In 1960, O’ Sullivan et al., proposed that screening, diagnosis and treatment of Hyperglycemia in women who are not a known DM improve outcomes. They proposed diagnostic criteria for GDM based on 3-hour 100g glucose OGTT and then they validated these criteria for the development of future DM in the mother [10]. There is no consensus regarding screening and diagnostic methods for GDM. Screening and diagnostic methods can be universal or risk based one step or two step procedure. Risk factors for GDM include obese women, BMI above 30 kg/m2, previous macrosomic baby weighting 4.5 kg or above, previous GDM, family history of DM (first degree relative with DM), ethnic family origin with a high prevalence of DM, clinical conditions associated with insulin resistance like PCOD, acanthosis nigricans, history of hypertension or hypercholesterolaemia.