Screening for Gestational Diabetes

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Screening for Gestational Diabetes

Topic Overview

Early detection

The first time you see your doctor after you become pregnant, your doctor will determine your risk for gestational diabetes. If you are considered high risk because you have had gestational diabetes before, are obese, have a strong family history of type 2 diabetes, or have sugar in your urine, you will be tested right away.

Most women are tested between the 24th and 28th weeks of pregnancy. Some pregnant women are at low risk for developing gestational diabetes and may not need to be tested. You may not benefit from testing if:

  • You are younger than 35 when you become pregnant.
  • You have not had gestational diabetes before.
  • You have no family history of type 2 diabetes.
  • Your body mass index[BMI] is less than 30.
  • You are not a member of a racial or ethnic group that has a high risk for developing diabetes, such as women of Latin, First Nations, Asian, African, or Polynesian descent.
  • You do not have polycystic ovary syndrome.

Experts debate whether all pregnant women need to be tested for gestational diabetes. For example, the Canadian Diabetes Association (CDA) recommends screening for all pregnant women, while the U.S. Preventive Services Task Force has found insufficient evidence to recommend screening women with no risk factors for gestational diabetes.1, 2 But most doctors routinely test all pregnant women who are in their care.

After delivery

Even though your gestational diabetes will probably go away after your baby is born, you are at risk for developing gestational diabetes again and for developing type 2 diabetes later in life. More than half of women who develop gestational diabetes will develop type 2 diabetes later in life.3

To make sure your blood sugar level stays within a target range, your doctor may tell you to continue checking your blood sugar levels at home for a while. You will also have a follow-up glucose tolerance test 6 weeks to 6 months after your baby is born or after you stop breast-feeding your baby. If the results of this test are normal, you will still need to have a fasting blood sugar test at least every 3 years. If that test shows that your blood sugar is slightly high, you may have a condition called prediabetes. If you have prediabetes, you can help prevent type 2 diabetes by changing the way you eat, exercising regularly, and being tested for diabetes every year. For more information, see the topic Prediabetes.

Women who had gestational diabetes and use progestin-only birth control pills may have a greater chance of developing type 2 diabetes. Combination birth control pills that contain estrogen and progestin are not linked with an increased risk of type 2 diabetes. But these pills cannot be used by women who are breast-feeding. Talk to your doctor about the best kind of contraception for you.4

If you want to get pregnant again, you should be tested for diabetes before you become pregnant and also early in your pregnancy.

For more information, see the topic Gestational Diabetes.

Related Information



  1. Canadian Diabetes Association (2008). Clinical practice guidelines for the prevention and management of diabetes in Canada. Available online:
  2. U.S. Preventive Services Task Force (2008). Screening for gestational diabetes mellitus. Available online:
  3. Cunningham FG, et al. (2005). Gestational diabetes. In Williams Obstetrics, 22nd ed., pp. 1172–1187. New York: McGraw-Hill.
  4. Brown FM (2005). Diabetes and pregnancy. In CR Kahn et al., eds., Joslin's Diabetes Mellitus, 14th ed., pp. 1035–1047. Philadelphia: Lippincott Williams and Wilkins.


By Healthwise Staff
Primary Medical Reviewer Anne C. Poinier, MD - Internal Medicine
Specialist Medical Reviewer Alan C. Dalkin, MD - Endocrinology
Specialist Medical Reviewer Donald Sproule, MD, CM, CCFP, FCFP - Family Medicine
Last Revised February 10, 2010

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