Placental Transfer of Iron in Swine as a Function of Gestation Age. ∗

Summary

Results of radio-chemical studies with 9 pregnant and 3 control gilts dosed intravenously with a single tracer injection 6f Fe⁵⁹ citrate, and sacrificed after 48 hours, indicated Fe⁵⁹ values to increase 7-fold between 35 and 70, and 5-fold from 70 to 105 days gestation, respectively. Total fetal iron content increased from 0.18 mg at 35 days to 4.3 and 14.9 mg at 70 and 105 days, respectively. Fetal liver and spleen exhibited greatest contribution to hematopoiesis during early gestation, while these organs and red bone marrow became increasingly important as pregnancy advanced. Results of this study indicated that iron is transferred across the placental membranes of swine at each trimester, with quantity and rate increasing progressively with each stage of gestation.