LEP and Insulin resistance: Several mechanisms have been proposed including the adaptive process to increase energy expenditure, the influence of leptin, changes in the activity of deiodinases, the chronic low-grade inflammation, and the presence of insulin resistance (37, 38).Gestation implies an increased burden on thyroid gland, which not only stimulates a higher production of THs but also might promote a compensation mechanism by slightly increasing TSH and THs production (within normal range) for maintenance of glucose homeostasis (39).