Learn about Glucose Levels and Gestational Diabetes

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What is Gestational Diabetes?

Gestational diabetes is a type of diabetes that occurs in women when they are pregnant (in women who do not have pre-existing diabetes). Monitoring glucose levels and gestational diabetes symptoms is important. If untreated, serious problems can occur to both mom and baby. In the majority of women, the condition corrects itself after birth.

Causes and Risk Factors

Weight gain and changing hormones related to pregnancy affect insulin, a hormone that controls glucose levels. Risk factors include having a close family member with diabetes, being 25 years old or older, and being overweight or obese. African Americans and Hispanics are more likely to have than Caucasians.


Many women do not experience symptoms. However, the following can occur: excessive hunger/thirst, excessive weight gain, excessive urination, and recurrent vaginal infections.


Women who are at low risk may not need to be tested. Those at average risk may be tested during their 24th - 28th week of pregnancy. Women at high risk may be tested on their first prenatal visit.


The first test to be performed is normally a screening test called glucose challenge test (gct). The person will drink a sugary beverage containing 50 grams of glucose (this should be consumed within 5 minutes). One hour later, a blood sample will be drawn to check glucose levels. This test will show how efficiently the body processes sugar and can be done at any time of the day. If levels are high, a more accurate test will most likely be done to properly diagnose gestational diabetes.

Typically, if the glucose level is 130-140 mg/dL or higher, a glucose tolerance test (gtt) will be done. If the glucose level is more than 200 mg/dL, most health care providers will diagnose their patient with gestational diabetes without doing the gtt.


Three days before a glucose tolerance test, the person will be asked to consume at least 150 grams of carbohydrates each day. Eight to fourteen hours prior to the test, the person will be instructed to not eat or drink anything (except small amounts of water), smoke, or exercise. Because of this, the test is normally performed in the morning hours.

First, a blood sample will be drawn to determine a fasting glucose level. Afterwords, the person will drink a sugary beverage containing 100 grams of glucose. Then a blood sample will be drawn in 1 hour, 2 hours, and 3 hours to check glucose levels. The following are above-normal results according to the American Diabetes Association:

  • fasting 95 mg/dL or higher
  • 1 hour 180 mg/dL or higher
  • 2 hours 155 mg/dL or higher
  • 3 hours 140 mg/dL or higher.

If one of the above glucose levels is abnormal, the test may be repeated later in the pregnancy. If two or more are abnormal, the person will be diagnosed with gestational diabetes.


The treatment for gestational diabetes involves controlling blood glucose levels with diet, physical activity, and (if needed) insulin or medicine. The person will learn about glucose levels and gestational diabetes symptoms. She will learn how to use a meter, when to test, what levels are acceptable, what symptoms to be aware of, and how to give insulin if needed.

Normally, glucose levels are checked:

  • first thing in the morning (fasting)
  • right before meals
  • 1-2 hours after meals.

The following results are considered normal for most women with gestational diabetes:

  • fasting not above 95 mg/dL
  • 1 hour after a meal not above 140 mg/dL
  • 2 hours after a meal not above 120 mg/dL.

Although most women will no longer have problems with glucose levels after giving birth, they are at risk of having gestational diabetes with future pregnancies, and of developing type 2 diabetes later in life.

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