Relationship of maternal and newborn (cord) serum ferritin concentrations measured by immunoradiometry.

Serum ferritin concentration was determined by immunoradiometry in venous blood samples of 45 pregnant women at term, in their babies' cord blood samples, and blood specimens obtained from 43 infants aged 3-12 months. The concentration of ferritin was higher in cord serum than in respective maternal samples and infant specimens. Low values were found in more than half of the maternal venous samples. Iron stores of newborns delivered by mothers with low serum ferritin concentration were lower than in newborns of mothers having normal ferritin levels. Serum ferritin measurement is a sensitive method to determine iron deficiency in pregnancy.