I be invited to one of the biggest, but the company involved, who sell innaccurate blood sugar meters, have not invited me.

I'd be very interested in attending the paleo get together, but as many of you know I have strong feelings about the way that Paleo believers often turns it into a romantic reinvention of the past that ignores a century of scholarship.

As an anthropologist what most fascinates me is the way in which ALL ways of eating take on religious overtones and spark cult behaviors in those who adopt them. This doesn't benefit any of us whose concern is the restoration of health!

Denise said...

"As an anthropologist what most fascinates me is the way in which ALL ways of eating take on religious overtones and spark cult behaviors in those who adopt them. This doesn't benefit any of us whose concern is the restoration of health!"

And THAT would get my vote for a topic for your next book!

Anand Srivastava said...

Hi Jenny,

I am not a diabetic, merely likely to have it based on genes.

I have been researching diet via blogs. I haven't read much yours except occasional articles posted on other sites.

I have become a fan of Perfect Health Diet. Paul recommends at least 50gms of carbs. Based on that I had formed an opinion that it would be best for even diabetics to try to get to that level, as long as BS can be maintained.

I am pleased to know that your recommendation of 60-100, is perfectly matched with Paul.

I would think that Ancestral Health Symposium will be the best matched for you. They cover the whole landscape from very low, to low to high carbs.

Thanks for the resource that you provide everybody.

Jenny said...


You'll make better health decisions if you understand WHY doctors (and others) recommend various strategies and do some research on your own to find out if their arguments hold than if you just eat a certain way because some authority recommends it.

What was Dr. Paul's rationale for recommending 50 grams? In my experience carb level isn't a one size fits all thing at all. Some people do very well at lower intakes, other don't. You should always be cautious about books (and doctors) who tell you everyone should eat a certain way.

Anand Srivastava said...

Jenny, Paul is an astrophysicist and an entrepreneur. He is not an MD. He gives reasons for why it should be 50gms, which are formed from his own experiences. But yes that is just a starting point.

For many (most) people this will not be the right number. But it might be a good average. He himself is not a diabetic, so it might not really be a good number. Even if it was it could still not be a very good number.

I just liked that you also think that staying very low carb is not desirable for everybody. I agree it is an individual response. I was just thinking that a lot of people may find it better to reach that number.

I myself am not a diabetic, only prone to be. I follow the paleo/PHD/WAPF principles, with a moderately high carb mostly vegetarian diet.

Jenny said...


The strategy you'll find HERE takes the guesswork out of the question of how many carbs will work for you, personally. It will show you how high a given meal (with a known number of grams of carbs, ideally) raises your blood sugar. Once you know that, you don't have to rely on anyone's theories.

Harold said...

I think 80 gms is about what is recommended in Life Without Bread book.

Joyce said...

Hi Jenny,

I've been scouring the internet trying to find information about high ketones with NORMAL blood sugars in pregnancy, and I'm not finding very much.

I'm almost 28 weeks and my blood sugars are usually between 90 and 100, but my ketones are constantly high, even though I'm eating a calorie rich diet, including a reasonable number of carbs (fruits and veggies mostly). In fact, the only time I was able to get them down to trace was after eating three oranges and drinking 3 glasses of water within a couple of hours. I'm pretty sure this is not a sustainable diet. As soon as stop eating suar, I'm back in moderate ketosis within hours.

Anyway, my endo wants to put me on insulin. He mentioned stillbirth and respiratory issues as complications of having high ketones. I mentioned that I was having a hard time finding conclusive evidence that ketones were bad for the fetus and asked him if he had proof, and he blew up at me, yelling about how he was a board certified endocrinologist, I had to take his word for it, etc, etc. I was somewhat alarmed by this reaction (I hope understandably).

So I'm very confused right now. Is this a reasonable course of action? Is it dangerous to be going on insulin when your blood sugars are already normal? Are there any sources or research I have overlooked in determining whether high ketones levels are actually dangerous?

