During pregnancy, some women develop high levels of blood sugar, a condition known as gestational diabetes, or gestational diabetes mellitus. GDM typically occurs around your 24th week of pregnancy. According to the American Diabetes Association, gestational diabetes typically affects 18 percent of all pregnant women. (ADA)

    Having gestational diabetes does not mean you had diabetes before your pregnancy or that you will have it after you give birth. In most cases, gestational diabetes develops in women who never had diabetes. But some women may have had prediabetes, which means that your blood sugar is high but not enough to be diagnosed as type 1 or type 2 diabetes.

    What Causes Gestational Diabetes?

    The exact cause of gestational diabetes is unknown, but experts believe hormones play a role.

    During pregnancy, a woman’s body produces excess amounts of hormones: human placental lactogen, estrogen, and cortisol. These hormones develop in the placenta and help to sustain the pregnancy.

    Over time, the amounts of these hormones increase. They may interfere with the effects of insulin, the hormone that regulates blood sugar. Insulin helps move glucose out of the blood and into the body cells, where it produces energy. Without enough insulin, blood glucose levels go up, causing gestational diabetes.

    Who Is at Risk for Gestational Diabetes?

    The following can all increase your risk for gestational diabetes:

    • being overweight prior to pregnancy
    • a family history of diabetic disorders
    • previously giving birth to large babies (over nine pounds)
    • being over the age of 25
    • being of African American, Hispanic, or American Indian descent
    • prediabetes
    • increased blood pressure

    Recognizing the Symptoms of Gestational Diabetes

    Gestational diabetes can cause symptoms such as those that follow to develop during a pregnancy:

    • excessive thirst
    • fatigue
    • vision becomes blurred
    • excessive need to urinate
    • weight loss even when eating properly
    • infections in the bladder and other body areas
    • vomiting and nausea that is not associated with normal pregnancy

    How is Gestational Diabetes Diagnosed?

    Gestational diabetes needs to be diagnosed early to prevent problems with your health and the health of your baby. Your obstetrician normally screens you for high blood sugar between 24-28 weeks of pregnancy with an oral glucose tolerance test. The test is done in a blood lab.

    Your doctor will tell you to avoid eating in the eight hours prior to the test. A technician will take samples of your blood before giving you a special drink that contains about 100 g of sugar. The technician takes your blood, usually every hour for three hours, after drinking the liquid.

    The test is measured in milligrams per deciliter. Normal readings are:

    • before glucose test (fasting): 95 mg/dL
    • after one hour of test: 180 mg/dL
    • after two hours of test: 155 mg/dL
    • after three hours of test: 140 mg/dL

    If your blood shows higher numbers than the above for two or more tests, your doctor will suspect gestational diabetes. If your blood shows normal readings (or below) your doctor may only monitor you.

    How Is Gestational Diabetes Treated?

    Your treatment often depends on the oral glucose tolerance test results. In most cases, you may need to follow your doctor’s management plan, which includes eating healthy and exercising.


    Some women are prescribed insulin injections until delivery. If you are put on insulin, you may need to carry something sweet with you at all times. This helps you stay on track if you suddenly feel light-headed and weak, which are signs of low blood sugar. Low blood sugar is uncommon in gestational diabetes, but can occur in women taking insulin and can be dangerous.

    Home Care

    You may be advised to monitor your glucose levels daily. Your physician may supply you with a special glucose-monitoring device.

    Your doctor may suggest you do light to moderate exercise in order to lose weight or to improve your blood circulation. This may depend on how well your pregnancy is progressing, and if you do not have any other underlying ailments preventing you from exercising.

    What Is Expected in the Long Term?

    Your blood sugar will return to normal after you give birth. However, your baby may experience some complications if you do not follow your doctor’s treatment plan. These complications include:

    Mothers who had gestational diabetes are at greater risk for type 2 diabetes and obesity.