Historias clinicas

 
Published in Volume 115, Issue 3 (March 1, 2005)
J Clin Invest. 2005;115(3):485–491. doi:10.1172/JCI24531.
Copyright © 2005, American Society for Clinical Investigation
Citations reported by PubMed Central (30)
Science in Medicine
Gestational diabetes mellitus
Thomas A. Buchanan1 and Anny H. Xiang2
1Departments of Medicine, Obstetrics and Gynecology, and Physiology and Biophysics,and
2Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, California, USA.
Address correspondence to: Thomas A. Buchanan, Room 6602 GNH, 1200 North State Street, Los Angeles, California 90089-9317, USA. Phone: (323) 226-4632; Fax: (323) 226-2796; E-mail: buchanan@usc.edu.
Published March 1, 2005
Gestational diabetes mellitus (GDM) isdefined as glucose intolerance of various degrees that is first detected during pregnancy. GDM is detected through the screening of pregnant women for clinical risk factors and, among at-risk women, testing for abnormal glucose tolerance that is usually, but not invariably, mild and asymptomatic. GDM appears to result from the same broad spectrum of physiological and genetic abnormalities thatcharacterize diabetes outside of pregnancy. Indeed, women with GDM are at high risk for having or developing diabetes when they are not pregnant. Thus, GDM provides a unique opportunity to study the early pathogenesis of diabetes and to develop interventions to prevent the disease.
Historical perspective
For more than a century, it has been known that diabetes antedating pregnancy can have severe adverseeffects on fetal and neonatal outcomes (1). As early as in the 1940s, it was recognized that women who developed diabetes years after pregnancy had experienced abnormally high fetal and neonatal mortality (2). By the 1950s the term “gestational diabetes” was applied to what was thought to be a transient condition that affected fetal outcomes adversely, then abated after delivery (3). In the1960s, O’Sullivan found that the degree of glucose intolerance during pregnancy was related to the risk of developing diabetes after pregnancy. He proposed criteria for the interpretation of oral glucose tolerance tests (OGTTs) during pregnancy that were fundamentally statistical, establishing cut-off values — approximately 2 standard deviations — for diagnosing glucose intolerance during pregnancy(4). In the 1980s those cut-off points were adapted to modern methods for measuring glucose and applied to the modern definition of gestational diabetes — glucose intolerance with onset or first recognition during pregnancy (5). While based on O’Sullivan’s values for predicting diabetes after pregnancy, the diagnosis of gestational diabetes mellitus (GDM) also identifies pregnancies at increased riskfor perinatal morbidity (6–8) and long-term obesity and glucose intolerance in offspring (9–11).
Population perspective
Clinical detection of GDM is carried out to identify pregnancies at increased risk for perinatal morbidity and mortality. Available data do not identify a threshold of maternal glycemia at which such risk begins or increases rapidly. A multinational study, the Hyperglycemiaand Adverse Pregnancy Outcome study, is underway to explore this issue in a large multiethnic cohort. In the absence of a defined glucose threshold for perinatal risk, many different sets of glycemic criteria have been proposed and are employed worldwide for the diagnosis of GDM. The criteria currently recommended by the American Diabetes Association (12) are based on O’Sullivan’s criteria (seeabove). The detection of GDM, a condition that is generally asymptomatic, involves screening in 2 sequential steps, followed by administration of a 2- or 3-hour OGTT to women determined to be at risk by screening. The frequency of GDM may vary among ethnic groups (higher in groups with increased prevalence of hyperglycemia) (13–16) and with the use of different diagnostic criteria (higher when lower...