Gestational diabetes mellitus (GDM) is a disturbance in glucose metabolism, which is diagnosed during pregnancy and affects pregnant women. The incidence of gestational diabetes has been increasing the last 20 years. The longitudinal changes in carbohydrate metabolism during gestation are integral to a successful pregnancy outcome for both mother and fetus. Therefore, prevention of any disease particularly non-communicable diseases includes four steps that include primary prevention, post primary prevention, secondary prevention and tertiary prevention. The steps are taken after diagnosing some form of abnormal glucose tolerance like impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) are called post primary prevention. There are two components for the development of any disease, the genetic and the environmental factors. Of the two, there are evidences to establish the fact that the intra uterine environment plays a vital role in the development of diabetes. Intrauterine exposure to hyperglycemia during the critical period of fetal development programs the development of pancreas  relatively and affects insulin secretion function. Further maternal hyperglycemia has a direct effect on the fetal pancreas and is associated with the increased susceptibility to future diabetes in the infant. Women with a history of gestational diabetes mellitus as well as their children are at increased risk of future diabetes, predominantly type II diabetes. During pregnancy, there is a significant alteration in glucose homeostasis secondary to the complex hormonal changes and increased metabolic demands of gravid uterus, its contents, and the mother. The rise in the hormones includes estrogen, progesterone,human placental lactogen and cortisol that alters this metabolism is largely responsible for the altered homeostasis.