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Preparing for the 3 Hour Glucose Test

Hi, I am 25 weeks prego and last Sunday, I had my 1 hour glcose test done. Results came back at 179 which was beyond the normal end of 139. I was not told to fast since it was a "random" test. However, not thinking, I did have an apple crumb muffin at 10, a teriyaki chicken burger and fries dipped in teriyaki sauce for lunch and took the test at 2:30. Do you think that could have made my number go up? In addition, now I have to do the 3 hour test this Sunday. I was told to eat a half a sandwich and milk/juice 10 hours the night before and fast at midnight to do the test at 8am. Was wondering why would they want me to drink milk/juice before the test? Also, I have read other people's posting and medical/hospital websites saying to eat extra carbs or candy bars the 3 days before the test, which sounds very counter-intuitive to me. I would think to avoid or lessen sugary/carby food days before the test. Can anyone explain the reasoning behind this? I'm praying the 3 hr test will come back normal... just dreading being on a strict diet and having to prick my fingers. Thank you!

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Don't drink anything (other than water) before the test. You really need to fast. I would also caution against anyone telling you ways to get around the test (the carbs a couple days before) because the test is there to determine if you have gestational diabetes. Fooling the test just leaves you undiagnosed if you have it, which could be dangerous to both you and the baby. Diabetes is very serious and could lead to birth defects if untreated. While it is not fun (I was diabetic with both of my kids), you do need to find out if you have it so you can be treated and have a healthy baby.

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Hi K.,
I had the same test done with my last child. It's no big deal. Don't worry about what you do or don't eat in the days before the test. Just be sure to fast after midnight. The carbs/sugar thing is probably to see (as someone mentioned earlier) if your body can tolerate the worst case scenario...binge eating! However, any manipulation of diet either way, binging or starving, will skew the test and then you don't know if it's right or wrong. So just eat the way you normally would. What do you normally eat for dinner? Eat that. Then nothing after midnight, not even water, because that can make your body start producing insulin, too, thinking that it's going to be getting some nutrition. By the way, I hate to burst your bubble, but 3 hour glucose tolerance tests usually are venous blood draws, not fingersticks. It may be different where you are, but a blood draw is the standard. Still no biggee. Just roll with it. Also, they don't usually make you sit there and wait the entire time. You have an hour in between each stick and they should let you go run errands or whatever in between as long as you're back in an hour. If you'd rather just sit there and veg out, more power to you. But usually you can get out and about if you'd rather. And yes, eating probably did skew your original random blood test, but 179 is still high for a random test even after eating, so prepare yourself for the possibility of dealing with Gestational Diabetes. Again, not the end of the world, and all will go back to normal after delivery. Take it in stride. We're women, we're tough. If our ancestors could do it and live through it without the conveniences and medical knowledge we have now, we can do it even better! Anyway, you're more than 1/2 way there, so you would only have to deal with it for 15 weeks...yeesh, that's just a tick in time! Good luck, God bless, and, as Castanza's father says on Seinfeld...."serenity now!"

If it was me I would eat just as I would normally eat throughout the week. I would want the test to be as accurate as possible. If your 3 hour test comes back that you need to be on a strict diet, then at least you'll know that you didn't alter your diet in any way and you can have piece of mind that your baby will be healthy. I had to take the 3 hour test and my results came back border line, but they didn't put me on a diet. I just had to eat one cupcake instead of two!!! LOL!!! Just kidding. The doctor will just ask you to watch your sugar and you'll be fine. Relax and enjoy!

Don't drink anything (other than water) before the test. You really need to fast. I would also caution against anyone telling you ways to get around the test (the carbs a couple days before) because the test is there to determine if you have gestational diabetes. Fooling the test just leaves you undiagnosed if you have it, which could be dangerous to both you and the baby. Diabetes is very serious and could lead to birth defects if untreated. While it is not fun (I was diabetic with both of my kids), you do need to find out if you have it so you can be treated and have a healthy baby.

