A-Z Health Topics


Return to Index
by Calvagna M

Diagnosis of Gestational Diabetes

If you are at high risk of developing gestational diabetes (for example, obese , prior history of gestational diabetes or polycystic ovary syndrome, family history of diabetes), your doctor may recommend that you undergo glucose testing at your first prenatal visit. If your initial test is negative, you will be tested again later in your pregnancy.
If you are at an average risk of developing gestational diabetes, your doctor will do a screening test between 24-28 weeks of gestation.
There are different tests that can be used to diagnose gestational diabetes. These tests measure the level of glucose in your blood.

Glucose Challenge Test

The 50 gram glucose challenge test is usually done in the morning in your doctor’s office. You will drink a glucose drink that contains 50 grams of glucose. Your blood will be drawn 1 hour later.
Doctors use different screening tests and cutoff values to make a diagnosis. Generally, these values at 1 hour range from 130 mg/dL (7.2 mmol/L) to 140 mg/dL (7.8 mmol/L). If your blood glucose is abnormally high at 1 hour, you will need to take a 3-hour glucose tolerance test to comfirm the diagnosis.

Other Tests

In addition to the above screening tests, additional tests may include:
  • HbA1c test (shows average glucose levels the past 2-4 months)
  • Urine tests
  • Thyroid function tests
  • Tests to monitor the fetus (for example, ultrasound )

References

Gestational diabetes mellitus (GDM). EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated September 10, 2015. Accessed September 16, 2015.
Screening and diagnosis of gestational diabetes mellitus. Committee Opinion No. 504. American Congress of Obstetricians and Gynecologists. Obstet Gynecol. 2011;118:751-753.
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 August 2013. Accessed September 16, 2015.

Revision Information

HIPAA Disclaimer. We are not "HIPAA compliant." Users are solely responsible for any applicable compliance with federal or state laws governing the privacy and security of personal data, including medical or other sensitive data. Users acknowledge that the Services may not be appropriate for the storage or control of access to sensitive data, such as information about children or medical or health information. sfmc.net does not control or monitor the information or data you store on, or transmit through, our Services. We specifically disclaim any representation or warranty that the Services, as offered, comply with the federal Health Insurance Portability and Accountability Act ("HIPAA"). Customers requiring secure storage of "protected health information" under HIPAA are expressly prohibited from using this Service for such purposes. Storing and permitting access to "protected health information," as defined under HIPAA is a material violation of this User Agreement, and grounds for immediate account termination. We do not sign "Business Associate Agreements" and you agree that sfmc.net is not a Business Associate or subcontractor or agent of yours pursuant to HIPAA.