Thanks in advance for any insight!

Jenny said...

Ketones in the presence of normal blood sugars is a completely different condition from diabetic ketoacidosis which is what your endo is trying to treat.

If those 90s ans 100s are post meal numbers, YES it would be very dangerous to use insulin with normal blood sugars as it would cause hypos.

If they are fasting numbers, then you'd want to test post-meal to see how high blood sugar was going. If it was going over 160 mg/dl(which I believe is roughly the pregnancy equivalent of 200 in nonpregnant people) then very cautious use of insulin would be reasonable. But a better solution if there is, in fact, evidence that ketones are dangerous in the presence of NORMAL blood sugars, would be to raise your carb intake a bit more by adding some starches to your diet rather than sugar.

The problem with fruits and fruit juices is that they have a lot of fructose which doesn't raise blood sugar (but does pile up in the liver as fat) try eating potatoes or sweet potatoes or other starchy vegetables or a high quality whole wheat or sour dough bread if you don't have a gluten problem.

Anonymous said...

Jenny, have you looked at The Barker Theory. It's on barkertheory.org. He has conducted studies for a long time. I recently saw a documentary he featured in, about some women in India, poor and underfed during pregnancy, and the incidence of their children ending up as thin T2s is very high. In fact, from what I know India has one of the highest rates of T2, yet not all are obese.

For a doctor to say a ketogenic diet is ok in pregnancy without several long term studies, is not ok in my book. It could be ok if that doctor can demonstrate that the children of those mothers he treats don't have insulin resistance 30 years later plus other chronic diseases. The famine studies are out there.

Jenny said...

Sooz, No one has really investigated how far the the similarities go, metabolically, between ketogenic diets and starvation resulting in ketone formation, but I agree this is a concerning issue, and I would not recommend eating a ketogenic diet in pregnancy.

People who support this always cite the Inuit, but I have been reading primary source material about the Inuit and find that starvation was a continual theme in their life, and that their reproductive success was very poor. There were only 5,000 Inuit in the Canadian arctic in the 1920s after many thousand years of living there. When western diets were introduced their population numbers skyrocketed.

Corrigan said...

I know this post is several months old, but having just found out I have gestational diabetes a few weeks ago, I've been reading everything I find on the internet, and have read this several times. I did want to address something that Joyce mentioned about ketones. I'm new to GD, but I know that it is actually normal for pregnant women to have some ketones in their urine. Not all pregnant women do, but some do, and I'm not just referring to pregnant women with GDM, but sometimes there are low levels of ketones even in totally normal pregnancies. I haven't read why, but I have read several times that it's normal to have a little more than trace for some women.

Also, Lila stated that she thought truly normal pregnant women would be "back to baseline" by two hours PP. If baseline means fasting levels, then the study shows this is *not* true, since the average fasting level in those healthy pregnant women was 28 points lower than the average 2 hour pp level. That's a big difference! I don't know enough about diabetes of any sort to know if it would be normal for a person with Type 1 or Type 2 to be back to fasting levels 2 hours pp, but if it is, then I would guess that perhaps the reason this isn't the case with GDM is because pregnancy causes digestion to be a bit more sluggish, so perhaps it would only make sense that it would take pregnant women longer to achieve that fasting level after eating. If by "baseline" she meant something other than the fasting level, what does that refer to exactly? Is there a standard definition? I'm still learning. :)

I'm so grateful to you for making this information easily available. It's almost nowhere else on the internet, and the internet is actually full of terrible misinformation about what normal glucose levels in pregnancy should be. I've seen it stated several places that pregnant women are *supposed* to have *higher* than normal glucose levels, which obviously is not true. I'm just so grateful to have found this, since the numbers my doctor gave me as targets are actually higher than this. Since I'm a pretty healthy eater anyway, I've rarely gone over the postprandial numbers here (apparently beans, which are great for everyone else, are *terrible* for me - go figure!) but I want to be sure not to ever, now that I know what's truly normal.

