Gestational diabetes

Definition

Gestational diabetes is high blood sugar (diabetes) that starts or is first diagnosed during pregnancy.

Alternative Names

Glucose intolerance during pregnancy

Causes, incidence, and risk factors

Risk factors for gestational diabetes include:

• African or Hispanic ancestry
• Being older than 25 when pregnant
• Family history of diabetes
• Giving birth to a previous baby that weighed more than 9 pounds
• Obesity
• Recurrent infections
• Unexplained miscarriage or death of a newborn

Symptoms

Usually there are no symptoms, or the symptoms are mild and not life threatening to the pregnant woman. Often, the blood sugar (glucose) level returns to normal after delivery.

Symptoms may include:

• Blurred vision
• Fatigue
• Frequent infections, including those of the bladder, vagina, and skin
• Increased thirst
• Increased urination
• Nausea and vomiting
• Weight loss in spite of increased appetite

Signs and tests

Gestational diabetes may not cause symptoms. All pregnant women should receive an oral glucose tolerance test between the 24th and 28th week of pregnancy to screen for the condition.

Treatment

The goals of treatment are to keep blood sugar (glucose) levels within normal limits during the pregnancy, and to make sure that the fetus is healthy.

WATCHING YOUR BABY

Your health care provider should closely check both you and your fetus throughout the pregnancy. Fetal monitoring to check the size and health of the fetus often includes ultrasound and nonstress tests.

• A nonstress test is a very simple, painless test for you and your baby. A machine that hears and displays your baby's heartbeat (electronic fetal monitor) is placed on your abdomen. When the baby moves, its heart rate normally increases 15 - 20 beats above its regular rate.
• Your health care provider can look at the pattern of your baby's heartbeat compared to its movements and find out whether the baby is doing well. The health care provider will look for increases in the baby's normal heart rate, occurring within a certain period of time.

DIET AND EXERCISE

Managing your diet can give you the calories and nutrients you need for your pregnancy, control your blood sugar (glucose) levels, and avoid the need to take medications. Regular exercise also can help keep your blood sugar under better control.

Eating a balanced diet is a key part of any pregnancy. The food you eat helps your baby grow and develop inside of you. Because every pregnancy is different, your doctor and dietitian will create a diet just for you.

• The best way to improve your diet is by eating a variety of healthy foods. Your doctor or nurse will prescribe a daily prenatal vitamin. They may suggest that you take extra iron or calcium. Talk to your doctor or nurse if you're a vegetarian or are on some other special diet.
• Remember that "eating for two" does not mean you need to eat twice as many calories. You usually need just 300 extra calories a day (such as a glass of milk, a banana, and 10 crackers).

For details on what you should eat, see: Diabetes diet

If managing your diet does not control blood sugar (glucose) levels, you may be prescribed diabetes medicine by mouth or insulin therapy. You will need to monitor your blood sugar (glucose) levels during treatment.

Expectations (prognosis)

Pregnant women with gestational diabetes tend to have larger babies at birth. This can increase the chance of problems at the time of delivery, including:

• Birth injury (trauma) because of the baby's large size
• Delivery by c-section

Your baby is more likely to have periods of low blood sugar (hypoglycemia) during the first few days of life.

Mothers with gestational diabetes have an increased risk for high blood pressure during pregnancy.

There is a slightly increased risk of the baby dying when the mother has untreated gestational diabetes. Controlling blood sugar levels reduces this risk.

High blood sugar (glucose) levels often go back to normal after delivery. However, women with gestational diabetes should be watched closely after giving birth and at regular doctor's appointments to screen for signs of diabetes. Many women with gestational diabetes develop diabetes within 5 - 10 years after delivery. The risk may be increased in obese women.

Complications

• Delivery-related complications due to the infant's large size
• Development of diabetes later in life
• Increased risk of newborn death
• Low blood sugar (glucose) or illness in the newborn

Calling your health care provider

Call your health care provider if you are pregnant and you have symptoms of diabetes.

Prevention

Beginning prenatal care early and regular prenatal visits helps improve the health of you and your baby. Knowing the risk factors for gestational diabetes and having prenatal screening at 24 - 28 weeks into the pregnancy will help detect gestational diabetes early.

References

Screening for gestational diabetes mellitus: Recommendation statement. Rockville, MD. US Preventive Services Task Force. Ann Intern Med. 2008; 148:759-765.

ACOG Practice Bulletin. Clinical management guidelines for obstetrician-gynecologists. Gestational Diabetes. Obstet Gynecol. 2001;98:525-38.

Landon MB, Catalano PM, Gabbe SG. Diabetes mellitus complicating pregnancy. In: Gabbe SG, Niebyl JR, Simpson JL, eds. Obstetrics - Normal and Problem Pregnancies. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2007:chap 37.

Cunnigham FG, Leveno KL, Bloom SL, et al . Antepartum assessment. In: Cunnigham FG, Leveno KL, Bloom SL, et al, eds. Williams Obstetrics. 22nd ed. New York, NY; McGraw-Hill; 2005:chap 15.

Cunnigham FG, Leveno KL, Bloom SL, et al . Diabetes. In: Cunnigham FG, Leveno KL, Bloom SL, et al, eds. Williams Obstetrics. 22nd ed. New York, NY; McGraw-Hill; 2005:chap 52.