Abstract

Gestational diabetes mellitus is diabetes diagnosed in the second or third trimester of pregnancy that was not clearly overt diabetes prior to gestation. This is also helpful for diagnosing unrecognized pre-existing diabetes. Gestational diabetes mellitus is an aggravating factor for the risk of future diabetes in both the mother and child and represents glycaemic dysregulation. In order to prevent an adverse event in the course of pregnancy and post-partum, it is important to screen, diagnose and treat hyperglycemia in pregnancy. Over the years, different diagnosing criteria with regards to maternal and fetal outcomes for the diagnosis of GDM have always been a problem. Universal Screening is recommended always for pregnant women belonging to a high risk ethnic population like Indians. According to DIPSI, a single step 75g of glucose non-fasting Oral Glucose Tolerance Test (OGTT) with a cut-off of ≥ 140 mg/dl after 2-hours is diagnostic of GDM, whereas a fasting OGTT after 75g glucose with a cut-off plasma glucose of ≥ 140 mg/dl after 2-hour is recommended by WHO. For screening of women at risk of diabetes, the ADA/IADPSG criteria recommends, for diagnosis of GDM in the first and subsequent trimester at 24-28 weeks by 75 g OGTT and fasting 92 mg/dl, 1 hour 180 mg/dl, 2 hour 153 mg/dl by universal glucose tolerance testing. There is an air of controversy regarding over diagnosis of GDM and unnecessary interventions. The ACOG still prefer a 2 step procedure, GCT with 50g glucose non-fasting if value > 140 mg/dl followed by 3-hour OGTT for confirmation of diagnosis. In conclusion, based on Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study, as mild degree of dysglycemia are associated with adverse outcome and high prevalence of Type 2 DM in later life, the IADPSG criteria is recommended. The only outcome based criteria is the IADPSG criteria as it has the ability to diagnose and treat GDM earlier, thereby reducing the fetal and maternal complications associated with GDM. It is simple in execution, more patient friendly, diagnostically accurate, single step procedure and close to international consensus. Due to the diversity and variability of Indian population, application of single international criteria may not be conclusive. This warrants further comparative studies on different diagnostic criteria in relation to adverse pregnancy outcomes.