I do have one question, though. My fasting numbers range anywhere from 57 to 101, and I have been keeping track of everything I eat and all my exercise for weeks, but I can find no rhyme or reason to it. They're not usually over 95, but the doc wants them under 90. However, it seems dangerous to me to give insulin or medication to lower my BS, when sometimes it's already below 70 when I go to bed and it's rarely over 110 during the day at any time. Do you have any suggestions for *anything* else I can try to keep them low every night? And if not, do you think it's a good idea to work on keeping them lower, when sometimes they're already very, very low? Thanks!

Jenny said...


It's possible your meter isn't very accurate. A variation of 5 mg/dl could be explained by meter error. Make sure that your doctor knows you are seeing those lows before you try insulin. Another option would be levemir rather than lantus if you used insulin which has a shorter span in which it is active, especially if you aren't insulin resistant and use small doses.

Fasting insulin levels, in and of themselves are not harmful. Doctor pay attention to them because in most people if they are high the post-meal numbers are very high since they eat a lot of carbohydrate.

This is something you should be able to discuss with your doctor, and if it isn't possible, perhaps you need to find a doctor you can discuss it with because there are a lot of issues that will come up with an ob/gyn and you want to feel like you are being heard, but also that your doctor is well-informed and can give you good advice.

It's really good the way ob/gyns are watching blood sugars. They are more alert to this than other kinds of doctors.

Rabia said...

Hi Jenny,

I was wondering if you would be so kind as to answer a related question regarding carb intake. I am currently seeing a diabetes educator who recommends the ADA standard of 175 - 185 grams of carbs a day. However, I am completely unable to keep my blood sugars (especially fasting) under control with this level of carb consumption. What works for me is what you recommended in your post above which is just enough carbohydrates to keep out of ketosis. However, the debate I have with my diabetes educator is around the issue of whether this level of consumption is enough. Her contention is that the baby needs her recommended amount of carbohydrates in order to stimulate adequate brain development. My response was that since babies absorb glucose through the bloodstream, if 100 grams of carbs a day are elevating my blood sugar to the level that a normal non GD person would have if she ate a much higher level of daily carbs, the baby must have plenty of glucose to absorb from my bloodstream. Her argument doesn't make too much sense to me because the higher I go with regards to carb consumption, the more likely the baby is to develop macrosomia, isn't that correct?

Her approach seems to be to increase my carb intake to her specified amount and if I can't handle it, to go on insulin, but to to me this seems like a self-defeating exercise.

I was wondering if you could shed any light on this issue based on any research you have done. (In case you don't check the comments on old blog posts any more, I will email you a copy of this comment.)

Jenny said...


There is zero research on the effect of ketogenic diets on pregnancy, and even the doctors who get rich telling everyone that very low carb diets willl cure everything tip toe around the issue of very low carb diets and pregnancy.

The one issue I see is that at ketogenic carb intake levels some people experience a drop in one of the Thyroid hormones, and there is some evidence that starvation causes babies to become more insulin resistant. So I would definitely avoid a ketogenic diet.

However, a diet of over 110 g a day avoids the thyroid changes in nonpregnant people, so perhaps a diet that is slightly above that range along with small doses of insulin would be optimal.

Lots of women use insulin during pregnancy, and it does seem to be helpful. I didn't get insulin for my diabetes when pregnant (idiot doctors in the early '80s) and had the monster-sized babies. Not anything you want to experience and it does seem to predispose the kids to weight gain as they get into their late 20s,

So I would say don't sweat the insulin. It will give you excellent control with a moderate carb intake.

Rabia said...

Hi Jenny,

Thank you so much for your prompt reply! I completely agree about avoiding a ketogenic diet. I'm actually managing alright without insulin on about 110-130 grams of carbs a day and completely out of ketosis. My fasting blood sugar is in the 80s so not at the optimal range but my post meal numbers are close to what you cited as 'normal' in the post. The only concern I have is whether I should actually be eating 175 grams to be on the safe side as my dietitian recommends and going on insulin to balance that out.

