What is gestational diabetes?
Gestational diabetes, also known as gestational diabetes mellitus, GDM, or diabetes during pregnancy, is a type of diabetes that only pregnant women get. If a woman gets diabetes when she is pregnant, but never had it before, then she has gestational diabetes.
Normally, your stomach and intestines digest the carbohydrate in your food into a sugar called glucose. Glucose is your body's main source of energy. After digestion, the glucose moves into your blood to give your body energy.
To get the glucose out of your blood and into the cells of your body, your pancreas makes a hormone called insulin. If you have diabetes, either your body doesn't make enough insulin, or your cells can't use it the way they should. Instead, the glucose builds up in your blood, causing diabetes, or high blood sugar.
Gestational diabetes happens in about 5 percent of all pregnancies, or about 200,000 cases a year in the United States.
How do I know if I have gestational diabetes?
Health care providers will test most women who have average risk for gestational diabetes when they are between 24-28 weeks pregnant.
If your risk is higher-than-average, your health care provider may test you earlier, possibly as soon as you know you are pregnant.
There are two approaches to testing for gestational diabetes:
- In the one-step approach, a woman will fast for 4 to 8 hours. Then a health care provider will measure her blood sugar and will do so again 2 hours after she drinks a sugar drink. This type of test is called an oral glucose tolerance test.
- In the two-step approach, a health care provider measures a woman's blood sugar 1 hour after drinking a sugar drink. Women whose blood sugar is normal after 1 hour probably don't have gestational diabetes. Women whose blood sugar is high after 1 hour will then have an oral glucose tolerance test to see if they have gestational diabetes.
Will gestational diabetes affect the baby?
Most women who have gestational diabetes give birth to healthy babies, especially when they control their blood sugar, eat a healthy diet, exercise, and keep a healthy weight.
In some cases, though, gestational diabetes can affect the pregnancy and baby. Some potential risks include:
- The baby's body is larger than normal—called macrosomia. A large baby may need to be delivered by a surgical procedure called cesarean section, instead of naturally through the vagina.
- The baby's blood sugar is too low—called hypoglycemia. Starting to breastfeed right away can help get more glucose to the baby. The baby may also need to get glucose through a tube into his or her blood.
- The baby's skin turns yellowish and the whites of the eyes may change color—called jaundice. This condition is easily treated and is not serious if treated.
- The baby may have trouble breathing and need oxygen or other help—called Respiratory Distress Syndrome.
- The baby may have low mineral levels in the blood. This problem can causes muscle twitching or cramping, but can be treated by giving the baby extra minerals
How is gestational diabetes treated?
Many women with gestational diabetes have healthy pregnancies and healthy babies because they follow a treatment plan from their health care provider.
Each woman should have a specific plan designed just for her needs, but there are some general ways to stay healthy with gestational diabetes:
- Know your blood sugar and keep it under control – By testing how much sugar is in your blood, it is easier to keep it in a healthy range. Women usually need to test a drop of their blood several times a day to find out their blood sugar level.
- Eat a healthy diet – Your health care provider can make a plan with the best diet for you. Usually controlling carbohydrates is an important part of a healthy diet for women with gestational diabetes because carbohydrates affect blood sugar.
- Get regular, moderate physical activity – Exercise can help control blood sugar levels. Your health care provider can tell you the best activities and right amount for you.
- Keep a healthy weight – The amount of weight gain that is healthy for you will depend on how much you weighed before pregnancy. It is important to track your both your overall weight gain and weekly rate of gain.
- Keep daily records of your diet, physical activity, and glucose level – Women with gestational diabetes should write down their blood sugar numbers, physical activity, and everything they eat and drink in a daily record book. This can help track how well the treatment is working and what, if anything, needs to be changed.
Some women with gestational diabetes will also need to take insulin to help manage their diabetes. The extra insulin can help lower their blood sugar level. Some women might also have to test their urine to see if they are getting enough glucose.
What happens after the baby is born?
For most women, blood sugar levels go back to normal quickly after the baby is born. Six weeks after the baby is born, you should have a blood test to check your blood sugar levels. The test also checks for your risk of getting diabetes in the future.
If you know you want to get pregnant again, have a blood sugar test up to three months before becoming pregnant to make sure your blood sugar level is normal.
Children whose mothers had gestational diabetes are at higher risk for obesity, abnormal glucose tolerance, and diabetes.
Women who have had gestational diabetes and children whose mothers had gestational diabetes are at higher lifetime risk for obesity and type 2 diabetes. It may be possible to prevent type 2 diabetes through lifestyle changes. Talk to your health care provider about diabetes and increased risk from gestational diabetes.
Used with permission from NICHD publications