Obstetricians use a unique form of classification of diabetes in pregnancy originally proposed by Dr. Priscilla White.<sup>94 White P. Pregnancy complicating diabetes Am J Med 1949 ;  7 : 609-616  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> The system was designed to estimate the prognosis for pregnancy outcome for women with diabetes who become pregnant. White first described her classification system in a report entitled, “Pregnancy Complicating Diabetes.” The prognostic system was based on the observation that women in whom diabetes was diagnosed at an earlier age, was of longer duration, or produced vascular complications had a poorer pregnancy prognosis. From an obstetric point of view, diabetes is thought to complicate pregnancy. A large amount of resources is committed to finding, monitoring, and treating diabetes first diagnosed during and presumably induced by pregnancy. White never included an induced form of diabetes in her original classification system; class A diabetes was, in her scheme, subclinical or chemical diabetes that nonetheless preceded pregnancy.

Few pregnant women have had a pregestational diagnosis of diabetes. Validated observations about high rates of fetal morbidity and mortality in women with diabetes induced speculation that unexplained morbidity and mortality might be attributed to undiagnosed diabetes.<sup>31 Frienkel N. Gestational diabetes 1979: Philosophical and practical aspects of a major public health problem Diabetes Care 1980 ;  3 : 399-401

Haga clic aquí para ir a la sección de Referencias</sup> Nonetheless, this latter complication of pregnancy has failed to account for a measurable number of pregnancy losses, and, ironically, the undiagnosed but likely overt diabetic has received little attention until recently in comparison with concern about glucose intolerance and its benign consequences in a much larger number of women.

Another irony in diabetes and pregnancy is the persistent use of glucose tolerance testing in pregnancy. O'Sullivan and Mahan<sup>78 O'Sullivan J.B., Mahan C.M. Criteria for the glucose tolerance test in pregnancy Diabetes 1964 ;  13 : 278-285

Haga clic aquí para ir a la sección de Referencias</sup> evaluated glucose tolerance tests in pregnant women to establish thresholds that were analogous to those used in nonpregnant individuals. Internal medicine specialists subsequently abandoned glucose tolerance testing as inaccurate. Recently, the American Diabetes Association<sup>63 Metzger B.E., Coustan D.R., The Organizing Committee Summary and recommendations of the Fourth International Workshop-Conference on gestational diabetes mellitus Diabetes Care 1998 ;  21 : B161

Haga clic aquí para ir a la sección de Referencias</sup> has endorsed not only the unique classification system for diabetes in pregnancy that has been used for decades by obstetricians but also the continued use of oral glucose tolerance tests to screen and diagnose diabetes in pregnancy. Despite arguing that universal screening of pregnant women is not supportable because a diagnosis that cannot be predicted on the basis of risk factors is questionable, the association endorsed lower diagnostic thresholds that will increase the prevalence of the diagnosis with little evidence that this change will improve the care and outcome of pregnancies.

Significant changes have occurred over the last 10 years in the diagnosis and treatment of diabetes that impact on pregnancy occurrence in women with diabetes and that affect pregnant women newly diagnosed with diabetes. The Diabetes Care and Complications Trial<sup>27 Diabetes Control and Complications Trial Research Group The effect of pregnancy on microvascular complications in the diabetes control and complications trial Diabetes Care 2000 ;  23 : 1084-1091

Haga clic aquí para ir a la sección de Referencias</sup> has demonstrated that more strict glycemic normalization reduces the frequency and severity of complications of diabetes and may improve pregnancy outcomes if women are in better glycemic control when they conceive. If the recently reported success of pancreatic islet cell transplants results in widespread availability of this therapeutic modality, the problem of poor periconceptual control may be replaced by a need to consider the impact of new immunosuppressive therapies on the pregnancy.<sup>50 Langer O. , y al. A comparison of glyburide and insulin in women with gestational diabetes mellitus N Engl J Med 2000 ;  343 : 1134-1138  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> Recommendations have changed regarding the diagnosis of diabetes in nonpregnant individuals. The long-standing diagnostic threshold of a fasting glycemic level of 140 mg/dL has been lowered to 126 mg/dL. As a result, the incidence of diabetes will rise, and there is concern that the incidence of diabetes is increasing independently of diagnostic criteria changes owing to an increase in risk factors in the population.<sup>39 Harris M.I., Flegal K.M., Cowie C.C. , y al. Prevalence of diabetes, impaired fasting glucose, and impaired glucose tolerance in US adults: The third National Health and Nutrition Examination Survey, 1988–1994 Diabetes Care 1998 ;  21 : 518-524  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> The primary risk factor of concern is the current “epidemic of obesity.” It is hoped that earlier diagnosis and treatment of diabetes will reduce the incidence and severity of complications of hyperglycemia. Insofar as gestational diabetes is a risk factor for the subsequent development of diabetes in the nonpregnant individual, the importance of the diagnosis in pregnancy would seem to be increased.