Abstract: Iron is an essential nutrient with crucial biological function. Sufficient amount of maternal iron store is the necessary condition to maintain the normal pregnancy. Recent studies have suggested that elevated maternal iron store is an independent risk factor of gestational diabetes mellitus（GDM）； while iron deficient anemia is a protective condition of GDM， which can reduce the incidence it. Increasing evidences suggest that oxidative stress related to high iron levels is the more likely mechanism that involved in the incidence and development of GDM.

Key words: Diabetes, gestational, Ferritins, Oxidative stress, Inflammation