Impact Of Maternal Iron Status On Neonatal Iron Endowment And Functional Outcomes At Birth
Pregnant adolescents are at risk of anemia and iron deficiency (ID). Iron stores may be compromised in newborns born to women with ID, which is of concern given the importance of neonatal iron acquisition for neurodevelopment. This study was undertaken in 255 pregnant adolescents ([LESS-THAN OR EQUAL TO] 18 y) receiving prenatal care at the Rochester Adolescent Maternity Program (2006 - 2012). We characterized maternal dietary intake, prenatal supplement use; assessed maternal and neonatal iron status; and examined the impact of neonatal iron endowment on neurophysiological function at birth. Dietary intakes of iron, magnesium, calcium, vitamins D and E did not meet the EAR in more than 70% of teens surveyed, with calcium and magnesium being the nutrients with the greatest dietary deficits. Approximately half of the adolescents selfreported daily use of prenatal supplements, however the additional supplement contribution was insufficient to bridge the dietary deficit for the EAR for magnesium and calcium. From ~26 weeks gestation to delivery, the prevalence of maternal anemia (8.6% to 19%) and ID (sTfR > 8.5 mg/L; 7% to 14%) increased significantly. Elevated concentrations of ferritin and hepcidin were observed at delivery compared to mid-gestation, due to inflammation. Maternal EPO concentrations were significantly associated with indicators of maternal iron insufficiency and with low maternal hemoglobin concentration across pregnancy, and one benefit to this indicator was that EPO was not significantly associated with inflammation across gestation. Of concern, fully 1/4 of the newborns (n=193) were anemic or had low iron stores, respectively at birth. Of interest, cord ferritin did not significantly increase with gestational age across the final 6 weeks of pregnancy (37 - 42 weeks of gestation). Maternal iron stores impacted neonatal iron stores as neonates born to mothers with ferritin < 12 [MICRO SIGN]g/L had significantly lower ferritin compared to their counterparts. These findings speak to the need to examine the efficacy and optimal timing of maternal iron supplementation during pregnancy. No consistent relationships were evident between lower neonatal iron status and longer ABR peak latencies. Additional methods or functional approaches may be needed to fully capture the impact of neonatal iron status on neurodevelopment and other health outcomes.
Pregnant Adolescents; Neonatal Iron; Auditory Brainstem Response
O'Brien, Kimberly O
Robertson, Steven S; McDermid, Joann M.; Olson, Christine Marie
Ph.D. of Nutrition
Doctor of Philosophy
dissertation or thesis