DIABETES AND ENDOCRINE SYSTEM Diabetes Complications • Peripheral neuropathy • Gestational diabetes • Type 1 diabetes • Diabetic retinopathy • Metabolic syndrome • Dehydration • Type 2 diabetes • Prediabetes • Diabetic coma • Diabetic hyperosmolar syndrome • Diabetic ketoacidosis DIABETES AND ENDOCRINE SYSTEM Endocrine System • Graves' disease • Hypoglycemia • Goiter • Male hypogonadism • Gestational diabetes • Type 1 diabetes • Hyperthyroidism • Hypothyroidism • Addison's disease • Hyperparathyroidism • Diabetic retinopathy • Cushing's syndrome • Acromegaly • Hypopituitarism • Thyroid nodules • Metabolic syndrome • Prolactinoma • Pituitary tumors • Dehydration • Primary aldosteronism • Hashimoto's disease • Pheochromocytoma • Type 2 diabetes • Prediabetes • Diabetic coma • Diabetic hyperosmolar syndrome • Diabetic ketoacidosis • Diabetes insipidus

Note: All links within content go to MayoClinic.com

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 blood sugar (glucose) — your body's main source of fuel. As a result, your blood sugar level is too high.

If untreated or uncontrolled, gestational diabetes can result in a variety of health problems for you and your baby.

If you have gestational diabetes, you and your doctor will devise a plan to keep your blood sugar levels within a normal range. The good news is that controlling your blood sugar can help ensure a healthy pregnancy for you and a healthy start for your baby.

Most women don't experience any signs or symptoms of gestational diabetes. When they do occur, signs and symptoms may include:

• Excessive thirst
• Increased urination

During digestion, your body breaks carbohydrates into simple sugar molecules that it can eventually use for energy. One of these sugar molecules is glucose, the main energy source for your body. 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. The insulin "escorts" sugar into your cells, providing your body with energy while maintaining a normal level of sugar in your blood.

Your liver also plays a key role in maintaining a normal blood sugar level. If you have more glucose than your cells need for energy, your body can remove that excess from your bloodstream and store it in your liver as glycogen. Then, when you run low on glucose — for example, if you haven't eaten for a while — your body can tap into that stored glucose and release it into your bloodstream.

The amount of glucose in your blood fluctuates in response to a number of factors, including the food you eat, exercise, stress and infections. Yet the complex relationship among insulin, glucose and your liver ensures that your blood sugar stays within set limits.

During pregnancy, your placenta — the organ that supplies your baby with nutrients through the umbilical cord — produces hormones that prevent insulin from doing its job. These hormones, which include estrogen, cortisol and human placental lactogen, are vital to preserving your pregnancy. Yet they also make your cells more resistant to insulin.

As your placenta grows larger in the second and third trimesters, it secretes even more of these hormones, further increasing insulin resistance. Normally, your pancreas responds by producing enough extra insulin to overcome this resistance. But you may need up to three times as much insulin as normal, and sometimes your pancreas simply 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. It usually occurs about the 20th to 24th week of pregnancy and can be measured by the 24th to 28th week of pregnancy. After your baby is born and placental hormones disappear from your bloodstream, your blood sugar levels should quickly return to normal.

Any woman can develop gestational diabetes, but some women are at greater risk than are others. These factors increase your risk:

• Age. Women older than age 25 are more likely to develop gestational diabetes.
• Family or personal history. Your chance of developing gestational diabetes increases if a close family member, such as a parent or sibling, has type 2 diabetes. You're also more likely to have gestational diabetes if you've had it in a previous pregnancy.
• Weight. Being overweight before pregnancy makes it more likely that you'll develop gestational diabetes. However, gaining weight during your pregnancy doesn't cause gestational diabetes.
• Race. For reasons that aren't clear, women of some races are more likely to develop gestational diabetes than are others. You're at increased risk if you're black, Hispanic or American Indian.
• Previous complicated pregnancy. If you've had an unexplained stillbirth or a baby who weighed more than 9 pounds, you may be screened more closely for gestational diabetes the next time you become pregnant.

