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U.S. Preventive Services Task Force

Screening for Gestational Diabetes Mellitus

Clinical Summary of a U.S. Preventive Services Task Force Recommendation

This document is a summary of the 2008 recommendation of the U.S. Preventive Services Task Force (USPSTF) on screening for gestational diabetes mellitus. This summary is intended for use by primary care clinicians.

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Population Pregnant Women Who Have Not Previously Been Diagnosed With Diabetes
Recommendation No Recommendation due to insufficient evidence*
Grade: I
Risk Assessment
Women at increased risk of developing gestational diabetes mellitus (GDM) include those who:
  • Are obese.
  • Are older than 25 years.
  • Have a family history of diabetes.
  • Have a history of GDM.
  • Are of certain ethnic groups (Hispanic, American Indian, Asian, or African-American).
Rationale for No Recommendation
The current evidence is insufficient to assess the balance between the benefits and harms of screening women for GDM either before or after 24 weeks gestation. Harms of screening include short-term anxiety in some women with positive screening results, and inconvenience to many women and medical practices because most positive screening tests are likely false-positives.
Suggestions for Practice
Until there is better evidence, clinicians should discuss screening for GDM with their patients and make case-by-case decisions. The discussion should include information about the uncertain benefits and harms as well as the frequency and uncertain meaning of a positive screening test result.
Screening Tests
If a decision is made to screen for GDM:
The screening test most commonly used in the United States is an initial 50-gram 1-hour glucose challenge test (GCT). If the result on the GCT is abnormal, the patient undergoes a 100-gram 3-hour oral glucose tolerance test (OGTT). Two or more abnormal values on the OGTT are considered a diagnosis of GDM.
Screening Intervals
Most screening is conducted between 24 and 28 weeks gestation. There is little evidence about the value of earlier screening.
Other Approaches to Prevention
Nearly all pregnant women should be encouraged to:
  • Achieve moderate weight gain based on their pre-pregnancy body mass index.
  • Participate in physical activity.
*The current evidence is insufficient to establish the balance of benefits and harms for screening for gestational diabetes mellitus, either before or after 24 weeks gestation.

For a summary of the evidence systematically reviewed in making this recommendation, please go to the full recommendation statement, and supporting documents.

Copyright and Source Information

This document is in the public domain within the United States.

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AHRQ Publication No. 08-05115-EF-3
Current as of May 2008

Internet Citation:

U.S. Preventive Services Task Force. Screening for Gestational Diabetes Mellitus: Clinical Summary of U.S. Preventive Services Task Force Recommendation. AHRQ Publication No. 08-05115-EF-3, May 2008. http://www.uspreventiveservicestaskforce.org/uspstf08/gestdiab/gdsumm.htm


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