Placental iron transfer: Relationship to placental anatomy and phylogeny of the mammals

Serum iron transfer from mother to fetus was measured in near‐term pregnant females from 16 species representing 15 families and 7 orders of eutherian mammals. The amount of transfer at 2 hr was 5% or greater in species with hemochorial placentation and less than 0.1% at 3 hr in species with epitheliochorial or endotheliochorial placentation.