Many women who develop gestational diabetes have no known risk factors.

Your health care provider will address gestational diabetes as part of your regular prenatal care. If you develop gestational diabetes, see your health care provider for regular checkups. How often you see your provider depends on the severity of your diabetes and whether you have any other complications. Office visits with your health care provider are especially important during the final three months of your pregnancy, when he or she will carefully monitor your blood sugar levels.

In addition, your health care provider may refer you to other health professionals who specialize in the management of diabetes, such as an endocrinologist, a registered dietitian or a diabetes educator. They can help you learn to manage your blood sugar 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 glucose level has returned to normal after your baby is born, you'll have your blood sugar checked often after delivery and again in six weeks. Once you've had gestational diabetes, continue to have your blood sugar tested at least once a year. And continue healthy lifestyle habits to lessen your chances of developing type 2 diabetes.

In some places, screening for gestational diabetes is a routine part of prenatal care for all women. Until recently, though, there was no scientific proof that screening resulted in fewer childbirth complications and healthier babies. In a 2005 study, researchers screened pregnant women for gestational diabetes and randomly assigned those with gestational diabetes to receive aggressive or routine treatment. The outcome — healthier babies and fewer childbirth complications for women who received aggressive treatment — demonstrated the wisdom of screening all mothers.

To screen for gestational diabetes, most doctors recommend a glucose challenge test. This test is usually done between 24 and 28 weeks of pregnancy, because the condition usually can't be detected until then. However, if your doctor thinks you're especially at risk, the test may be performed earlier.

If you're younger than 25 and have no other risk factors for gestational diabetes, there is some debate about whether you should undergo the test. Some doctors argue that younger women don't need this test. Others say that screening all pregnant women — no matter their age — is the best way to catch all cases of the disease.

What to expect from the test
When you arrive for a glucose challenge test, you'll be asked to drink a glucose solution that tastes like extra-sweet soda pop. Then you're in for a one-hour wait, before a blood sample is drawn from a vein in your arm to determine your blood sugar level. The glucose drink may make you feel nauseous or dizzy. But the syrupy solution — and the wait — are necessary to tell how efficiently your body processes sugar.

A blood sugar level below 140 milligrams per deciliter (mg/dL) is usually considered normal on a glucose challenge test. Having a blood sugar level above 140 mg/dL doesn't necessarily mean you have gestational diabetes. To confirm the diagnosis, you'll need a second test.

For the follow-up test, you'll be asked to fast overnight. You're then given another sweet solution to drink — this one containing a higher concentration of glucose — and your blood sugar levels are checked every hour for a period of three hours. Having at least two instances of abnormally high blood sugar levels confirms the diagnosis of gestational diabetes.

Why these tests?
Some women wonder why it's necessary to undergo these screening tests in addition to routine urine samples. A urine sample isn't a reliable indicator of gestational diabetes because the amount of sugar in your urine can vary throughout the day and as a result of what you eat. Screening tests are a much better way to identify women with gestational diabetes.

Some women worry that having gestational diabetes will cause birth defects. Fortunately, this usually isn't the case. In general, birth defects originate during the first three months of pregnancy, while gestational diabetes generally doesn't develop until the second or third trimester. This means your blood sugar levels are normal during the first critical months.

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

Complications that may affect your baby
Consistently keeping your blood sugar levels within a normal range can reduce these possible complications:

