Priscilla White describes its prognostic classification based on the age of onset, duration and complications of the disorder. The biggest shortcoming of this classification is not contemplated that the metabolic instability is the main prognostic factor in insulin-dependent diabetic pregnant. In 1985, Freinkel modified White classification, as follows: (1)Classes:A: Gestational diabetesA1: fasting glucose <105 mg / dl (normal)A2: fasting glucose between 105 and 129 mg / dl (intolerant)B: fasting glucose> 130 mg / dlB1: If the diagnosis is the first time (DMG)B2: home after 20 years and under 10 years evolution, persisting between pregnancies (DM2)Classes C-D-F-H-R: correspond to the DM1 and DM2.The classification published by the National Diabetes Data Group (NDDG) (6) and endorsed by the World Health Organization (WHO) (7) in 1980 and 1985 was based on a combination of clinical features, pathogenesis and treatment requirements. She considered two types of patients: those who formed the clinical category and those that were located in a statistical risk category.In 1995, under the sponsorship of the American Diabetes Association (ADA) created an International Committee of Experts, which proposes a number of changes to the previous classification scheme, based on the literature review and in light of the new knowledge (see Table 2). (8).Remember that if you just build on them, about 35 to 50% of gestational diabetes will remain undiagnosed (1, 4).
The summary and recommendations of previous conferences working in gestational diabetes, (13-15) the screening for GDM was recommended in all pregnancies, with the premise that the DMG healthy, is one of the few institutions where with clarity can make preventive medicine. The universal screening is still recommended for women of ethnic groups with relatively high rates of intolerance to H of C during pregnancy and DM later in life. This includes women of ancestorHispanic, African, Native American, South or East Asian, Pacific Islander or Australian indigenous ancestry, particularly when they reside in western countries or in urban atmospheres. Conversely, certain characteristics are at low risk for GDM and from the standpoint of cost-effective screening is not important to these patients. Those with low risk include:Women who are not members of ethnic groups at high risk for developing DM2.
Those who have no previous history of abnormal glucose tolerance or poor obstetric outcomes usually associated with GDM, and Those who have all of the following: age <25 years, normal body weight and no family history of DM.This screening has a sensitivity ranging from 75 to 85% and specificity ranging from 85 to 90% depending on the series studied (1). It consists of administering the first prenatal (before week 20), 50 grams of glucose and determining an hour plasma glucose (pregestational DM rule) is not necessary that the patient is fasting and can be performed at any time day. If the result is normal, said screening is repeated between 24-28 weeks of gestation time in which the maximum occurs diabetogenic effect of pregnancy. A value ≥ 140 mg / dl (or ≥ 135 mg / dl if fasted overnight) requires a full study using a GTT with 100 g (see Table 3) (8).The diagnosis of GDM is made with two or more values above those listed in Table 3, where a single altered value, the test is considered pathological, presenting the risk of complications such as fetal macrosomia and preeclampsia-eclampsia. Now, the ACOG recommends that in populations with a high prevalence of GDM or francs risk factors for it, must be made directly with 100g OGTT without prior screening (12).Moreover, there have been proposals to change the diagnostic scheme scored before. Thus Carpenter and Coustan (16) proposed cutoffs for plasma glucose seem to represent more accurately the original determinations of O'Sullivan and Mahan, in other words, these extrapolations produce lower values for abnormal levels of plasma glucose and increase the number of pregnancies defined as DMG. Furthermore, additional studies have been carried out using 75 g load, as recommended by WHO, with similar results (17). In Table 4, we can observe the values for these OGTT: (9)
Similarly, diagnosis of GDM is made with two or more values than those noted above. Any of these diagnostic tests with 100g 075g is acceptable, but its sensitivity (diagnostic accuracy) and specificity should still be evaluated (9).
At six weeks postpartum, the patient should be subjected to a GTT with 75g, sampling fasting and two hours postprandial, to be reclassified as 1) diabetes, 2) impaired fasting glucose, 3) glucose intolerance or 4) normoglycemia, according to the new criteria for the diagnosis of DM (see Table 5). Are taken six weeks postpartum, since at this time the normalized insulin receptor affinity and density (1). Do not forget that in most cases of DMG, stabilize glucose returns to normal after delivery. Those normoglycemic patients considered at this time, should be evaluated for diabetes at least every year (1, 8-9).
New diagnostic criteria for DM: diagnostic criteria for DM NDDG and recommended by the WHO, (6-7) were also reviewed and amended by the ADA, for evaluation were taken a number of epidemiological studies that linked fasting glucose , two hours postprandial blood glucose and HbA1C levels