What is gestational diabetes?
What is gestational diabetes?
This is a type of diabetes that some women develop during pregnancy. Between 2 and 7 percent of expectant mothers develop this condition, making it one of the most common health problems of pregnancy.
When you eat, your digestive system breaks most of your food down into a type of sugar called glucose. The glucose enters your bloodstream and then — with the help of insulin, a hormone made by your pancreas — provides fuel for the cells of your body. Like the type 1 and type 2 diabetes you can get when you're not pregnant, gestational diabetes causes the glucose to stay in your blood instead of moving into your cells and getting converted to energy. Why does this sometimes happen when you're pregnant?
During pregnancy, your hormones make it tougher for your body to use insulin, so your pancreas needs to produce more of it. For most moms-to be, this isn't a problem: As your need for insulin increases, your pancreas dutifully secretes more of it. But when a woman's pancreas can't keep up with the insulin demand and her blood glucose levels get too high, the result is gestational diabetes.
Most women with gestational diabetes don't remain diabetic once the baby is born. Once you've had it, though, you're at higher risk for getting it again during a future pregnancy and for becoming diabetic later in life.
How does having gestational diabetes affect my pregnancy?
These days, most women who develop diabetes during pregnancy go on to have healthy babies. Your practitioner will monitor you closely and you'll most likely be able to keep your blood sugar levels under control with diet and exercise, and by getting insulin shots if you need them. But poorly controlled diabetes can have serious consequences for you and your baby.
For most women with gestational diabetes, the main worry is that too much glucose will end up in the baby's blood. When that happens, your baby's pancreas needs to produce more insulin to process the extra glucose. All this excess blood sugar and insulin can cause your baby to make more fat and put on extra weight, particularly in the upper body.
This can lead to what's called macrosomia. A macrosomic baby may be too large to enter the birth canal. Or the baby's head may enter the canal but then his shoulders get stuck. In this situation, called shoulder dystocia, your practitioner and her assistants will have to use special maneuvers to deliver your baby. Delivery can sometimes result in a fractured bone or nerve damage, both of which heal without permanent problems in nearly 99 percent of babies. (In very rare cases, the baby may suffer brain damage from lack of oxygen during this process.) What's more, the maneuvers needed to deliver a broad-shouldered baby can lead to injuries to the vaginal area or require a large episiotomy for you.
Because of these risks, if your practitioner suspects that your baby may be overly large, she may recommend delivering by cesarean section. Fortunately, only a minority of women with well-controlled gestational diabetes end up with overly large babies.
Shortly after delivery, your baby may also have low blood sugar (hypoglycemia) because his body will still be producing extra insulin in response to receiving extra glucose from you. Your delivery team will test his blood sugar at birth by taking a drop of blood from his heel. If it's low, you'll want to feed him as soon as possible, either by breastfeeding or giving him some formula or sugar water. (In severe cases of hypoglycemia, he might be given an IV glucose solution.)
He may also be at somewhat higher risk for jaundice, polycythemia (an increase in the number of red cells in the blood), and hypocalcemia (low calcium in the blood). If your blood sugar control is especially poor, your baby's heart function could be affected. Some studies have found a link between severe gestational diabetes and an increased risk for stillbirth in the last two months of pregnancy. And finally, having gestational diabetes makes you about twice as likely to develop preeclampsia as other pregnant women.
Will my baby be monitored during my pregnancy to avoid complications?
Your practitioner may want to monitor your baby more intensively during your last two to three months of pregnancy, depending on the severity of your diabetes and whether you have any other obstetric problems. She'll explain how you should begin counting your baby's movements during your third trimester so you can alert her immediately if you sense that your baby is less active.
If you're unable to keep your blood sugar under control or it's high enough that you need insulin, or if you have any other risk factors, you'll probably begin to have fetal heart monitoring (nonstress tests) or periodic ultrasounds around 32 weeks to check on your baby's well-being. (This kind of ultrasound is called a biophysical profile.) If you can keep your diabetes well under control without insulin and you have no other problems, you might not begin these tests until your last few weeks or until your due date.
Your practitioner may also order an ultrasound around 29 to 33 weeks to measure your baby and estimate his weight. At that point, if your baby is already getting too big, you might be started on insulin. She may order another one closer to labor if she suspects your baby is large, but ultrasound is not usually very accurate at determining a baby's size late in pregnancy. Depending on your circumstances, you might be induced before your due date, or your practitioner may recommend delivering by c-section.
NOTE: If your diabetes was diagnosed in the first half of your pregnancy, it's more likely that you had unrecognized diabetes before you conceived. In this case, your provider may order a fetal echocardiogram (an ultrasound that focuses on your baby's heart) because the risk of birth defects, especially heart defects, is higher if your blood sugar was high during the first eight weeks of pregnancy, when your baby's body was being formed.
How will I know if I have gestational diabetes?
