Diseases & Conditions

Gestational Diabetes

Gestational diabetes is a type of diabetes that occurs only during pregnancy. Like other forms of diabetes, gestational diabetes affects the way your body uses sugar (glucose) — your body's main source of fuel. Gestational diabetes can cause high blood sugar levels that are unlikely to cause problems for you, but can threaten the health of your unborn baby.

Any pregnancy complication is concerning, but there's good news. You can manage gestational diabetes by eating healthy foods, exercising regularly and, if necessary, taking medication. Taking good care of yourself can help ensure a healthy pregnancy for you and a healthy start for your baby.

Fortunately, gestational diabetes is usually short-lived. Blood sugar levels typically return to normal soon after delivery.

For most women, gestational diabetes doesn't cause noticeable signs or symptoms. Rarely, gestational diabetes may cause excessive thirst or increased urination.

When to see a doctor
If possible, seek health care early — when you first think about trying to get pregnant — so your doctor can evaluate your risk of gestational diabetes. Once you become pregnant, your doctor will address gestational diabetes as part of your regular prenatal care. If you develop gestational diabetes, you may need more frequent checkups. These are most likely to occur during the last three months of pregnancy, when your doctor will carefully monitor your blood sugar level. In addition, your doctor may refer you to other health professionals who specialize in diabetes management, such as an endocrinologist, a registered dietitian or a diabetes educator. They can help you learn to manage your blood sugar level during your pregnancy.

To make sure that your blood sugar level has returned to normal after your baby is born, your blood sugar will be checked often right after delivery and again in six weeks. Once you've had gestational diabetes, it's a good idea to have your blood sugar level tested regularly. The frequency of blood sugar level tests will in part depend on your test results soon after you deliver your baby.

Researchers don't yet know exactly why some women develop gestational diabetes. To understand how gestational diabetes occurs, it can help to understand how glucose is normally processed in the body.

Insulin is a substance produced by your pancreas. After you eat, sugar molecules from food — called glucose — flow into your bloodstream. Insulin helps glucose move from your bloodstream into cells in your body where it can be used as energy.

During pregnancy, the placenta that surrounds your growing baby produces high levels of a variety of hormones. Almost all of them impair the action of insulin in the tissues, thereby raising blood sugar. Modest elevation of blood sugar after meals is normal during pregnancy.

As your baby grows, the placenta produces more and more insulin-interfering hormones. In gestational diabetes, the placental hormones provoke a rise in blood sugar to a level that can affect the growth and development of your baby. Gestational diabetes usually develops during the last half of pregnancy — rarely as early as the 20th week, but often not until later in the pregnancy.

Your doctor will likely evaluate your risk factors for gestational diabetes early on in your pregnancy. Most women will have a screening test for gestational diabetes sometime during the second trimester of pregnancy.

Routine screening for gestational diabetes
Screening for gestational diabetes is recommended for most women. Medical experts haven't established a single set of screening guidelines. Some question whether gestational diabetes screening is needed if you're younger than 25 and have no risk factors. Others say that screening all pregnant women — no matter their age — is the best way to catch all cases of gestational diabetes.

Your doctor will recommend a screening schedule based on your specific risk factors. For most women with average risk of gestational diabetes, a blood test known as a glucose challenge test is recommended between weeks 24 and 28 of pregnancy. If you're at a high risk of gestational diabetes, your doctor may test you earlier.

• Initial glucose challenge test. You'll begin the glucose challenge test by drinking a syrupy glucose solution. One hour later, you'll have a blood test to measure your blood sugar level. A blood sugar level below 130 to 140 milligrams per deciliter (mg/dL), or 7.2 to 7.8 millimoles per liter (mmol/L), is usually considered normal on a glucose challenge test, although this may vary at specific clinics or labs. If your blood sugar level is higher than normal, it only means you have a higher risk of gestational diabetes. Your doctor will diagnose you after giving you a follow-up test.
• Follow-up glucose challenge tests. For the follow-up tests, you'll be asked to fast overnight and then have your fasting blood sugar level measured. Then you'll drink another sweet solution — this one containing a higher concentration of glucose — and your blood sugar level will be checked every hour for a period of three hours. If at least two of the blood sugar readings are higher than normal, you'll be diagnosed with gestational diabetes.

