THREE-HOUR GLUCOSE TEST

Whenever a 3-hour glucose test is performed, it is needed to establish the diagnosis of diabetes. There are special instructions to follow in preparation for the test. For three days before the test diet of the pregnant mother should consist of 150 grams of carbohydrates each day. For example this can be accomplished by consuming one cup of pasta, two servings of fruit, four slices of bread, and three glasses of milk every day. The pregnant mother should not eat or drink anything but water 10-14 hours before the test. This test is usually preformed in the morning and usually in a laboratory.

The first step involves drawing a blood sample to measure the fasting blood sugar level of the patient. The patient will then be asked to drink 100 grams of a glucose drink. This glucose drink is often very sweet and may make some people feel nauseated. The final steps include drawing blood samples every hour for three hours after drinking the glucose solution. The following table shows the normal values for the three-hour glucose test.

Diagnostic Criteria

Normal Mean Values

 

Blood Glucose Level

Blood Glucose Level

Fasting

105 mg/dl

80 mg/dl

1 hour

190 mg/dl

120 mg/dl

2 hour

165 mg/dl

108 mg/dl

3 hour

145 mg/dl

90 mg/dl

These numbers represent the normal fasting blood sugar levels compared to the blood sugar levels after consuming the glucose drink every hour for three hours. The diagnostic criteria shows the blood sugar levels every hour for three hours after drinking the glucose solution. The normal mean values shows the blood sugar levels every hour for three hours without consuming the glucose drink.

If two or more of the patient's blood sugar levels are higher than the diagnostic criteria, the patient is then diagnosed with gestational diabetes.

 

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