• Macrosomia. Extra glucose can cross the placenta and end up in your baby's blood. When that happens, your baby's pancreas makes extra insulin to process the extra glucose, and this can cause your baby to grow too large (macrosomia). For a full-term pregnancy, this means a birth weight of 4,500 grams (9 pounds, 14 ounces) or more. Very large babies may have difficulty during delivery and are more likely to sustain birth injuries or be born by Caesarean delivery.
• Shoulder dystocia. If you have a very large baby, your baby's shoulders may be too big to move through the birth canal. This results in a potentially life-threatening obstetrical emergency, known as shoulder dystocia. In most cases, doctors can perform maneuvers to free the baby, but injuries may occur under the best of care. This is a rare but very serious complication of gestational diabetes.
• Hypoglycemia. Sometimes babies of mothers with gestational diabetes develop low blood sugar (hypoglycemia) shortly after birth. That's because they're accustomed to receiving large amounts of blood sugar from their mothers, and their own insulin production is high. These infants should have their blood sugar levels checked regularly after delivery. Treating this problem involves feeding right away. Your baby may even need a glucose solution through an intravenous line to prevent low blood sugar.
• Respiratory distress syndrome. Babies born prematurely to mothers with gestational diabetes are more likely to develop respiratory distress syndrome, a condition that makes breathing difficult. It's caused by a lack of certain substances in the lungs that help prevent the lungs from collapsing every time the baby takes a breath. Babies with 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 is another potential complication. Newborn jaundice may begin during the second or third day of life, but sometimes isn't evident until around a week after birth. Jaundice itself isn't a disease. In most cases it occurs because 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, it should be carefully monitored by your doctor.
• Stillbirth or death. If gestational diabetes goes undetected, a baby has an increased risk of stillbirth or death as a newborn.

Complications that may affect you
If you have gestational diabetes, you may be at risk of these complications:

• Preeclampsia. This condition is primarily characterized by a significant increase in blood pressure. Left untreated, it can lead to serious, even deadly complications for the mother and fetus. Having gestational diabetes puts you at higher risk of developing this condition, so you'll want to discuss it with your doctor.
• Operative delivery. Gestational diabetes isn't a reason to schedule a Caesarean delivery. But your doctor may recommend one if your baby has macrosomia.
• Gestational diabetes in another pregnancy. Once you've had gestational diabetes in one pregnancy, you're more likely to have it again with the next pregnancy.
• Type 2 diabetes. Women who have gestational diabetes are more likely to develop type 2 diabetes — a type of diabetes that's present all the time, not just during pregnancy — as they get older. Many cases of diabetes can be prevented with a healthy diet and regular exercise.

Controlling your blood sugar is essential to keeping your baby healthy and avoiding complications during delivery. Most women with gestational diabetes are able to control their blood sugar with diet and exercise, but some may need medication in addition to lifestyle changes. In either case, monitoring your blood sugar is a key part of your treatment program because it tells you whether your blood sugar is staying within a normal range.

The most recent data support aggressively treating all pregnant women with gestational diabetes. Evidence favoring aggressive treatment comes from the same 2005 study that proved the benefit of screening all pregnant women for gestational diabetes. Researchers compared pregnancy outcomes in two groups of women with gestational diabetes. One group received aggressive treatment — dietary advice, frequent blood glucose monitoring and insulin injections for elevated blood glucose levels. Another goal of aggressive treatment was to maintain tight control of blood glucose. The blood glucose goals for this group were 63 to 99 milligrams of glucose per deciliter (mg/dL) for fasting blood sugar and 126 mg/dL or lower two hours after meals. The other group received routine care, which may or may not have included insulin.

The women who received aggressive treatment and maintained tighter glucose control developed significantly fewer childbirth problems than did the women who had routine care. Aggressive treatment was particularly effective in reducing the types of problems caused by having unusually large babies, as women with high blood glucose during pregnancy often do.

In addition, the group that received aggressive treatment reported lower rates of depression and scored higher on health-related quality of life three months after giving birth than did the group receiving routine care. It isn't clear, however, why these particular benefits occurred.

Monitoring your blood sugar
If you've just learned that you have diabetes, monitoring your blood sugar may sound inconvenient and difficult. But once you learn how it's done, you'll likely grow more comfortable with the procedure.

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 small, computerized device that measures and displays your blood sugar level.

Your blood sugar fluctuates throughout the day. What and how much you eat and even the time of day also can have an effect. For that reason, your doctor may ask you to check your blood sugar four to five times a day. Your goal is to make sure you're keeping your blood sugar levels within a healthy range.

Your doctor will also monitor your blood sugar during labor. If your blood sugar levels rise, your baby's blood sugar will rise, too. This can cause your baby to have high levels of insulin, which may lead to low blood sugar right after birth.