I would take the 3 hour test, but call your dr. and explain about the first test. I would also let the lab techinician's know about the 1st test and ask about it. Ask the question's get the answers. One positive thing about it is at least you will know 100% if you have diabetes with this pregnancy. Good luck.


I have to agree with Beth- Follow the Dr.s instructions and do not try to cheat the test by running errands or walking around between the blood draws- the late snack is to get you through in the morning- you will be hungry.
I had GD and while it is just one more thing to put up with during pregnancy- the whole time I kept reminding myself I was doing it for my baby- I would hate to think the harm I could have dome to her if I had cheated the test becasue I did not want to prink my finger a few times a day or watch what I eat- Plus the added benifit for me was I gained less then 20 pounds during the pregnacy- and was below my prepregnancy weight by the time my daughter was a month old.

Hi K.
I'm a liscensed Lab Tech here in Calif.. I'm not sure why anyone would tell you to "eat" prior to a 3hr test. Our protocol is that mommies fast prior to the test..here's how it goes...we would first draw a blood sample and run it ..if the results come back o.k. we then give 100 grams of drink, if they come back high we notify the Doctor and follow their directions. If results are normal we instruct you to return for a blood draw at the exact hour of the last sip of drink.. between that time you are to have nothing to eat or drink..which could compromise the results.. it's a long day for mommies, some bring things to do read, knit etc. We do however instruct you not to leave the facility...good luck

Hi K.! I had to take the 3 hour glucose test with my second child and I ended up having gestational diabetes. It doesn't matter how you eat before the test, if you have gestational diabetes it will come out in the test. During the week before the test I did not eat any carbs because I thought it would help and it didn't. I was upset at first, but I learned how to eat properly and test my blood and it wasn't so bad. Bring a book or an ipod so you are occupied for the three hours. Oh, and the fasting the night before is pretty standard. I don't know anything about drinking the milk though. Good luck!

I've never done this test, but I'm just going to hazard a guess that they are also looking to see if your insulin response is normal or prediabetic. It would be good to ask them exactly what they're looking for and what it means.

Dear K.,
Gestational diabetes is nothing to fool around with. I have two friends with zero diabetic history and they both had gestational diabetes with each of their pregnancies. The good news is, once the babies were born, their insulin/sugar levels went back to normal.
My first glucose test came back wacky and I had to do the 3 hour test. I had already had so many complications that I didn't think I could take one more thing. I followed all the eating and fasting instructions, etc. I got really scared because the glucose knocked me out. They put me in a bed and took my blood on schedule and I slept through the whole thing. It freaked me out! Anyway, my levels came back fine and my doctor told me that going to sleep was actually a good sign, that it happens often, and it meant that my body was doing what it was supposed to do with all that extra glucose in my system.
So, for now, don't worry. Eat and drink exactly what your doctor tells you to eat and drink and when. Don't be alarmed if you get really drowsy, and don't be alarmed if you don't. When the numbers come back, you can go from there. Chances are likely that all will be fine.
Please let us know how it goes!

UGH! i hated the glucose test and in fact I cheated. I don't drink soda and I watch my sugar grams too... why must I drink this high fructose corn syrup concentrate and introduce my body to a ton of sugar that I wouldn't normally eat. I realize I'm not of the average, but I would say lay off the sugary substances.... teriyaki sauce is very high in sugar, so are potatoes, and muffins... based on what you wrote... I can imagine what the rest of your diet is like. gestational diabetes doesn't always go away and it can lead to further issues. get your sugars under control and no, I would NOT consume extra sugars before the test... but then again I go with my own intuition and training in holistic nutrition as opposed to what the Medical doctors have to say... and yes, my son is completely healthy and happy and born with no complications with a very easy labor and delivery.

