Note: This article
is the second in a series on gestational diabetes, published by STHS's Diabetes Education program in recognition of
November as National Diabetes Month. Scroll down to the bottom of this article for links to other articles in this series.
Getting tested for gestational diabetes, or GDM, is an important part of prenatal care. All pregnant women should be tested at least once during pregnancy. Your OB/GYN will consider your risk factors to determine when you should have this test and how often you should have it.
The American College of Obstetricians and Gynecologists recommends testing for gestational diabetes in low-risk pregnant women between 24 and 28 weeks of pregnancy. Your doctor may recommend an earlier screening if you’re at increased risk of developing gestational diabetes.
Risk factors may include:
- Gestational Diabetes in an earlier pregnancy.
- Family history of diabetes.
- Obesity.
- Having a medical condition associated with the development of diabetes, such as metabolic syndrome or polycystic ovary syndrome.
One way to screen for gestational diabetes is a glucose tolerance test, also known as the oral glucose tolerance test or GTT, which measures your body's response to sugar (glucose). The GTT is done in several steps.
Fasting blood sugar: Your blood glucose will be tested at arrival after an eight-hour fast.
One-hour glucose tolerance test: You drink a special beverage high in sugar. One hour later, your blood glucose levels are measured.
Three-hour glucose tolerance test: If the one-hour test is abnormal, a second glucose tolerance test will be conducted to confirm the diagnosis. You will drink another special beverage with additional sugar. Your blood glucose levels are checked one hour, two hours and three hours later.
Your doctor will consider the results of each blood glucose test. Key data include:
A normal fasting blood glucose level is lower than 95 mg/dL
- One hour after drinking the glucose solution, a normal blood glucose level is lower than 180 mg/dL
- Two hours after drinking the glucose solution, a normal blood glucose level is lower than 155 mg/dL
- Three hours after drinking the glucose solution, a normal blood glucose level is lower than 140 mg/dL
If one of the results is higher than normal, you'll likely need to test again in four weeks. If two or more of the results are higher than normal, you will be diagnosed with gestational diabetes.
If you are diagnosed with gestational diabetes, you can prevent complications by carefully managing your blood glucose level throughout the rest of your pregnancy. It is recommended that women with gestational diabetes check their blood glucose four times a day (fasting and 1 to 2 hours after each meal). Recommended blood glucose levels during pregnancy are as follows:
- Fasting: 95 mg/dl or less
- One hour after a meal: 140 mg/dl or less
- Two hours after a meal: 120 mg/dl or less
Other ways to manage gestational diabetes include:
Nutrition: Follow a healthy eating plan created by your doctor or dietitian that balances carbohydrates, protein and fats.
Being active: Regular physical activity that is moderately intense (such as brisk walking) lowers your blood glucose. Make sure to check with your doctor about what kind of physical activity you can do and if there are any kinds you should avoid.
Monitoring your baby: Your doctor will check your baby’s growth and development. If you develop gestational diabetes, you may need checkups more often. These are most likely to occur during the last three months of pregnancy, when your healthcare provider will monitor your blood glucose level and your baby's health.
Additional support: If healthy eating and being active aren’t enough to manage your blood glucose, your doctor may prescribe insulin or other medications to provide additional support in properly managing gestational diabetes.