Eating a healthy diet
A healthy diet is important for every pregnant woman, but it's even more important if you have gestational diabetes. Eating the right kind and amount of food is one of the best ways to control your blood sugar levels.

In general, you'll need 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 one diet is right for every woman. If you have gestational diabetes, work with a registered dietitian or counselor who can help you put together an individual meal plan based on your blood sugar level, height, weight, exercise habits and food preferences.

Getting regular exercise
In general, the more active you are, the lower your blood sugar. Physical activity causes sugar to be transported to your cells where it's used for energy, lowering the levels in your blood. Exercise also reduces blood sugar by increasing your sensitivity to insulin: Your body requires less insulin to transport glucose into your cells.

In addition, 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. The increased muscle strength and endurance you develop reduce stress on your ligaments and joints during delivery, help you during labor, and shorten your recovery time.

Your doctor will discuss exercise as a part of the treatment for gestational diabetes. Once you understand the ground rules, take some time to think about which activities you enjoy. Walking, cycling and swimming are good ways to get a safe aerobic workout. Ordinary activities such as housework and gardening also can lower your blood sugar.

Aim for moderate aerobic exercise on most days. If you haven't been active for a while, start slowly and build up gradually. For best results, combine aerobic activity with stretching and strength-training exercises. Exercising at the same time every day, varying your fitness routine and working out with other pregnant women can help you stay motivated.

Taking medications
Sometimes diet and exercise may not be enough. In that case, you may need to take daily medication to help lower your blood sugar to safe levels.

Until recently, insulin was the only option for women with gestational diabetes because it doesn't cross the placental barrier. But the oral anti-diabetes drug, glyburide, also may be safe and effective in controlling blood sugar in gestational diabetes. Doctors in Europe use metformin to treat gestational diabetes, and this medication is being studied in the United States.

Monitoring your baby
Your obstetrician will likely recommend close monitoring of your baby's growth — usually using ultrasound. This test combines high-frequency sound waves and computer processing to generate pictures of the inside of your uterus. Although ultrasound can give a good idea of your baby's size, it tends to be less accurate as your baby gets bigger.

If you need medications to control your gestational diabetes, your obstetrician may also recommend a nonstress test (NST) or biophysical profile to make sure your baby is getting enough oxygen and nourishment, especially as you approach your due date. A nonstress test is just that — a noninvasive test that causes no stress to your baby. In fact, it shouldn't be stressful for you either. NST usually takes less than 30 minutes and requires no hospitalization. It's a simple procedure that checks how often your baby moves and how much his or her heart rate increases with movement. A biophysical profile combines an ultrasound with NST to provide more information about your baby's breathing, tone, movement and the volume of amniotic fluid in your uterus.

In most cases, your doctor will try to prevent your pregnancy from going longer than 40 weeks because being overdue may increase the risk of complications. Although most women with gestational diabetes deliver happy, healthy babies, labor with gestational diabetes isn't routine, and Caesarean delivery is necessary in some cases. However, gestational diabetes doesn't affect your ability to breast-feed or care for your new baby.

It's not easy to live with a condition that can affect the health of your unborn child. Although most of the complications of gestational diabetes can be prevented with diet and exercise, it can be stressful to regularly monitor your blood sugar and follow a specific diet and exercise plan.

Besides, worrying about your baby can make it harder to take care of yourself and manage your condition. You may actually find yourself eating all of the wrong foods or forgetting to exercise. Prolonged stress can even cause your blood sugar levels to rise.

You'll probably feel better if you learn as much as you can about your condition. In addition to talking to your doctor and a diabetes educator or dietitian, look for information in books or on the Internet. Ask your doctor to put you in touch with other women who have the same disorder.

And remember: The very steps you're taking to control your blood sugar — such as eating a healthy diet and getting regular exercise — can help relieve stress and nourish your baby. These activities may also help prevent you from developing type 2 diabetes in the future. That makes exercise and good nutrition your most powerful tools for a healthy life as well as for a healthy pregnancy.