Jenny said...


It probably depends somewhat on your body size. Dietitians are woefully clueless about the fact that the amount that 1 g of carb will raise your blood sugar depends entirely on your body size. A person who is 140 lbs will see a 10 mg/dl rise when they take in 2 g of carb (assuming they don't get an insulin release) where someone 280 lbs will see a 5 mg/dl. So the amount you and your baby need has a lot to do with your size. The smaller you and the baby are, the less carbs you need to eat to get the same amount of glucose in your system.

Remember too that you can have ketones in your blood at a level where you aren't seeing ketones in your urine. So you want to be eating at a level considerably higher than the level at which you stop seeing urinary ketones.

Your reasoning makes a lot of sense to me, but because this is an issue no one wants to take a controversial position on, pretty much you will have to make your own decision. You might ask the dietitian if she can point to any evidence where children of mothers eating more than 110 g but less than 175 g had children with issues. Is this evidence based, or is it part of the whole "Your brain stops working if you eat less than 130g of carbs a day" nonsense so beloved by nutritionists.

As someone who has cranked out a lot of books that sold very well--and done it while eating considerably less than 130 g of carbs a day I know that is baloney. But I have run into issues, long term with ketogenic levels, so I would suggest being sure to keep yourself well above the level that would result in blood ketone levels and any change to thyroid.

shmr said...

Hi Jenny, just want to say I really appreciated this post. Some of the "normal" blood sugar charts out there are ridiculous. I've been testing my blood sugar with a family friend's meter (type 1, physician) because I was having hypoglycemic episodes at 24 weeks pregnant, and he was very concerned I had GDM. I haven't had the GTT yet, so I don't have a diagnosis there.

I just had a question about fasting levels, since you mentioned they aren't as important in the comments. My fasting in the morning level is consistently 5.3-5.6 mmol/L, which is a bunch higher than your recommended level in the post. However I haven't gone over 5.9 at any test in the last week, ranging from 45 min to 3 hours after meals. Just wondering how important that fasting number is if the other two are always lower than the normal pregnancy targets.

I am not eating a good diet or watching carb intake at all, although I can't eat much of anything (NVP issues). Even though I'm totally failing to eat every 2 hours, the hypo stuff stopped after a week or so and I read elsewhere that it can just happen as the baby's pancreas kicks in around that time. Not sure how scientific that is.

Jenny said...


Let you ob/gyn know about your concerns. They are usually very good about watching for GDM. If your post meal numbers are normal it shouldn't be a huge concern especially when you are haven't had a OGTT to diagnose. Home meters can give misleading readings.

Vishalinee said...

Hi Jenny
I'm 30 yrs old female, now I am pregnant 33 weeks,
My GTT is fasting 6.6 mgdl
After meal 2hr 7.7 mgdl
Then my scan report is my baby is bit heavy
And my family history is my mother have DM
Is it I high risk DM patient . I'm very confused now pls help me ,
Before pregnant my GTT was normal .

Jenny said...


That looks be higher than you would like, but not alarmingly high. Your doctor should help you get better control. Eating less sugar and starch will help too.

Both my babies were very large as I was diabetic and my doctors gave me no help back in the 1980s. But both babies grew up into healthy, normal sized, intelligent adults. May your baby do the same!

Anni said...

Great post!

I've just been diagnosed with gestational diabetes a few weeks ago (hence found my way here). My OGTT values were:
5.3 mmol/l (95 mg/dl) fasting, 5.7 (103) 1h and 5.1 (92) 2h postprandial.
I'm quite young, of normal weight and although I don't restrict carbohydrates, I'm on a relatively carb-conscious diet (would estimate having around 100-150g per day).

