Week 27: Gestational Diabetes

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This is your Pea in the Podcast for week 27 of your pregnancy. I'm Bonnie Petrie joined by Dr. Laurie Swaim, an obstetrician with Houston Women's Care Associates in Houston, Texas.

So is this week the beginning of the third trimester? Or is it next week? Well it depends on whom you ask. Many people will say it's this week but since you may not deliver until the end of week 40, or beyond others, will say next week. All that really matters to you is what your doctor or midwife may say so ask them. Regardless it is time for one of the less pleasant tests of pregnancy, the glucose challenge test, or GCT. "The one hour GCT is a 50 gram glucose load that is given to women to screen them for gestational diabetes. Sometimes, like I mentioned earlier in some of our discussions, we do it earlier for women who are specific risk for gestational diabetes. That would be women who are older, maybe women who are overweight, not a little overweight but really overweight, women with a history of gestational diabetes past, women with a history of a big fat baby in the past, and when I say big fat that's fetal macrosomia, greater than 90th percentile at gestational age. There are certain ethnic backgrounds that are at greater risk. By the way if it was negative before I would still repeat it now. The reason we do it now is because the placenta produces hormones that makes them more likely to be diabetic, one of the notable is human placental lactogen (HPL), and it's produced in its greatest quantities between 24 and 28 weeks so you really want to do the test when you're most likely to find the positive result."

So if you haven't had it already, you may have it this week. Dr. Swaim says you don't have to do anything special to prepare, "You don't have to be fasting, there's no special diet needed but it's just not smart to eat a bunch of sugar before you walk out the door either. So they have the test, they drink the stuff, they can't eat or drink anything, no to gum chewing and no water or anything for an hour and then their blood is drawn. Typically at this visit we'll also re-check for blood count, the hemoglobin, to make sure no one is developing any significant anemias. In the event that the test is normal then good. If it's abnormal it does not mean the patient is diabetic, it means she might be, in which case we will do a 3 hour test. I will say that if it is horribly abnormal most of us won't make the woman endure a three hour test, we'll say 'guess what you're diabetic', and then you move on into the treatment phase or the management phase. So the three hour test is 100 gram load, you do have to be fasting but we used to tell people they had to carbo load for a few days but that's no longer thought to be necessary, it hasn't been for a number of years. So you come in fasting, get your blood drawn, drink your drink, have your blood drawn every hour for 3 hours and then there are certain values that we look. The diagnosis of gestational diabetes really should be made if there are two abnormal values but there are some people who use one abnormal value and that's that. But it's pretty important."

Dr. Swaim says you test for gestational diabetes because if your body can't effectively use the glucose floating around in there your baby takes it on. "The baby has no problem dealing with all the glucose and glucose really crosses the placenta and so the baby takes all the glucose like 'thank you very much' and packs it on. So anyways babies can be much larger and they're really cute but the problem is they don't fit through the door necessarily so that's the big risk. After they are born, sometimes they have trouble keeping their own glucoses up too because they're so used to using mom's that they're not really used to producing their own the way they should be. So sometimes those are the babies who might need actually IV fluid or need to be given a bottle or whatever which drives me crazy because breast milk, by the way, has plenty of glucose in it but immediately after their born kind of thing." So out of control blood sugar is not good for you or your baby. Now if you test positive for gestational diabetes, don't worry, it is manageable. Dr. Swaim says you get started right away, "in general we send the patient to a dietician and we have them record their glucoses 4 times a day and keep up their exercise and those are the first steps." You get used to pricking your finger four times a day fairly quickly and the gestational diabetes eating plan is really not difficult to follow, it an be a little overwhelming though when you first look at it. A walk after you eat can have a great effect on your blood sugar level so if you try doing that it really helps. If you're not able to control your gestational diabetes with diet and exercise though your doctor may recommend insulin shots.

So who's most likely to get GD? "Women who are probably over the age of 35, women who are obese, women with a history of gestational diabetes, women with confirmed family history, women who've had a history of a macrosomia or a baby greater than the 90th percentile and there are certain ethnic groups, I think American Indians are at a greater risk." But guess what? Everyone gets tested because really anyone can get it no matter their age, shape, size or ethnic background. "That's why you screen people because if we did it based on risk factors we'd miss a lot of people, that's a good point. If we looked at someone and said 'no you're too skinny, it's not going to happen', well weird things have happened." But the good news is gestational diabetes usually goes away after delivery. You will, however, have a greater risk of getting GD during your next pregnancy and also later on in life you may be at higher risk for diabetes.

Well, whether this is the end of the second trimester or the beginning of the third the honeymoon is over. You may not be feeling quite as energetic as you have been, one reason for that could be that you're short of breath as your uterus expands upward and pushes your intestine ahead of it. Your lungs just don't have room to fully expand anymore and it may feel like you can't get a good breath. Hormones are helping you out a bit by helping your circulatory system work more efficiently pumping all that extra blood volume you now have to you and your baby, but that is a lot of work. As Dr. Swaim mentioned you are at greater risk for anemia right now, which could also make you feel tired. Your center of gravity also may be a little off, making balance a bit of an issue as hormones loosen your joints, this could lead to twisted ankles so be a little more careful.

Your baby's brain development goes into overdrive this week and it will remain that way for the rest of the pregnancy. All his or her organ systems are fully functional now; its eyelids will begin to unseal themselves as the retna develops so the little one will get a partial peak of its watery home. The little one now weighs about 2 pounds and is around 9 � inches long. If it was born today the baby would need time in NICU but the risk of complications and handicaps go down every week until its due date. You are now 27 weeks pregnant; you have 13 weeks to go until week 40.

That's your Pea in the Podcast for week 27 of your pregnancy. Dr. Swaim and I look forward to talking to you again next week. Enjoy this week. For a transcript of any of our Pea in the Podcasts go to our website peainthepodcast.com. For Pea in the Podcast, I'm Bonnie Petrie, thanks for listening.