You may notice that you're more thirsty, hungry, or tired than usual or that you have to urinate more frequently, but these are common, normal symptoms during any pregnancy. The fact is that gestational diabetes often has no symptoms. That's why almost all pregnant women are given a glucose screening to test for it between 24 and 28 weeks.
However, if you're at high risk for diabetes or are showing signs of it (such as having sugar in your urine), your caregiver will recommend this screening test at your first prenatal visit and then again at 24 to 28 weeks if the result is negative. If this test result is positive, it doesn't mean that you have gestational diabetes, but you will need to take a longer follow-up test for a diagnosis.
What factors would put me at risk for gestational diabetes? According to the American Diabetes Association, you're considered at high risk for this condition (and should be screened early) if:
• You're obese (your body mass index is over 30).
• You have a history of gestational diabetes (you've had the condition in a previous pregnancy).
• You have a strong family history of diabetes.
Some practitioners will also screen you early if:
• You're found to have sugar in your urine (your urine is tested at each prenatal visit).
• You've previously given birth to a big baby (some use 8 pounds, 13 ounces as the cut off; others use 9 pounds, 14 ounces).
• You've had an unexplained stillbirth.
• You've had a baby with a birth defect.
• You have high blood pressure.
Keep in mind that many women who develop gestational diabetes don't have any risk factors. That's why most practitioners will order the screening at 24 to 28 weeks for all their pregnant patients as a matter of course. On the other hand, a small number of women may be considered at such low risk that they don't need to have the screening test at all. You're part of this group if you meet all of the following criteria:
• You're younger than 25.
• Your weight is in a healthy range.
• You're not a member of any racial or ethnic group with a high prevalence of diabetes, including people of Hispanic, African, Native American, South or East Asian, Pacific Island, and indigenous Australian ancestry.
• None of your close relatives have diabetes.
• You've never had a high result on a blood sugar test.
• You've never had an overly large baby or any other pregnancy complication usually associated with gestational diabetes.
How is gestational diabetes managed?
It depends on how serious your condition is. You'll need to keep diligent track of your glucose levels, using a home glucose meter or strips. Eating a well-planned diet can help you keep those levels where they should be. The American Diabetes Association recommends getting nutritional counseling from a registered dietician who'll help you develop specific meal and snack plans based on your height, weight, and activity level.
Your diet must have the correct balance of protein, fats, and carbohydrates, while providing the proper vitamins, minerals, and calories. (Plan on little or no candy!) To keep your glucose levels stable, it's particularly important that you don't skip meals, especially breakfast.
This may sound daunting, but it's not so hard once you get the hang of it. And don't think of yourself as being on a "special" or restrictive diet. The principles of the diabetic diet are good ones for everyone to follow. Think of this as an opportunity to get yourself and your whole family into healthier eating habits. If everyone in the house is eating the same foods, you won't feel as deprived.
Studies show that moderate exercise also helps improve your body's ability to process glucose, keeping blood sugar levels in check. Many women with gestational diabetes benefit from 30 minutes of aerobic activity, such as walking or swimming, each day. Exercise isn't advisable for everyone, though, so ask your practitioner what level of physical activity would be beneficial for you.
If you're not able to control your blood sugar well enough with diet and exercise alone, your provider will prescribe insulin shots for you to give yourself as well. About 15 percent of women with gestational diabetes need insulin. It sounds scary, but remember that it's the high sugar and not the insulin that's dangerous for your baby. Recently, some practitioners have been prescribing oral medications (such as glyburide or metformin) instead of insulin for gestational diabetes, but the safety and effectiveness of these drugs is still a matter of debate.
Will I continue to have diabetes after my baby is born?
Probably not. Only a small percentage of women with gestational diabetes remain diabetic after delivery, and experts suspect that most of these women actually had undiagnosed diabetes before they got pregnant. To be sure, you'll need to have a glucose test about six to 12 weeks after delivery. This test requires an overnight fast and can be done at your six-week postpartum visit.
Does having gestational diabetes put me at higher risk for diabetes in the future?
Yes. About two-thirds of women who have the condition will go on to have it in future pregnancies. And a few studies have found that about 50 percent of women who get gestational diabetes will develop type 2 diabetes within the first five years after delivery. Your risk is highest if any of the following apply to you:
• You're obese.
• You had very high blood sugar levels during pregnancy (especially if you needed insulin).
• Your diabetes was diagnosed early in your pregnancy.
• The results of your postpartum glucose test were borderline (that is, they were relatively high, but not high enough to classify you as a diabetic).
Your practitioner will let you know how often you'll need your blood sugar tested, usually every one to three years if the results of your postpartum test are normal. Keeping your weight down, making healthy food choices, and exercising regularly can help you ward off the disease. You may also want to avoid using the progestin-only Pill for contraception after you have your baby. In women with recent gestational diabetes, it has been associated with an increased risk of developing type 2 diabetes.
Your child will also have a higher likelihood of childhood and adult obesity, and of developing diabetes. It's important to help him eat a good diet, maintain a normal weight, and stay physically active. Be sure your child's healthcare practitioner knows that you had diabetes during pregnancy.
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