My dr and the test lab all told me to fast the night before. Water only. I went kookoo as I also take thyroid meds and being prego of course we eat around the clock. Any food can change the results of the test. I had food iwth me at the appt so right after I could chow down. I hope your other test come back neg.

Good luck,

SAHM/zombie 40yrs old with 2 fun loving little boys. 3yrs aned 8 months.

I ended up having to take the 3 hour test in 2 of my pregnancies and I'm terrified of needles so you can imagine I did not enjoy the experience. Both times everything came out in the normal range the only reason I even had to take them is because I messed up on the 1 hr test. The first pregnancy I stopped at starbucks before going to the dr to do the 1hr & the venti mocha is what caused my levels to be so high. And then with my next pregnancy I decided that even though they don't tell you to fast I didnt want to risk eating anything that would ruin my test so I fasted. And I fasted for too long, because then my blood sugar went up because I hadn't eaten for so long and I had to take the test again.
So having experienced that twice now... my advice to you is the day before the test eat your normal dinner at whatever time you would eat it then around 11 or so have a light snack whatever you would normally have. The reason for the milk or juice & a sandwich is because it will fill you up without being too filling or too sugary. Don't have a handful or cookies & a pepsi or anything crazy but eat something you think will tide you over till the test is over.
On the day of the test I also suggest that you go first thing in the morning as soon as you wake up. Bring a book or something to occupy your time & a good friend who will take you out to eat afterwards. Something about not being able to eat & drinking that horrible sugar drink made me so incredibly hungry all I could think about was food the entire time I took the test.
Good Luck & I hope everything turns out perfect!

Hi K.,

I think the fact that you ate the MOST sugary, carb filled meals right before your test DEFINITELY impacted your results. I had gestational diabetes during my last pregnancy and am going in for the 3 hour glucose test next week. I would just suggest to watch what you eat and eat sweets/carbs in moderation. The reason for drinking milk/juice the night before is so your sugar counts don't dip too much since you will be fasting for your test.

Good luck!

I had GD with my first pregnancy and not again with my 2nd pregnancy. My friend had GD with all 3 of her children.

Here is the bottom line: you can't rig the test, you shouldn't try, and stress (& lack of sleep because of it) will make it be way worse than it is.

My advice: EAT NORMALLY in the days leading up to the test. Eat exactly how you eat every other day of your life. If you are following a healthy pregnancy diet it won't make or break your blood glucose test. Make sure you fast the 12 hours before you go for your first draw, in which case, have dinner the night before then stop eating. Go in to the lab the moment they open & make sure when you check in that they know you are on a timed GD test so that they can get your first draw done right away and start the test. The syrup you drink this time will be stronger than the last. They will draw your blood at fasting, one hour after the drink, two hours after the drink, then three hours after the drink. What they are looking for is not one significantly high number but rather what your blood sugar does over time. Yes, high fasting is BAD (note: FASTING... in other words, what your blood sugar is when you haven't had anything to eat!) but they will also look at how quickly your blood sugar will drop in the subsequent hours after having had the drink. THAT is the crucial thing.

Meanwhile don't stress. Either you have GD or you do not. If you do you need to know how your diet & exercise is going to help your health & especially the health of your child for the remainder of your pregnancy. It is a VERY serious health matter. If you don't have it, then you just spent 3 very long hours in a waiting room. Oh well. Its all part of the process!

Good luck :) Update us all please when you get your test results!!!

HI K.:

I have not heard of a specific diet prior to a 3 hour test. I was diagnosed with GD with my second pregnancy. I wanted to respond to you to tell you that if you do have GD, it is a challenge, but not a huge difficulty. I actually was able to manage my GD with diet and exercise and it was a good thing.Testing was a drag, but mom's can get through anything for their kids! I had to make sure to take better care of myself (I also developed asthma during this pregnancy). When my son was born he was 8 lbs 14 oz and was perfectly healthy. My son is now six and I am still very careful about my diet and exercise because I do not want to develop diabetes, and again, I see this as a good thing.

