This document reflects emerging clinical and scientific advances as of the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed.
ABSTRACT: Establishing the diagnosis of gestational diabetes mellitus offers an opportunity not only to improve pregnancy outcome, but also to decrease risk factors associated with the subsequent development of type 2 diabetes. The American College of Obstetricians and Gynecologists' Committee on Obstetric Practice recommends that all women with gestational diabetes mellitus be screened at 6–12 weeks postpartum and managed appropriately.
Gestational diabetes mellitus (GDM), defined as carbohydrate intolerance leading to hyperglycemia with onset or first recognition during pregnancy, affects 2–10% of pregnancies in the United States depending on the characteristics of the population studied (1). Gestational diabetes mellitus is characterized by insulin resistance that is specific to pregnancy. This Committee Opinion augments ACOG Practice Bulletin No. 30: Gestational Diabetes (2) by highlighting recent thinking about the risk for diabetes mellitus among women whose pregnancies were affected by GDM, and presents recommendations for screening and management for these women.
Although the carbohydrate intolerance of GDM frequently resolves after delivery (3, 4), up to one third of affected women will have diabetes or impaired glucose metabolism at postpartum screening, and it has been estimated that 15–50% will develop diabetes in the decades following the affected pregnancy (5–12). The original cutoff points for performing an abnormal glucose tolerance test in pregnancy were chosen for their ability to predict the subsequent onset of type 2 diabetes mellitus (13). Postpartum screening at 6–12 weeks has been recommended for women who had GDM to identify women with diabetes mellitus, or impaired fasting glucose level, or impaired glucose tolerance (14, 19). The latter two may respond to life-style modification and pharmacologic interventions to decrease incident diabetes. However, there is marked variability in the proportion of women with GDM who are screened postpartum as well as in the type of screening used (6–7, 9, 15–20).
Either a fasting plasma glucose test or the 75-g, 2-hour oral glucose tolerance test are appropriate for diagnosing diabetes. Although the fasting plasma glucose test is easier to perform, it lacks sensitivity for detecting other forms of abnormal glucose metabolism; results of the oral glucose tolerance test can confirm an impaired fasting glucose level and impaired glucose tolerance (see Table 1). In light of this, the Fifth International Workshop on GDM recommended that women with GDM undergo a 75-g oral glucose tolerance test 6–12 weeks postpartum (21).
Establishing the diagnosis of GDM offers an opportunity not only to improve pregnancy outcome, but also to affect risk factors associated with the subsequent development of type 2 diabetes. The American College of Obstetricians and Gynecologists' Committee on Obstetric Practice recommends that all women with GDM be screened at 6–12 weeks postpartum and managed appropriately (see Fig. 1). The American Diabetes Association recommends repeat testing at least every 3 years for women who had a pregnancy affected by GDM and normal results of postpartum screening (14). For women who may have subsequent pregnancies, screening more frequently has the advantage of detecting abnormal glucose metabolism before pregnancy and provides an opportunity to ensure preconception glucose control (21). Women should be encouraged to discuss their GDM history and need for screening with all of their health care providers.
- Hunt KJ, Schuller KL. The increasing prevalence of diabetes in pregnancy. Obstet Gynecol Clin North Am 2007; 34:173–99, vii.
- Gestational diabetes. ACOG Practice Bulletin No. 30. American College of Obstetricians and Gynecologists. Obstet Gynecol 2001;98:525–38.
- Kaaja RJ, Greer IA. Manifestations of chronic disease during pregnancy. JAMA 2005;294:2751–7.
- Buchanan TA, Xiang AH. Gestational diabetes mellitus. J Clin Invest 2005;115:485–91.
- Russell MA, Phipps MG, Olson CL, Welch HG, Carpenter MW. Rates of postpartum glucose testing after gestational diabetes mellitus. Obstet Gynecol 2006;108:1456–62.
- Kim C, Tabaei BP, Burke R, McEwen LN, Lash RW, Johnson SL, et al. Missed opportunities for type 2 diabetes mellitus screening among women with a history of gestational diabetes mellitus. Am J Public Health 2006;96:1643–8.
- Smirnakis KV, Chasan-Taber L, Wolf M, Markenson G, Ecker JL, Thadhani R. Postpartum diabetes screening in women with a history of gestational diabetes. Obstet Gynecol 2005;106:1297–303.
- Schaefer-Graf UM, Buchanan TA, Xiang AH, Peters RK, Kjos SL. Clinical predictors for a high risk for the development of diabetes mellitus in the early puerperium in women with recent gestational diabetes mellitus. Am J Obstet Gynecol 2002;186:751–6.
- Conway DL, Langer O. Effects of new criteria for type 2 diabetes on the rate of postpartum glucose intolerance in women with gestational diabetes. Am J Obstet Gynecol 1999;181:610–4.
- Albareda M, Caballero A, Badell G, Piquer S, Ortiz A, de Leiva A, et al. Diabetes and abnormal glucose tolerance in women with previous gestational diabetes. Diabetes Care 2003;26:1199–205.
- Lee AJ, Hiscock RJ, Wein P, Walker SP, Permezel M. Gestational diabetes mellitus: clinical predictors and long-term risk of developing type 2 diabetes: a retrospective cohort study using survival analysis. Diabetes Care 2007;30: 878–83.
- Kim C, Newton KM, Knopp RH. Gestational diabetes and the incidence of type 2 diabetes: a systematic review. Diabetes Care 2002;25:1862–8.
- O'Sullivan JB, Mahan CM. Criteria for the oral glucose tolerance test in pregnancy. Diabetes 1964;13:278–85.
- American Diabetes Association. Standards of medical care in diabetes—2008. Diabetes Care 2008;31(suppl 1):S12–54.
- Gabbe SG, Gregory RP, Power ML, Williams SB, Schulkin J. Management of diabetes mellitus by obstetrician-gynecologists. Obstet Gynecol 2004;103:1229–34.
- Dacus JV, Meyer NL, Muram D, Stilson R, Phipps P, Sibai BM. Gestational diabetes: postpartum glucose tolerance testing. Am J Obstet Gynecol 1994;171:927–31.
- Almario CV, Ecker T, Moroz LA, Bucovetsky L, Berghella V, Baxter JK. Obstetricians seldom provide postpartum diabetes screening for women with gestational diabetes. Am J Obstet Gynecol 2008;198:528.e1–528.e5.
- Hunt KJ, Conway DL. Who returns for postpartum glucose screening following gestational diabetes mellitus? Am J Obstet Gynecol 2008;198:404.e1–404.e6.
- Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin JM, Walker EA, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. Diabetes Prevention Program Research Group. N Engl J Med 2002;346:393–403.
- Dietz PM, Vesco KK, Callaghan WM, Bachman DJ, Bruce FC, Berg CJ, et al. Postpartum screening for diabetes after a gestational diabetes mellitus-affected pregnancy. Obstet Gynecol 2008;112:868–74.
- Metzger BE, Buchanan TA, Coustan DR, de Leiva A, Dunger DB, Hadden DR, et al. Summary and recommendations of the Fifth International Workshop-Conference on Gestational Diabetes Mellitus [published erratum appears in Diabetes Care 2007;30:3154]. Diabetes Care 2007;30 (suppl 2):S251–60.
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Postpartum Screening for Abnormal Glucose Tolerance in Women Who Had Gestational Diabetes Mellitus. ACOG Committee Opinion No. 435. American College of Obstetricians and Gynecologists. Obstet Gynecol 2009;113:1419–21.