After the diagnosis, I was given a blood sugar meter to follow my values at home. My 1h postprandial values seem fine (normally 5.0-6.5, a couple of times higher after heavy meals but still below 7.8 and a couple of times around 4.3-4.8 after breakfast), but my fasting values are still always above 5 (usually 5.2-5.7) and way above the truly normal value of 4.4 or less.

The fasting target given to me by my maternity clinic is <5.5 mmol/l and since I've only had a few values higher than that, I'm not being monitored anymore, given insulin or any other extra surveillance. However, I know my fasting value is consistently way above what it should and despite my best efforts (improving diet and avoiding high carbohydrate loads, eating less, having night-time snacks etc), I haven't been able to lower it at all. I've had high (though "normal") fasting blood glucose even before the pregnancy ever since it's been tested, so it seems to a be a longer-term issue for me and one hard to tackle.

My sister and father have also had high fasting values (my sister around 5.5-6 mmol/l and my father 6.3-6.7 mmol/l), with normal postprandial readings in OGTT (although my dad is a low-carber, which might affect his fasting readings), and there's diabetes in my father's family. We've considered MODY2 as an alternative, but we won't be able to get tested for it and since it's so rare, I don't know how likely it is. It would be nice to know if I'm still doing something wrong and there's a way to improve my values by being more diligent or if this is just something I most likely can't control. Should I be worried for my baby's sake and for my own health? I would really appreciate some advice.

I've just discovered this website and it's been very helpful and informative. I'm sorry if my comment is too personal, I'm finding it hard to find anyone to consult re: this issue and thought this would be worth a shot. Thanks so much for all the work you put in this blog!

Jenny said...


I do not know enough about gestational diabetes to comment intelligently on your situation, but I would not worry too much about your fasting reading. While it isn't ideal, the damage done by high blood sugars appears to be due mostly or possibly entirely to post-meal numbers. Yours are normal even for pregnancy.

So your doctor is right not to be overly concerned with those isolated fasting readings.

If you have a MODY-2 gene or one similar, there probably isn't a whole lot you can do except be glad that the fasting values you are seeing are just a bit elevated over normal and don't really require any treatment. For that matter, I am not sure there is any treatment that could lower fasting blood sugars safely in your situation.

EPK said...

I'd like to comment on this post because this is a topic that really gets me: I wholeheartedly agree that a fetus' blood glucose environment likely has many implications for a child's health. And, like you point out, no one is willing to truly 'experiment' with pregnant human subjects. It is therefore very frustrating to me that there isn't there more intelligent thought and discussion on the topic.

I was insulin dependent (and on metformin) throughout a pregnancy 19 months ago. This was not true gestational diabetes as I still have blood sugar issues which I will not go into detail about in this post. I did a lot of research on the topic and challenged my diabetes team quite a bit. It was a very frustrating experience, and as I plan for a second pregnancy, I wish I knew more and others did, too.

So, you are saying that blood sugar targets in pregnant women should be much lower (aside from fasting, these are numbers that I did try to strive for), but, there are currently no real strategies for a lot of pregnant women to attain them. Lila did a great job of explaining some of the difficulties with insulin. So, the main strategy of staying LC is not, as you recommend, really an option. I wish we knew more about ketones in pregnancy. Therefore, we only have insulin. It doesn't sound like you are aware of this, so I wanted to chime in, that during a pregnancy, because of the hormones, women become increasingly insulin resistant as the pregnancy progresses. Her insulin requirements usually quadruple pre-pregnancy requirements--many pregnant women are taking approx 100 units+ towards the end. So if you are someone, like me, who agrees with Dr. Bernstein's approach that the less you take, the less room for error--you come to a big problem in pregnancy. Does he comment on the issue of huge insulin dosing in pregnancy? The other aspect which I'm not sure you are aware of in reading an earlier response of yours, is that there are very few insulins that are approved for use in pregnancy. The only option for a longer acting is NPH.

