Also called the gestational diabetes test, glucose screening is crucial to detecting the often-symptomless pregnancy complication. Learn what these painless tests are, and why it's important to have them done during your second trimester. 

glucose test orange drink
Credit: VanHart/Shutterstock

Gestational diabetes is a condition in which your body has too much sugar (called glucose) in the blood. Seven out of every 100 pregnant women will develop it according to March of Dimes, and blood sugar that is not well controlled in a woman with gestational diabetes can lead to problems for the pregnant woman and the baby.

There are certain risk factors for developing gestational diabetes — including being over the age of 25, having a family history of diabetes, and being obese — but the U.S. Preventive Services Task Force recommends all pregnant women be screened regardless of their risk.

Why? Half of the women who develop gestational diabetes have no known risk factors

Luckily, glucose screening and glucose tolerance testing can help you detect gestational diabetes early, and give you a chance to minimize the risks of this condition. Find out when your doctor will test for gestational diabetes and what each test entails.

Glucose Screening

What to Expect:

Glucose screening is usually done between 24 and 28 weeks of pregnancy. For this test, you'll be given a syrupy (and a little unpleasant) orange glucose solution to drink. An hour after you've finished drinking the beverage, a blood sample is taken from a vein in your arm, and the glucose level is analyzed.

If the test, which screens for gestational diabetes, reveals elevated levels of blood glucose (sugar), a glucose tolerance test is then given to confirm the gestational diabetes diagnosis.

Glucose Tolerance Test

What to Expect:

If your glucose screening is found to be high (generally over 130 mg/dL), then you'll be asked to take the glucose tolerance test.

Gestational diabetes test preparation involves fasting overnight, then drinking a solution with an even higher dose of glucose. Your blood will then be sampled several times over a period of about three hours and tested for abnormal levels of glucose.

Gestational Diabetes Test Results

Test results are available immediately. If the test reveals that you have gestational diabetes, you are not alone. It is one of the most common complications of pregnancy — up to 10 percent of pregnant women in the United States must manage the condition each year according to the Centers for Disease Control and Prevention.

Gestational diabetes can be controlled by diet, exercise, or insulin. But if the elevated glucose levels remain undetected, the excess sugar in the mother's blood raises the odds of the baby being overly large, or macrosomic — generally 9 pounds, 14 ounces or more. Macrosomic babies may have difficulty fitting through the birth canal and are at risk for health problems such as jaundice, low blood calcium levels, or hypoglycemia.

The silver lining? Take comfort in the fact that gestational diabetes almost always disappears immediately after birth.

Parents Magazine