What is Fasting Glucose?
Fasting glucose is a blood test that requires the patient skip food for at least 12 hours prior to the test. Typically, the test is administered first thing in the morning so the patient can stop about bedtime for the test the following morning. When the body has no food to digest, the pancreas responds by releasing glucagon. Insulin is then released to control the glucagon thus regulating blood glucose levels. If the body does not react properly to the glucagon or if the insulin is not utilized properly, fasting blood glucose levels will stay high. High fasting blood glucose is one sign of diabetes.

One poor test result is not enough to verify a diabetes diagnosis. A second fasting glucose test will be ordered. If that result is also high, and there are no other factors in play that could affect blood glucose response, the patient is diagnosed with diabetes and treatment protocols discussed.

Normal Value Range

• Negative Pregnancy Adult: 75 to 99 mg/dL or 4.2 to 5.5 mmol/L
• Pregnancy Trimester One: -mg/dL or –mmol/L
• Pregnancy Trimester Two: 75 to 80 mg/dL or 4.2 to 4.4 mmol/L
• Pregnancy Trimester Three: 71 to 77 mg/dL or 4 to 4.3 mmol/L

When fasting glucose numbers are higher than 92 mg/dL or 5.1 mmol/L and lower than 126 mg/dL or 7 mmol/L a pregnant woman may have gestational diabetes.

Values higher than 126 mg/dL or 7 mmol/L are indicative of diabetes regardless of pregnancy.

< Laboratory Values During Pregnancy