Your doctor should assess your risk for gestational diabetes at your first prenatal visit. If you already have diabetes and you become pregnant, then you do not need to be screened for gestational diabetes.
If you are at high risk of developing gestational diabetes (eg, obesity, family history for type 2 diabetes, previous history of gestational diabetes), your doctor may recommend that you undergo glucose tolerance testing as soon as possible. If your initial test is negative, you will be retested between 24 and 28 weeks of gestation.
If you are at average risk, your doctor will give you a screening test between 24-28 weeks of gestation.
You may not need to be screened if you are at low risk for gestational diabetes. But, to be low risk, you must meet all of the following criteria:
For the 50-gram glucose screening test, you do not need to fast. You are given a drink that contains 50 grams of glucose. One hour later, your blood sugar level is tested.
Note: There are different screening tests that doctors use, as well as different cut-off levels to make a diagnosis.
Gestational diabetes mellitus (GDM). EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/ . Updated July 11, 2012. Accessed August 17, 2012.
Screening for gestational diabetes mellitus. The Society of Obstetricians and Gynaecologists of Canada website. Available at: http://www.sogc.org/guidelines/public/121E-CPG-November2002.pdf . Published November 2002. Accessed August 20, 2012.
What I need to know about gestational diabetes. National Diabetes Information Clearinghouse (NDIC) website. Available at: http://diabetes.niddk.nih.gov/dm/pubs/gestational/#7 . Updated December 6, 2011. Accessed August 17, 2012.
Last reviewed September 2012 by Andrea Chisholm
Last Updated: 09/11/2012