Determinants of Neonatal Iron Homeostasis in Women Carrying Multiples

Multiple births in the United States are rapidly increasing in large part due to assisted reproductive technologies. Recent data indicate that multiple births now comprise 3-4.5% of all births in the United States. Pregnant women are at risk for iron (Fe) deficiency anemia yet there are virtually no data on Fe status in women carrying multiples and current recommendations do not necessitate Fe screening among this high risk group. Maternal anemia is known to increase the risk of adverse birth outcomes including preterm birth and low birth weight. Moreover, the developing brain is increasingly recognized to be susceptible to Fe insufficiency in utero and growing data support that suboptimal Fe stores at birth are associated with long-term irreversible cognitive deficits in the offspring. To address these gaps in knowledge the investigators will monitor weight gain, hematological measures, Fe status indicators and serum hepcidin across pregnancy in approximately 120 women carrying twins and triplets. Determinants of maternal anemia will be identified. Neonatal hematological measures will be assessed in cord blood from each neonate at birth for assessment of hematological measures, Fe status and hepcidin. Determinants of neonatal anemia will be identified. Inflammatory markers will be measured in all blood samples and related to outcomes. Stable iron isotopes will be given to a subset of women to assess maternal Fe absorption and fetal Fe uptake.