SCREENING AND DIAGNOSTIC CRITERIA FOR GESTATIONAL DIABETES MELLITUS

Abstract

Gestational diabetes mellitus (GDM) is defined as a glucose intolerance with first onset or first recognition during pregnancy. GDM is associated with higher incidence of maternal and fetal complications. Screening for GDM is recommended in most pregnant women. Assessment of risk for GDM should be performed at first prenatal visit and women at very high risk should be screened immediately using a random, fasting or post-glucose load glucose level. Most women not found to have GDM should undergo further screening at 24-28 weeks of gestation. Despite four international conferences aimed at developing a consensus definition and diagnostic criteria for GDM worldwide, the definition, screening and diagnostic criteria vary over the time making difficult to compare prevalence between countries. Most centers in Europe use World Health Organisation (WHO) diagnostic criteria which are the same as in the general population and use a 75g oral glucose tolerance test (OGTT). Current criteria used in US are based on two different protocols using one or two step-approach, 75g or 100g OGTT. Results of Hyperglycemia and Adverse Pregnancy Outcome released in 2008 have indicated a strong, continuous association between blood glucose levels below those currently used for diagnostic of diabetes and undesirable perinatal outcomes. Since the HAPO study, new, lower thresholds were proposed for the diagnostic of GDM. Implementation of these thresholds will almost double the proportion of women diagnosed with GDM.