Evaluation of the iron status (haemoglobin and ferritin concentrations, and percentage transferrin saturation) in a prospective study of 65 pregnant women (55 white and 10 black) revealed that adequate maternal iron stores during pregnancy cannot be maintained with prevailing dietary patterns. Although 80,6% of the patients had normal indices in the first trimester, only 12,3% were normal in the third. Significant depletion of iron stores occurred in the second trimester, but significant iron-deficient erythropoiesis only occurred in the third trimester. Despite the decline in iron status, iron deficiency anaemia was only seen in 7 - 8% of the patients. Even after correction for the haemodilution and increased transferrin concentrations in pregnancy, over 70% of women had depleted iron stores in the third trimester. No beneficial effect on fetal birth weights was found on withholding of maternal iron supplementation. This study clearly demonstrated that white and urban black pregnant women require iron prophylaxis to maintain iron stores