Serum Ferritin as a Measure of Iron Stores During and After Normal Pregnancy with and Without Iron Supplements

Abstract

The iron stores of 32 healthy pregnant women were evaluated longitudinally during pregnancy and 6 months post partum by serum ferritin assay and by bone marrow iron content. Half of the women were receiving oral iron while the others were not given iron supplementation.Women receiving iron could maintain their iron stores throughout the pregnancy. By contrast, women without iron therapy had low serum ferritin values, pointing to the absence of iron stores during the last trimester, and 6 of these 16 women developed anemia. This was confirmed by estimation of the quantity of stainable iron in the bone marrow. In addition serum iron, transferrin and red cell MCV values indicated iron deficient erythropoesis.During a 6-month period after pregnancy the women receiving supplemental iron during pregnancy had a significant increase in their serum ferritin concentrations, indicating restoration of iron stores.Women not receiving iron during pregnancy had exhausted iron stores at term and serum ferritin values stayed low even at 6 months after delivery. If iron therapy was instituted after parturition, serum ferritin assays indicated restoration of iron stores within the ensuing 6 month. To prevent iron deficiency anemia during pregnancy supplemental iron is advisable for all pregnant women in our country.

Prevalence of iron deficiency and anemia among healthy women of reproductive age in Bhaktapur, Nepal

“…Evidence from randomized control trials indicates that iron supplementation decreases the incidence of iron-deficiency anemia during pregnancy (10,(39)(40)(41)(42), but trials of the effect of universal iron supplementation during pregnancy on adverse maternal and infant outcomes are inconclusive (10,43,44 ).…”

“…Among pregnant women, Hb concentration and Hct decline during the first and second trimesters because of an expanding blood volume (18,(39)(40)(41)(42). Among pregnant women who do not take iron supplements, Hb concentration and Hct remain low in the third trimester, and among pregnant women who have adequate iron intake, Hb concentration and Hct gradually rise during the third trimester toward the prepregnancy levels (39,40 ).…”

“…Among pregnant women who do not take iron supplements, Hb concentration and Hct remain low in the third trimester, and among pregnant women who have adequate iron intake, Hb concentration and Hct gradually rise during the third trimester toward the prepregnancy levels (39,40 ). Because adequate data are lacking in the United States, the cutoff values for anemia are based on clinical studies of European women who had taken iron supplementation during pregnancy (39)(40)(41)(42)72 ). For pregnant women, a test *Age-and sex-specific cutoff values for anemia are based on the 5th percentile from the third National Health and Nutrition Examination Survey (NHANES III), which excluded persons who had a high likelihood of iron deficiency by using the same methods described by Looker et al (45 ).…”

“…For pregnant women, a test *Age-and sex-specific cutoff values for anemia are based on the 5th percentile from the third National Health and Nutrition Examination Survey (NHANES III), which excluded persons who had a high likelihood of iron deficiency by using the same methods described by Looker et al (45 ). Maximum values for anemia during pregnancy are based on values from pregnant women who had adequate iron supplementation (39)(40)(41)(42)72 ). † Although no data are available from NHANES III to determine the maximum hemoglobin concentration and hematocrit values for anemia among infants, the values listed for children aged 1-<2 years can be used for infants aged 6-12 months.…”

“…Although iron-deficiency anemia during pregnancy is associated with preterm delivery and delivering a low-birthweight baby (38 ), well designed, randomized control trials are needed to evaluate the effectiveness of universal iron supplementation on mitigating adverse birth outcomes. Some studies have indicated that adequate iron supplementation during pregnancy reduces the prevalence of irondeficiency anemia (6,10,(39)(40)(41)(42)66,104 ), but over the last few decades, the recommendation by the Council on Foods and Nutrition and other groups to supplement iron intake during pregnancy has not resulted in a reduced prevalence of anemia among low-income, pregnant women (4,9,105 ). Evidence on iron supplement use is limited, however, so it is not known how well the recommendation has been followed.…”