OBJECTIVES: The purpose of this study was to determine the impact of iron status on cadmium dose among pregnant women. METHODS: Iron status and cadmium concentration in blood, urine, and placenta were determined among women followed for 2 years from early pregnancy. RESULTS: Blood cadmium and urinary cadmium were correlated with iron status throughout the study period. Urinary cadmium increased longitudinally among women with exhausted iron stores during their pregnancy. The increase in urinary cadmium with age was more pronounced in multiparous than in nulliparous women. CONCLUSIONS: Iron deficiency during pregnancy leads to increased cadmium absorption and body burden. Multiparous women exhibit additional increases with increasing age.