Red cell and plasma ferritin in a group of normal fetuses at different ages of gestation.
Plasma and cell ferritin were determined in 47 normal fetuses at different gestational ages in order to evaluate fetal iron status. Plasma ferritin shows an increase during pregnancy (17.7 micrograms/l-mean geometrical value of fetuses between 18 and 20 weeks; 56.8 micrograms/l mean geometrical value of fetuses between 32 and 35 wk) and significantly correlates to hemoglobin and number of red blood cells. Red cell ferritin, too, increases throughout pregnancy (from 92.7 ag/cell to 265 ag/cell) and shows a better correlation to hemoglobin and number of red blood cells. Experimental evidence has been provided showing that the placenta takes up ferritin and is important in iron storage and transport (even against a concentration gradient). Our data support this theory and suggest a situation of positive balance between iron uptake and utilization during intrauterine life.