Screening for Diabetes Mellitus after Pregnancy
The Women’s Preventive Services Initiative recommends women with a history of gestational diabetes mellitus (GDM) who are not currently pregnant and who have not previously been diagnosed with type 2 diabetes mellitus should be screened for diabetes mellitus. Initial testing should ideally occur within the first year postpartum and can be conducted as early as 4–6 weeks postpartum (see Table 1).
Women with a negative initial postpartum screening test result should be rescreened at least every 3 years for a minimum of 10 years after pregnancy. For women with a positive postpartum screening test result, testing to confirm the diagnosis of diabetes is indicated regardless of the initial test (eg, oral glucose tolerance test, fasting plasma glucose, or hemoglobin A1c).
Repeat testing is indicated in women who were screened with hemoglobin A1c in the first 6 months postpartum regardless of the result (see Implementation Considerations below).
In addition to the follow-up screening for women with a history of GDM recommended above, the Women’s Preventive Services Initiative recommends all women should adhere to diabetes mellitus 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.
Compared with other tests, hemoglobin A1c is less accurate in the first months after pregnancy. In addition, hemoglobin A1c levels may be inaccurate in women with conditions such as anemia, renal failure, certain hemoglobinopathies (eg, thalassemia and sickle cell disease or trait) or women who have had a recent transfusion. However, given the low rates of postpartum testing with fasting plasma glucose and 2-hour 75-gram oral glucose tolerance tests, hemoglobin A1c may be considered as an alternative for appropriately counseled patients 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 acceptable after 6 months.
1. Determine the optimal timing of diabetes mellitus testing after pregnancy
2. Establish when hemoglobin A1c becomes a reliable screening test after pregnancy
3. Develop methods for improving compliance with postpartum testing for both patients and providers
4. Measure the impact of weight changes, anemia correction, and lactation on screening test results
5. Identify tests or protocols that improve accuracy for detecting diabetes mellitus in the immediate postpartum period
6. Establish time frame for continuing screening women with initial negative screening test results
7. Identify appropriate counseling strategies for women with negative screening test results
8. Determine what predictors lead to the development of diabetes mellitus in women with initial negative screening test results
9. Develop GDM prevention strategies and programs
*These are the recommendations of the WPSI and not necessarily of any individual participating organization.