Gestational diabetes occurs during pregnancy due to hormonal changes that render cells less responsive to insulin. Approximately 2 to 5 percent of pregnant women develop this condition. The condition rarely produces any obvious symptoms and so blood sugar testing is the only way to identify affected women.
Risk Factors
If you've had gestational diabetes in a past pregnancy, you are at a higher risk of developing the condition again. Obese women and those with a strong family history of diabetes have an elevated risk. Also, if your urine tests high for the presence of sugar, you may be at a higher risk. If you already have diabetes, your doctor will work with you to plan a healthy diet.
Glucose Challenge Test
Your health care provider will probably conduct a glucose challenge screening test when you are approximately 24 to 28 weeks pregnant. You will consume a beverage containing 50g of glucose within 5 minutes. One hour later, your blood will be drawn to determine how well your body processed the sugar. During this hour you will not be allowed to consume other foods. If your initial glucose challenge screen shows blood sugar levels that are elevated more than 140mg of glucose per deciliter of blood plasma, you will be asked to return for the glucose tolerance test. Some doctors recommend further monitoring for results greater than 130mg of glucose per deciliter.
Glucose Tolerance Test
In the second phase of testing, you will be asked to fast for 14 hours prior to consuming a high glucose drink. It's best to schedule this test for the early morning. Your blood will be drawn before you drink the glucose beverage and each hour afterwards for three hours. If more than two of these readings is abnormal, you will be diagnosed with gestational diabetes. The American Diabetes Association considers an abnormal reading to be greater than 95mg per deciliter after fasting, 180mg per deciliter after one hour, 155mg per deciliter after two hours and 140mg per deciliter after three hours.
Side Effects and Alternatives
Many women find that the high glucose beverage causes nausea, dizziness and in some cases, vomiting. If you have a history of these side effects, inform your doctor. Vomiting will render your test results uninterpretable. Some doctors will administer an alternative glucose source such as jellybeans.
