July 2022

Clinical Recommendation

The Women’s Preventive Services Initiative (WPSI) recommends screening for type 2 diabetes in individuals with a history of gestational diabetes mellitus (GDM) who are not currently pregnant and who have not previously been diagnosed with type 2 diabetes. Initial testing should ideally occur within the first year postpartum and can be conducted as early as 4–6 weeks postpartum.

Individuals who were not screened in the first year postpartum or individuals with a negative initial postpartum screening test result should be screened at least every 3 years for a minimum of 10 years after pregnancy. For those with a positive screening test result in the early postpartum period, testing should be repeated at least 6 months postpartum to confirm the diagnosis of diabetes regardless of the type of initial test (eg, fasting plasma glucose, hemoglobin A1C, oral glucose tolerance test). Repeat testing is also indicated for individuals screened with hemoglobin A1C in the first 6 months postpartum regardless of the result (see Implementation Considerations below).

Implementation Considerations

In addition to the follow-up screening for individuals with a history of GDM recommended above, the WPSI recommends adherence to diabetes screening guidelines for the general population. Guidelines for general population screening are available from the U.S. Preventive Services Task Force and American Diabetes Association.

Postpartum follow-up visits are recommended after delivery, with the initial assessment ideally within 3 weeks, a comprehensive postpartum visit by 12 weeks, and care continuing through the first year after birth. These visits provide an opportunity for screening for type 2 diabetes after GDM, especially for patients with limited access to health care after pregnancy. The WPSI recommends that postpartum visits include a discussion of future diabetes screening for individuals with history of GDM. Ongoing care with a primary care clinician is important to facilitate appropriate diabetes screening and prevention counseling after pregnancy.

Compared with other tests, hemoglobin A1C is less accurate in the first months after pregnancy and may be inaccurate in individuals with conditions such as anemia, renal failure, or certain hemoglobinopathies (eg, thalassemia and sickle cell disease or trait), or who have had a recent transfusion. However, given the low rates of postpartum testing with fasting plasma glucose and oral glucose tolerance tests, hemoglobin A1C may be considered when other tests are not feasible. By 6 months postpartum, the physiologic changes related to pregnancy have usually resolved; therefore, all standard screening tests are accurate after 6 months.

Research Recommendations

• Research evaluating the benefits and harms of screening for type 2 diabetes after gestational diabetes.
• Studies to identify tests or protocols that improve the accuracy of detecting type 2 diabetes in the immediate postpartum period, increase compliance with screening, and determine the optimal timing of diabetes testing after pregnancy. This includes research to evaluate the accuracy of random glucose tests and determine when hemoglobin A1C becomes a reliable screening test after pregnancy.
• Studies that measure the impact of weight changes, anemia correction, and lactation on diabetes screening test results.
• Research that evaluates GDM prevention strategies and programs.
• Studies that evaluate individuals with a history of GDM with initial negative screening test results after pregnancy and identify appropriate counseling strategies, determine the optimal time frame for follow-up screening, and identify predictors for the development of subsequent type 2 diabetes.