Effect of oral iron supplementation during pregnancy on maternal and fetal iron status.

The known increased need for iron during pregnancy appears to be met only in part by increased iron absorption and amenorrhea. Considerable demands are made on maternal iron stores and, since many women lack sufficient storage iron, pregnancy may be expected to cause iron deficiency. This may lead to anemia in pregnancy and post partum and could also have a bearing on the iron status of the fetus and the neonate. Based on these considerations, prophylactic supplementation of dietary iron is advocated but remains a disputed issue. In the present controlled, prospective and longitudinal study changes in hematologic status, and in particular in iron stores, during pregnancy were investigated in 44 healthy Caucasian women with uncomplicated pregnancies and deliveries. They were randomly assigned to a study group (n = 21) receiving oral iron supplements from the 16th week of amenorrhea until 6 weeks post partum, and a control group (n = 23) without iron supplementation. Maternal concentrations of hemoglobin, serum iron, serum transferrin and serum ferritin were determined at 16, 28 and 36 weeks of amenorrhea, at delivery, and 6 and 12 weeks post partum. The same variables were determined in cord blood. Iron supplementation appeared to prevent the physiologic fall in hemoglobin and serum iron concentrations which occurred in the control group, but had little influence on the observed rise in transferrin concentrations. Ferritin levels in serum, which are known to reflect mobilisable iron stores, fell to 30% of the initial values in the control group and to 70% in the study group. Six and 12 weeks post partum ferritin levels were still low in the nonsupplemented group (Tab. I).(ABSTRACT TRUNCATED AT 250 WORDS)