I just want to tell you to take the test however you are asked and to know that even if you do have GD, that it is much better to know so that you can manage it.


I am pregnant for the 3rd time and have had gestational diabetes every time... so very familiar w/ the tests!

The way it was explained to me (and now makes sense since I test my blood sugar 4 times a day, including a fasting test as soon as I wake up) - you need to start the test (and your day) with level blood sugar. If you have a balanced snack before bed you have the best chance of that. If you don't have a snack, or try to just have a protein, your blood sugar will drop over night and then can suddenly spike. So instead of starting the morning w/ low blood sugar or a normal level, it can actually be spiked and skew the results.

I'm not sure about the 3 days thing, I test my blood sugar 4 times a day after every meal and it pretty accurately reflects my last meal (i.e. if I have a bad breakfast and test bad, but am back on track at lunch, my lunch test will reflect that).

Hope that helps!

K., I just failed mine, and have been seeing a nutritionist. I was not told to eat extra carbs or candy bars the 3 days before the test, so I don't know exactly why they would tell you that, but it made me think of something that the nutritionist told me. She said that I should not cut out carbs all together because then my body will start creating Keytones which is like sugar and so maybe that is why they are telling you to eat more before the test cause then your body will not be creating it's own? I can tell you the diet sucks, but the pricking of the fingers is not so bad. I hope that you do good on the test. They did not give me any set foods to eat before I took my tests, and my 1 hour test was supposed to be fasted. I would imagine that what you ate before the one hour test did put you over. Teriyaki is really high in sugar, and fries are carbs which would put you up to, not to mention the bun, and whatever you had to drink if it was a regular soda, or a milk shake or something??? Anyways - I hope that you do well on your test! Good Luck, and hang in there, it's not as bad as it sounds if you do end up having gestational diabetes!

Hi K.! I just went through the same thing last month. My doc gave me a "diet" to follow for 3 days before the test: basically, eat as you normally do, but add some extra carbs in (2 extra pieces of bread plus 1/2 cup raisins; or extra rice or noodles plus 2 medium apples; it was a "mix and match" type thing). It does sound counter-intuitive, but the doc said the reasoning was to load you with extra carbs (stick with healthier ones, candy bars were not on the list!), to see how your body is processing the extra load. I guess it gives more accurate test results.
My results came back normal. I have a lot of friends that have had to do the 3-hour, as well, and all of those have come back normal. I went through the 3-hour with my 1st pregnancy, again with normal results. Hope this makes you feel better!
I was talking to a couple of people that did have gestational diabetes, and they had completely healthy pregnancies and babies - they said you end up with more ultrasounds, and a more controlled diet, but that there was never any worry about the baby or pregnancy.
Good luck to you, and congrats on your soon-to-be little girl!

I think you should eat as you normally would the night before. you don't want to try and fool the test. also take a laptop and a movie with you because you can't leave for those three hours. GOOD LUCK

I had to do the 3 hour test with both of my pregnancies and both came back fine. I was told not to eat anything 12 hours before the test and to lay off of juice and to watch sugars a couple of days before the test.

Doing this test is a big pain...mostly because you have to sit there the whole time...but it will be woth knowing.

I had to do that too! I wasn't told to fast before the 1 hour test and I had a fruit smoothly for breakfast and a peanut butter/jelly sandwich for lunch! Of course, based on my results, I was scheduled for the 3 hour. I ate a normal dinner the night before and just had tea and water the morning of and my results were normal. If you feel confused about what to eat then just ask your doctor to clarify the specifics. Good luck!

I think the reason they want you to eat carbs or sugars is so that they can see how your body is able to process them. Both pregnancies I had to take the three hour test and then came back within normal range. Try not to stress on it. It's not fun, but it is supposed to be a lot more accurate than the one hour. The odds are it will turn out fine. Best of luck!

