Placenta plays an important role in maintaining iron transport to fetus. This process of iron transport is purely a placental function over which mother and fetus have no control, as placenta continues to trap iron even when fetus is removed in animals (Fletcher & Sute Clin Sci 1969). In spite of this efficient protective mechanism the placental iron content reduces significantly in maternal hypoferriemia (Agarwal et al .Am J Clin Nutr 1979, Acta Paediatr 1978 & 1984). This was a very important finding as earlier studies by Vahlquist 1941; ACTA Paediatr, on Swedish women had shown that cord iron does not change in iron deficient pregnant women. This was also observed by Rios et al Pediatrics 1975.
The placenta of anemic women showed qualitative decrease in villous surface area, volume of villi and length of blood vessel, while surface area and volume of intervillous space was increased. These placental changes in anemia did not normalise on rehabilitation- suggesting “Maturational arrest”(Agarwal et al; Indian J Path Micro 1979; J Trop Paediatr 1981; Proc Nutr Soc of India 1991).
b) Fetal Liver iron stores are reduced significantly in maternal hypoferremia. Normally bigger the infant and more advanced the gestational age higher was the amount of iron in fetal liver, spleen and kidney. The tissue iron content increases steeply in last 8 weeks of gestation. Infant born before 36 weeks of gestation, had half the iron content in hepatic reserve (Agarwal et al; Acta Pediatr1985).