Gestational diabetes affects between 4 percent and 7 percent of pregnant women in the U.S. If you have gestational diabetes, you can still give birth to a healthy baby. Learn more.

What is gestational diabetes?
Gestational diabetes is high blood sugar that starts during pregnancy. It usually appears around the 24th week of pregnancy.

Diabetes occurs when your body doesn't have enough insulin or can't use insulin properly. Insulin is a hormone made by the pancreas. When you eat, your body breaks food down to glucose (sugar). The glucose enters your bloodstream. Insulin moves glucose from the bloodstream to the cells, which the cells use for energy. Glucose stays in the bloodstream if you don't have enough insulin. This is why people with diabetes have "high blood sugar" levels.

During pregnancy, hormones from the placenta may block insulin from working properly in the mother's body. This may cause gestational diabetes. Although diabetes usually goes away after the baby is born, it can increase your risk of developing diabetes later in life.

What are the symptoms?
Gestational diabetes often has no symptoms. Doctors routinely test all women for diabetes between the 24th and 28th weeks of pregnancy. If you're at high risk, you may be tested earlier. High risk factors include:

• Obesity
• Gestational diabetes with a previous pregnancy or delivery of large-for-gestational-age infant
• Glucose in the urine (glycosuria)
• Polycystic ovarian syndrome (PCOS)
• Strong family history of type 2 diabetes

Who gets gestational diabetes?
While any pregnant woman can get gestational diabetes, it's more common in women who:

• Are overweight or obese
• Have high blood pressure or high cholesterol
• Don't get enough exercise
• Have a family history of diabetes
• Have heart and blood vessel disease or a family history of it
• Have polycystic ovarian syndrome
• Are of Native American, African American, Asian, Hispanic or Pacific Islander descent

How is it diagnosed?
Doctors test for gestational diabetes using an oral glucose tolerance test (OGTT). For this test, you'll fast for about 8 hours and then have your blood drawn so your doctor can get a fasting blood sugar level. Then you drink a special sugary drink. Another blood sample is taken and blood sugar is measured again at certain times after the drink. If you have two or more of the following blood sugar readings, you may have gestational diabetes:

• 95 mg/dL or more after fasting
• 180 mg/ dL or more after 1 hour
• 155 mg/dL or more after 2 hours
• 140 mg/dL or more after 3 hours

How is it managed?
The goal of managing gestational diabetes is to keep your blood glucose levels under control. You may need to check your blood sugar level several times a day using a blood glucose meter. Ask your doctor what your target blood sugar levels should be. Often, gestational diabetes can be controlled with diet and exercise. Sometimes insulin or an oral medication is needed.

• Nutrition. Work with your doctor and a dietician to design a nutrition plan. They may suggest a diet rich in fruits, vegetables, whole grains, lean meats and nonfat dairy, and low in fat, sodium and cholesterol. Your doctor may adjust your diet throughout your pregnancy to better control your blood sugar and meet the needs of your growing baby.
• Exercise. Exercise can lead to better blood sugar control and more energy. First, check with your doctor to see what activity level is safe and healthy for you and your baby.
• Insulin or oral medicine. Some pregnant women may need to take insulin shots or oral medicine to control blood sugar. Your doctor will let you know what treatment is best for you.
• Prenatal care. Your doctor will monitor your diabetes throughout your pregnancy. You may need to have certain blood tests done more often because of the diabetes.

Effects during pregnancy
Gestational diabetes is more likely to cause problems for you and your baby if your blood sugar levels are not under control .This is why it's important to follow your treatment plan closely. Effects on you and your baby include:

• Preeclampsia. This condition causes high blood pressure and protein in the urine. It's dangerous for both the mother and baby. The baby may have to be delivered early. If not treated, it can lead to an even more serious condition called eclampsia.
• Too much amniotic fluid (polyhydramnios). Gestational diabetes can cause too much amniotic fluid to build up in the sac that surrounds the baby. The mother may be uncomfortable and the baby may have to be delivered early.
• Urinary tract infections. These infections may have no symptoms.The infection could spread to the kidneys if left untreated.
• Macrosomia (very large baby). When the mother's blood sugar levels are high throughout pregnancy it can result in a large baby. The birth may be difficult because the baby is so large.
• Cesarean birth (c-section). Larger babies or other diabetes related problems can require cesarean birth. Recovery from a c-section may be longer and harder than recovery from a vaginal birth.
• Breathing problems in the newborn.
• Stillbirth.

Related Articles Diabetes, Pregnancy and Exercise Gestational Diabetes: What Happens After the Baby is Born? Who Is Most at Risk for Developing Gestational Diabetes? How Will Gestational Diabetes Affect My Labor and Delivery? Treatment for Gestational Diabetes Large Babies Pose Risks and Complications for Both Mother and Baby Diabetes During Pregnancy: Long-Term Health Risks for Large Babies Mom's Weight Can Be Big Risk for Baby

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This article was reviewed and updated 08-01-2009.