If you're diagnosed with gestational diabetes
If you're diagnosed with gestational diabetes, your doctor will likely recommend frequent checkups, especially during the last three months of pregnancy. During these exams, your doctor will carefully monitor your blood sugar level. Your doctor may also ask you to monitor your own blood sugar daily, as part of your treatment plan.

If you're having trouble controlling your blood sugar level, you need insulin, or you have other pregnancy complications, you may need additional tests to assess your baby's general health. These tests are designed to assess the function of the placenta. This is because if your gestational diabetes is difficult to control, it may affect the placenta and endanger the exchange of oxygen and nutrients to the baby. One abnormal test result doesn't necessarily indicate a problem. Your doctor may do additional tests to more accurately assess how your baby is doing.

• Nonstress test. Sensors placed on your stomach are connected to a monitor. This test evaluates increases in fetal heart rate that are expected with fetal movement. If they're absent, the fetus may not be receiving enough oxygen.
• Biophysical profile (BPP). This test combines a nonstress test with a fetal ultrasound. Your doctor assesses your baby's movements, breathing and whether a normal amount of amniotic fluid is present. The components assessing fetal activity indicate the baby's oxygen status at the time the test is done. Decreased fluid means your baby hasn't been urinating enough and could indicate that over time the placenta has not been working as well as it should.
• Fetal movement counting. You may perform this simple test at the same time as the nonstress test or the biophysical profile. You simply count the number of times your baby kicks within a certain time frame. Less movement may mean your baby isn't getting enough oxygen.

Blood sugar testing after you give birth
To make sure that your blood sugar level has returned to normal after your baby is born, your doctor will check your blood sugar levels after delivery and again in six weeks. If your test results are normal, it's a good idea to have your diabetes risk assessed at least every three years. If your blood sugar levels indicate diabetes or prediabetes — a condition in which your blood sugar level is higher than normal, but not high enough to be classified as diabetes — talk with your doctor about starting a diabetes treatment plan.

Controlling your blood sugar level is essential to keeping your baby healthy and avoiding complications during delivery. Your treatment plan may include:

• Blood sugar monitoring. Your health care provider may ask you to check your blood sugar level four to five times a day — first thing in the morning and after meals — to make sure you're keeping your blood sugar within a healthy range. This may sound inconvenient and difficult, but it'll get easier with practice. To test your blood sugar, you draw a drop of blood from your finger using a small needle (lancet), then place the blood on a test strip inserted into a blood glucose meter — a device that measures and displays your blood sugar level.

  Your health care provider will also monitor your blood sugar level during labor. If your blood sugar rises, your baby may release high levels of insulin — which can lead to low blood sugar right after birth.

• Diet. Eating the right kind and amount of food is one of the best ways to control your blood sugar level. Making healthy food choices also helps prevent excessive weight gain during pregnancy, which can put you at higher risk of complications.

  A healthy diet often means including more fruits, vegetables and whole grains — foods that are high in nutrition and low in fat and calories — into your diet and limiting carbohydrates including sweets. Even so, no single diet is right for every woman. You might want to consult a registered dietitian or a diabetes educator to create a meal plan based on your blood sugar level, height, weight, exercise habits and food preferences.

• Exercise. Exercise lowers your blood sugar level by transporting sugar to your cells, where it's used for energy. Exercise also increases your sensitivity to insulin, which means your body needs less insulin to transport sugar to your cells. And there's more. Regular exercise can help prevent some of the discomforts of pregnancy, such as back pain, muscle cramps, swelling, constipation and difficulty sleeping. It can also help prepare you for labor and delivery.

  With your doctor's OK, aim for moderate aerobic exercise on most days of the week. If you haven't been active for a while, start slowly and build up gradually. Walking, cycling and swimming are often good choices during pregnancy. Ordinary activities such as housework and gardening also count.

• Medication. If diet and exercise aren't enough, you may need insulin injections to lower your blood sugar level. About 15 percent of women who have gestational diabetes need insulin therapy to reach a consistently safe blood glucose level. For some women, an oral medication, such as glyburide, also is an option.

Your baby will need close observation, too. Your doctor may monitor your baby's growth and development with repeated ultrasounds or other tests. If you don't go into labor by your due date — or sometimes earlier — your doctor may induce labor. Delivering your baby after your due date may increase the risk of complications.

After having gestational diabetes, your risk of developing type 2 diabetes later in life increases. Maintaining healthy lifestyle habits, such as a healthy diet and exercise, can help reduce or eliminate this risk.