You also mentioned in passing that we shouldn't be that worried about higher fastings during pregnancy--this was my main issue all along (mainly because I was stricter than my diabetes team liked for carb intake). Do you have a reference for this? This is ironically in the context of an (important) post that gives a very low 'true' target for fasting pregnant glucose values.

So, like everything you write I thought this was interesting and informative. I can't help but feel that it was a little along the lines of: you should be stricter, but, sorry--you can't actually be any stricter. What's a pregnant person to do? Pregnant people need you to tell us more of your thoughts and research about these issues! (Please?)

Jenny said...


Dr. Bernstein has not written a word about pregnancy, nor have I heard him discuss it in teleconferences.

I don't begin to have the expertise needed to make recommendations to women in pregnancy and it would be completely inappropriate to make recommendations to strangers over the web even if I did.

My experience with blood sugars and pregnancies are that I went through two diabetic pregnancies where I was given no treatment at all, back in the bad old days of the early 1980s when patients did not have access to blood sugar meters and doctors weren't aggressive with blood sugar control. I had the predictable huge babies, but they were both healthy and have grown up just fine.

I have had friends who delivered babies given generic insulin doses back in the early 80s (without meters, so the doses were set so that they would avoid readings in the 300s and 400s, but that was it. Their kids were fine, too. Hence though I am very glad that obstetricians are much more conscientious nowadays about blood sugar control, I think that people who don't have Type 1 diabetes and are under the care of a reasonably well trained obstetrician don't have to obsess.

The point of all that control is to keep the baby from becoming overly huge or exposed to toxic blood sugar levels.

From what I have read, the problem with being in a ketogenic state while pregnant is that it might cause epigenetic changes in your baby's genes which give it the signal that it is being born into an environment where food is scarce. Ketones are characteristic of fasting and prolonged fasting is usually due to famines. Studies of the children of mothers born during famines show they grow up much more prone to Type 2 diabetes than other children.

Anni said...

thank you for your response earlier! My readings continued to be around 100 mg/dl for fasting glucose when I tested them. My antenatal clinic thought I didn't need extra surveillance and should only measure my values occasionally after the initial monitoring period. At ultrasounds and doctor appointments, I was told my baby seemed to be of normal size, which reassured me, and since I suspected having MODY2 (in which case the hyperglycaemia shouldn't be treated in case the foetus has the same mutation), I didn't follow a strict diet at all.

What then happened was that a couple of weeks ago, I ended up having a very large baby! My pregnancy went on until the 42th week (he was supposed to be "normal size" so I wasn't induced or even checked earlier) and even on the day of labour every one assumed he would be a normal size for his weeks. Only upon the delivery did we find out that he was a whopping 5 kilos (11 lbs) and 58cm (22.8 inches)!! Luckily everything went well and he was born healthy. However, I do wonder what on earth has been going on with my glucose values, if he was so large. I did eat an unfortunate amount of ice-cream at the end of the pregnancy and could've been much stricter with my diet (I would've been if I'd known), but none of my values seemed that high when I measured them, apart from the consistently highish fasting glucose of course.

My initial thought was that I had MODY2 and the child didn't inherit it, which then caused him to have elevated insulin levels due to my higher fasting glucose. However, I've now found out that also my father (who has the same high fasting glucose and normal 1h postprandial values, and her mother was diabetic in later life) was also born around the same size. This doesn't fit the bill re: MODY2 (since if the foetus does have the same mutation, his size shouldn't be affected by the mother's high values, based on my reading at least), so I'm not sure if we could have some other form of MODY instead. As a new mother with a big hungry newborn, I haven't had much time trying to think this through yet, but I'd like to get to the bottom of it, as it seems so strongly genetic. If you have any ideas as to whether this could or couldn't be some form of MODY, I'd love to hear your thoughts. I'm also trying to enroll in a local study researching the MODY genes and their effect on insulin resistance to shed some light on this issue.

Thanks so much,

Jenny said...


I'm so glad to hear your baby turned out okay, though I don't envy you delivering an 11 pound baby. My two 9 pounders were challenge enough!

