Gestational diabetes

Definition

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. The result may be dangerously high blood sugar levels.

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.

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

Symptoms

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

Causes

During digestion, your body breaks down carbohydrates from foods such as bread, pasta, vegetables, fruits and dairy products into various sugar molecules. One of these sugar molecules is glucose, a main source of energy. Glucose is absorbed directly into your bloodstream after you eat, but it can't enter your cells without the help of insulin.

Your pancreas — a gland located just behind your stomach — produces insulin continuously. When your blood sugar increases after eating, insulin production also increases. The extra insulin "unlocks" your cells to more sugar, which provides your body with energy and helps maintain a normal level of sugar in your blood.

During pregnancy, the placenta produces hormones to sustain your pregnancy. These hormones make your cells more resistant to insulin. As your placenta grows larger in the second and third trimesters, it secretes more of these hormones — making it even harder for insulin to do its job.

Normally, your pancreas responds by producing enough extra insulin to overcome this resistance. But sometimes your pancreas can't keep up. When this happens, too little glucose gets into your cells and too much stays in your blood. This is gestational diabetes.

Gestational diabetes usually develops during the second trimester — sometimes as early as the 20th week, but often not until later in the pregnancy.

Risk factors

Any woman can develop gestational diabetes, but some women are at greater risk than are others. Risk factors for gestational diabetes include:

• Age. Women older than age 25 are more likely to develop gestational diabetes.
• Family or personal history. Your risk of developing gestational diabetes increases if you have prediabetes — a precursor to type 2 diabetes — or a close family member, such as a parent or sibling, has type 2 diabetes. You're also more likely to develop gestational diabetes if you had it during a previous pregnancy, if you delivered a baby who weighed more than 9 pounds, or if you had an unexplained stillbirth.
• Weight. You're more likely to develop gestational diabetes if you're overweight before pregnancy.
• Race. For reasons that aren't clear, women who are black, Hispanic, American Indian or Asian are more likely to develop gestational diabetes than are other women.

When to seek medical advice

Your health care provider will address gestational diabetes as part of your regular prenatal care. If you develop gestational diabetes, you may need more frequent checkups. Checkups are especially important during the last three months of pregnancy, when your health care provider will carefully monitor your blood sugar level.

In addition, your health care provider 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. In some cases, your health care provider may refer you to — or consult with — a doctor who specializes in high-risk pregnancies.

To make sure that your blood sugar level has returned to normal after your baby is born, your blood sugar will be checked often 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 at least once a year.

Tests and diagnosis

Screening for gestational diabetes is a routine part of prenatal care. Most health care providers recommend a blood test known as a glucose challenge test between 24 and 28 weeks of pregnancy — or earlier if you're at particularly high risk of gestational diabetes.

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) 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 your clinic's threshold, you'll likely need a second test to confirm the diagnosis.

For the follow-up test, you'll be asked to fast overnight. 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 age 25 or younger and have no risk factors for gestational diabetes, there's some debate about whether gestational diabetes screening is needed. Some health care providers argue that younger women don't need the test. Others say that screening all pregnant women — no matter their age — is the best way to catch all cases of gestational diabetes.

Complications

Most women who have gestational diabetes deliver healthy babies. However, untreated or uncontrolled blood sugar levels can cause problems for you and your baby.

Complications that may affect your baby
Gestational diabetes increases the risk of:

• Excess growth. Extra glucose can cross the placenta, which triggers your baby's pancreas to make extra insulin. This can cause your baby to grow too large (macrosomia). Very large babies are more likely to become wedged in the birth canal, sustain birth injuries or require a C-section birth.
• Low blood sugar. Sometimes babies of mothers with gestational diabetes develop low blood sugar (hypoglycemia) shortly after birth because their own insulin production is high. Prompt feedings and sometimes an intravenous glucose solution can return the baby's blood sugar level to normal.
• Respiratory distress syndrome. If your baby is delivered early, respiratory distress syndrome — a condition that makes breathing difficult — is possible. Babies who have respiratory distress syndrome may need help breathing until their lungs become stronger.
• Jaundice. This yellowish discoloration of the skin and the whites of the eyes may occur if a baby's liver isn't mature enough to break down a substance called bilirubin, which normally forms when the body recycles old or damaged red blood cells. Although jaundice usually isn't a cause for concern, careful monitoring is important.
• Type 2 diabetes later in life. Babies of mothers who have gestational diabetes have a higher risk of developing obesity and type 2 diabetes later in life.

Rarely, untreated gestational diabetes results in a baby's death either before or shortly after birth.

Complications that may affect you
Gestational diabetes increases the risk of preeclampsia, a condition characterized by high blood pressure and excess protein in the urine after the 20th week of pregnancy. Left untreated, preeclampsia can lead to serious or even life-threatening complications for both mother and baby.

Once you've had gestational diabetes in one pregnancy, you're more likely to have it again with the next pregnancy. You're also more likely to develop diabetes — typically type 2 diabetes — as you get older.

Treatments and drugs

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 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. This often means more fruits, vegetables and whole grains — foods that are high in nutrition and low in fat and calories — and fewer animal products and 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 health care provider'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. For some women, the oral medication glyburide may be an option as well.

Your baby will need close observation, too. Your health care provider 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 health care provider may induce labor. Delivering your baby after your due date may increase the risk of complications.

Prevention

There are no guarantees when it comes to preventing gestational diabetes — but the more healthy habits you can adopt before pregnancy, the better.

• Eat healthy foods. Choose foods low in fat and calories. Focus on fruits, vegetables and whole grains. Strive for variety to help you achieve your goals without compromising taste or nutrition.
• Get more physical activity. Aim for 30 minutes of moderate physical activity a day. Take a brisk daily walk. Ride your bike. Swim laps. If you can't fit in a long workout, break it up into smaller sessions spread throughout the day.
• Lose excess pounds. Weight loss during pregnancy isn't usually recommended. But if you're planning ahead, losing weight may help you have a healthier pregnancy. Focus on permanent changes to your eating and exercise habits. Motivate yourself by remembering the benefits of losing weight, such as a healthier heart, more energy and improved self-esteem.

Coping and support

It's not easy to live with a condition that can affect your baby's health. And worrying about your baby can make it harder to take care of yourself. You may find yourself eating the wrong foods or forgetting to exercise. Prolonged stress can even cause your blood sugar level to rise.

You'll probably feel better if you learn as much as you can about gestational diabetes. Talk to your health care provider. Read books and articles about gestational diabetes. Join a support group for women who have gestational diabetes. The more you know, the more control you'll feel.

Above all, remember that the very steps that will help control your blood sugar level — such as eating healthy foods and exercising regularly — can help relieve stress and nourish your baby. These activities can also help prevent type 2 diabetes in the future. That makes exercise and good nutrition powerful tools for a healthy pregnancy as well as a healthy life.