Hematologic parameters and iron state in the perinatal period.

In 51 unselected mothers, we studied, before and after delivery: serum ferritin, serum iron, serum transferrin, the erythrocyte count, the hemoglobin concentration, the hematocrit, and the derived red cell indices. Eighteen percent of women showed a hemoglobin value below 120 g/l. The mean transferrin saturation (22 +- 7.6% (SD) and the mean serum ferritin (34 +/- 18 micrograms/l (SD) indicated a probable decrease of iron stores at term. Only three patients seemed to show hematological evidence of latent iron deficiency, and none had manifest iron deficiency. A decrease of iron stores is considered to be physiological. There was no apparent relation between iron store values and infant birth weight centiles. After delivery the changes in red blood indices showed a close correlation with the amount of blood lost during delivery. At 5 or 6 days post partum the serum ferritin level increased and values showed a wide scatter. As with other acute phase proteins, ferritin synthesis might be stimulated by the non-specific mechanisms during the perinatal period. Hence, after normal delivery serum ferritin levels do not necessarily indicate normal iron stores.