Looking forward, I would suggest that you keep monitoring your blood sugar after eating to see what the pattern is. But if you aren't seeing diabetic levels, you won't be able to get any help from doctors. If you do see an unusual pattern, your best bet would be to see an recently trained pediatric endocrinologist associated with a university medical school, as those doctors tend to be the ones who are most knowledgeable about unusual forms of diabetes.

But even there, little is known. So the best thing to do is to focus on keeping your blood sugars (an those of your children) as normal as possible, which should avoid the problems caused by abnormal blood sugars.

That is what I have had to do. Doctors don't have the time or curiosity needed to figure out what is actually going on in an individual unless it poses an immediate threat to life.

Trix said...

Hello Jenny,

I'm an endocrinologist that runs a diabetes in pregnancy clinic. Elevated fasting blood sugars are as concerning as elevated post-prandial readings. The current target for FBS is < or = 5.0 mmol/L. Two or more readings outside target in a week warrants treatment. A typical regimen would consist of an intermediate insulin such as NPH given at bedtime.

Anonymous said...

Hi Jenny,

I just wanted to give an update, since you've been so helpful with my blood glucose issues. My baby is now almost 5 months and doing very well - still far larger than average, although his growth rate has been normal, it's just that he was so tall to begin with. Interestingly enough, he's been fairly lean even at birth (despite his weight) and still now.

I haven't followed my blood sugar after the pregnancy, but shall do when I can afford more testing strips. I did however manage to enrol in a MODY study which recently started in my country (how lucky for me!). Last week I went in for a myriad of tests, which included genetic testing (for all MODY types I believe), a 2-hour OGTT with glucose and insulin measurements and lots of other things. I'm getting all my results by post once they're in, and can't honestly wait!

My sister also took part in this study, and interestingly enough our OGTT results differed significantly. (This probaly doesn't matter a huge deal, but my BMI is now 20 and I'm 27, my sister is the same age, BMI 22, though more athletic than me). We both had relatively high fasting values (5.4 mmol/l), but post-prandial were very different. I only got to have a quick glance at them during testing, so I might have got some of my facts wrong. However, I think I had a very high spike at 30 minutes (over 9 mmol/l) which then plummeted fast to normal levels (ultimately to 4.3 and then up again to 6.0), whereas my sister's just plummeted almost straight away and went extremely low, 2.9 mmol/l at their lowest. I have no idea what's going on with us, but look forward to getting our test results. I'm pretty sure my 30 minute value was much higher than my 1h value, and I wonder if this might explain why my baby was so large despite supposedly okay at-home values, which were all 1h pp. Although of course you can't really compare the effects of a glucose drink in OGTT with those of a proper meal, so I would have to test at home if my 30 min pp values normally differ much from 1-hour pp. Not sure what that would mean exactly though.

I'll keep you posted if we find out anything interesting from this study. Thanks again for all your help!


Anonymous said...

I know that a1c is not a reliable marker but from studies what seems to be the non diabetic average? How much does a1c increase during non diabetic pregnancy? Also the fasting and post meal numbers listed here do they apply just to everyday eating or the ogtt also ?

Jenny said...

Holly, I'm not sure what the normal A1c is considered to be in pregnancy. Usually doctors just administer the ogtt and don't understand the impact of post-meal numbers, but I would assume that for pregnancy as in non-pregnant states the best results come from getting those numbers after meals, too.

kisarita said...

while its good to know what normal is, i'm afraid you're off base with your suggestion of changing the "target" for pregnancy, which would mean medicating large numbers of women. to do this you need not only to know what "normal" is, but what level of abnormal is detrimental. you have not put forth any evidence that medicating women to acheive such levels will produce better outcomes at all, especially considering the very small difference in outcomes by pregnant women who are below the current treatment thresshold.

Jenny said...

kisaria, It isn't "My" suggestion to change the target. It's the suggestion of those whose research I cited and of other experts who published commentary on that research.

