 75 gm Oral Glucose Tolerance Test OGTT was done in pregnant patients. Blood sugar fastingBSF 5.5 mmoll 2 hours postprandial 7.8 mmoll was labelled as GDM. They were randomised to metformin or insulin group. Those assigned to metformin group were started metformin 500mg twice daily increased until 2500mg depending on the blood sugar levels. Aim was to achieve blood sugar levels of BSF 5.3 mmoll and 1 hour post meal7.8mmoll. If blood sugar levels were not controlled, insulin was added. The insulin group was given 3 injections of regular insulin one intermediate acting insulin injection at night subcutaneously. Both groups were followed till delivery and outcome studied 