Effects of iron supplementation to iron depleted and iron replete pregnant Danish women: Defining criteria for identification of women who can manage without supplements: A randomized, placebo-controlled study.

OBJECTIVE: To define criteria based on iron status parameters for the identification of healthy women who do need/do not need iron supplementation during normal pregnancy. METHODS: Randomized, double-blind, placebo-controlled study of 113 women (62 iron-, 51 placebo treated) and their newborns. Iron dose was 66 mg elemental iron as ferrous fumarate daily from 14-18 weeks gestation to delivery. Hemoglobin (Hb), serum (S)-ferritin, S-transferrin saturation percentage, and S-erythropoietin were measured during gestation, prepartum, one week and 8 weeks postpartum. The women were divided in groups according to S-ferritin levels at inclusion:<30,≥30,≥40,≥50 and≥60µg/L. Iron deficiency (ID) was defined as S-ferritin < 15µg/L; iron deficiency anemia (IDA) as S-ferritin < 15µg/L and Hb < 110 g/L. RESULTS: Placebo treated women with S-ferritin levels < 30µg/L at inclusion had a much higher incidence of ID/IDA than placebo treated women with S-ferritin levels≥30,≥40,≥50, and≥60µg/L. S-ferritin levels≥40µg/L were associated with a very low risk of ID/IDA and none of the women with levels≥50 and≥60µg/L displayed ID/IDA. CONCLUSIONS: Women having S-ferritin < 30µg/L in early pregnancy, have a high risk of ID/IDA and should be recommended ferrous iron supplements in appropriate doses. With increasing iron reserves, i.e., increasing S-ferritin, the need for iron supplements diminishes, and placebo treated women having S-ferritin ≥40µg/L seldom develop IDA. Women with S-ferritin levels≥50 and≥60µg/L or higher, have adequate iron reserves and do not need routine iron prophylaxis in pregnancy. The results support the arguments for an individual iron supplementation guided by iron status, to avoid unwanted side effects of unnecessary iron intake.

Iron supplementation in pregnant Danish women revisited: Effects on prepartum and postpartum iron deficiency, anemia, serum erythropoietin; including iron status, erythropoietin and anthropometrics in newborns. A randomized, placebo-controlled study.

OBJECTIVE: To assess effects of iron supplementation, 66 mg elemental iron daily as ferrous fumarate, on iron status markers during normal pregnancies. METHODS: Randomized, double-blind, placebo-controlled study of 119 women (62 iron-, 57 placebo -treated) and their newborns. Hemoglobin (Hb), serum (S)-ferritin, S-transferrin saturation percentage (TSAT) and S-erythropoietin (S-EPO) were measured at 14-18, 24-27 weeks of gestation, prepartum, 1 and 8 weeks postpartum. RESULT: From 24-27 weeks gestation to 8 weeks postpartum, the iron group had higher Hb, S-ferritin and TSAT than the placebo group; prepartum, 11% had iron deficiency (ID) and 0% iron deficiency anemia (IDA) in the iron group, vs 60% and 18% in the placebo group; 8 weeks postpartum 1.6% in the iron group had ID and 1.6% IDA vs 14% and 7% in the placebo group. S-EPO levels in the iron group were lower than in the placebo group (p < 0.001). Mothers prepartum S-EPO values were correlated to newborns cord S-EPO values (p < 0.001). Newborns to iron treated mothers had higher cord S-ferritin levels than those to placebo treated mothers (p = 0.02). Newborn girls had higher cord S-ferritin levels than boys (p < 0.01). There was no impact of iron supplementation on the length of gestation, placental weight, or newborns birth weight. Birth weight was correlated only with mothers' body weight, length of gestation and placental weight. CONCLUSION: Iron supplementation had a "positive" impact on iron status and Hb both during pregnancy and postpartum, with a low frequency of ID/IDA and also a "positive" influence on newborns iron status.