You can lower your blood sugar in pregnancy by watching your carbs. Medication is not required. And the better your blood sugar during pregnancy the more likely it is that your fetus will develop with normal insulin resistance.

There is quite a bit of data showing that exposure to higher than normal blood sugars in the womb predisposes children to obesity in later life. My

Unknown said...

What about Metformin during pregnancy---does it continue to be effective? I'm curious because as pregnancy progresses doesn't insulin resistance worsen?

Jenny said...

Anna, I don't know the answer to that question. You would have to discuss Metformin with your OB/GYN. Years ago they took pregnant women off all meds except regular human insulin, which seems like good advice to me but I don't know what the practice standards are now.

kisarita said...

addendum to last note: in addition to highly restrictive diets

Unknown said...

Jenny, I just wanted to thank you for this blog. I was non-diabetic prior to pregnancy. I am now 14 weeks into my pregnancy. I wasn't feeling well one day so I went in to see my OBGYN. Since I was in there at 8 am and hadn't eaten anything she decided to see what my glucose was. She found it to be 135 mg/dl. She decided to schedule me for an OGTT the next day. My one hour was 183, 2 hour 171, and 3 hour 159. I don't remember what she said my fasting was. She's diagnosed me with GD and is treating me for it but wants to see me at a post delivery follow up for another OGTT, auntoantibodies check, c peptide levels, and a a1c reading. I'm not sure what she's looking for with those.

Galena said...

Hi Jenny,
I am 27 week and today I had the OGTT. The results were a bit surprising: 90- fasting, 129 after 1 hour and 159 after 2 hours. To my understanding the value after 2 hours should normally be less than the value after 1 hour. Is that correct and if not could you give me any explanation? Thanks a lot in advance!

Jenny said...

Galena, Mostly blood people will see higher sugars at I hour but not all. Blood sugar is very variable. Your liver may be dumping glucose for some reason--perhaps the physiological stress of the test. I wouldn't worry about it too much. Just see what the doctor suggests.

Galena said...

Thank you so much, Jenny! Yes, I will talk to my gynaecologist but he is not a specialist....To my understanding the glucose drink is something which should be absorbed very fast in the blood and the jump should be seen immediately, correct? As my mom has diabetes I asked her to measure my post meal sugar, 30 min, 1 h, 2 h. There was nothing like that, the numbers were declining, so for me this is a possible error. She checked me over 5 times... What do you think? Thank you so much again!!!

Jenny said...


Tell him about your home test. It could be an error or one of the many odd things blood sugar does. The doctor has seen many many women's OGTT results and should be able to sort this out for you.

Galena said...

Thank you so much, Jenny! I will do so.
Have a great Sunday!

Mohammed Rizvi Uvais said...

Hai jenny
Now I'm 34 week pegnant lady. I done gtt test, there for the fasting blood suger I got 76.6 mg/dl. After 1st hour blood suger level is 230 mg/dl and after 2nd hour blood suger level is 216.00 mg/dl. Is that effected to my baby? Before 34 week I do not have this range. When doctor scans baby and tall she is ok. But I'm fear @ my blood suger. It will effect to my baby?

Jenny said...

34 week pregnant lady.

I assume that your doctor is now treating you for those gestational diabetic blood sugars. If that is the case, your baby should be fine. The main problem that high blood sugars cause babies in the womb is that they make them grow very large which can make for a difficult delivery. Also those high blood sugars can make the baby more prone to have high blood sugar themselves as they grow up.

However, I had two very diabetic pregnancies that were not treated at all by my doctors because my fasting blood sugars, like yours, were normal, and both my children turned out fine though they were very large at birth.

For the now and the future you can do a lot to improve matters, too. Eat less starch and sugar through the rest of your pregnancy replacing them with protein and fat. This will lower your blood sugar and be very helpful to your baby.

Wishing you a safe and happy birth!