IF you truly have GD, a longer fast is only going to make your liver produce more sugars to keep you from being hypoglycemic. GD is unlike regular diabetes in that the placenta emits an insulin-resistant hormone and your pancreas can not produce enough insulin to counteract the hormones. Regular diabetes, your pancreas just doesn't produce enough insulin. If you do not have GD, your body should process the sandwich and milk/juice in a "normal" way and the test will turn out fine. I have had GD with both my pregnancies. Honestly, it is not as bad as you may think. I eat constantly and end up losing weight after the baby is born. During the pregnancy, I usually remain the same weight even though the baby is growing normally. It is best to find out early on if your glucose is off. You don't want a 10lb baby and have to have a c-section. Good luck on your test. If you want suggestions on food choices if it comes back positive, feel free to e-mail me. I brought a water and my laptop to the lab and watched a movie to pass the time.

I too had to do the 3 hour test and was not happy about it. I had the one hour and had eaten beforehand as well and was above normal. My recommendation is to not eat the night before, have the test as early as possible that next morning. Each time you draw blood, instead of sitting and reading a book, go for a walk outside to get your blood going. Mine came back completely normal after I did this. Also, on the third blood draw, take a walk to a spot where you can get some food because you are going to be very hungery after 3 hours!!
Good luck.

Hi K.. I also had to do the 3 hour test and it came back fine. When I did it the lab waiting area was filled with pregnant woman reading there books and magazines. Alot of people I know had high numbers the first time and had to do the 3 hour test and only 1 of them was diabetic. Try not to stress about it like I did. Good luck and bring a book, its boring!

ok here's why :) I'm a phlebotomist so I know a little about this (plus a mom of 3).

If you go too long without eating it could drop your sugars to an abnormal low and then the test wouldn't be completely accurate. It wouldn't accurately show how your body is reacting to the sugar in your blood.

I did the same thing when they told me not to fast I had a good breakfast and nice lunch and then my glucose came back high so I had to take that test where you fast 12 hours and they draw your blood every hour for 3 hours after you drink some goop they give you. I Had a normal glucose test on that one. Don't eat extra carbs or candy the days before the test eat the 1/2 sandwich and have a drink and then fast till the test. only water in the morning until the test. It should be fine.

I had gestational diabetes w/ my first pregnancy and just took (and failed) the 3 hour test.

Eating ANYTHING will change your numbers. You need a fasting number or you might have a really sky high fasting number, which will cause the MD to think you have GD w/ major problems with your fasting number and might even suggest medication right off the bat.

The sandwich and milk get some carbs into your system. The MD wants to see how your system handles this for a period of 8-10 hours, thus your fasting number. If you stop eating at say, 7pm, the number can be superlow at fasting, also not good. It gives them the most accurrate number possible.

I have never heard to eat candy before taking a blood-sugar test. I agree, how counterintuitive is that??

For me, the diet was very manageable. I am a memeber of Kaiser and they have a wonderful regional support team of nurses that give you lots of ideas about meals. YOu just have to have a small number of carbs w/ each meal. It was really ok last time round and I've just started the diet again this week and so far, pretty manageable. Pricking you finger regularly is just a chore, just like pumping- it's something you gotta do. Good luck, I hope it all works out.


I'm so glad you asked this question because I'm in the same boat with my 2nd pregnancy - I'm at 29 wks & have to take the 3-hr test next week sometime.

The only thing I have to suggest is to definitely bring reading materials, but also something you don't have to concentrate on, like a laptop with a movie or a portable DVD player. A friend of mine had to take the 3-hr test twice because of her genetic history of diabetes & the 1st time she only brought reading materials. She said it was difficult because you're so hungry that drink sits in your stomach & it makes it more difficult to concentrate on things like reading a book. So magazines, anything that's "light reading" would be good. The 2nd time she brought her laptop with a movie & that made the time pass much easier.

Just a suggestion :> Good luck!

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