BACKGROUND Anemia in pregnancy is common worldwide and has known maternal risks. The relationship between the types of treatment offered for maternal anemia and the effects on the fetus and newborn are largely uninvestigated. OBJECTIVE Investigate whether maternal treatment with intravenous ferumoxytol compared to oral ferrous sulfate results in an increase in neonatal hematologic and iron indices. These analyses were
planned secondary outcomes and post-hoc analysis from the trial with a primary outcome of change in maternal hemoglobin. STUDY DESIGN A randomized controlled trial including 124 participants with anemia by WHO criteria was performed in which participants were allocated in a 1:1 ratio to either 2 infusions of 510mg of intravenous ferumoxytol or 325mg oral ferrous sulfate twice daily. Fetal monitoring was performed during each intravenous iron infusion. Standard univariable statistical techniques were used to compare groups and to investigate associations between maternal and neonatal hemoglobin and iron indices. RESULTS Cord blood hematological parameters were equivalent between groups. Hemoglobin was 15.7g/dL vs 15.4g/dL (p = 0.6) and hematocrit was 50.5% and 49.2% (p=0.4) in those randomized to intravenous ferumoxytol, and oral ferrous sulfate, respectively. Iron studies revealed higher cord blood ferritin concentrations in infants of participants treated with intravenous ferumoxytol (294 vs 186, p = 0.005). There were equivalent iron (158 vs 146, p = 0.4), transferrin (186 vs 196, p=0.4) and total iron binding capacity (246 vs 244, p=1) in neonates of participants receiving intravenous versus oral treatment. There were no effects of the infusions observed on cardiotocography. Gestational age at birth was equivalent between groups. We noted a larger birth weight in neonates of participants treated with intravenous ferumoxytol (3215g vs 3033g, p=0.09), which was not statistically significant. Post hoc analyses revealed a statistically significant correlation between neonatal ferritin and maternal hemoglobin (p=0.006) and neonatal ferritin and maternal ferritin (p=0.017) at admission for delivery. CONCLUSION Neonates born to participants who received intravenous ferumoxytol were born with higher ferritin concentrations in cord blood, at the same gestation with the same birthweight. Participants with higher hemoglobin and ferritin indices delivered infants with higher ferritin concentrations in cord blood.