Prenatal Iron Deficiency and Replete Iron Status Are Associated with Adverse Birth Outcomes, but Associations Differ in Ghana and Malawi

Background Previous literature suggests a U-shaped relation between hemoglobin concentration and adverse birth outcomes. There is less evidence on associations between iron status and birth outcomes. Objective Our objective was to determine the associations of maternal hemoglobin concentration and iron status with birth outcomes. Methods We conducted a secondary data analysis of data from 2 cohorts of pregnant women receiving iron-containing nutritional supplements (20–60 mg ferrous sulfate) in Ghana (n = 1137) and Malawi (n = 1243). Hemoglobin concentration and 2 markers of iron status [zinc protoporphyrin and soluble transferrin receptor (sTfR)] were measured at ≤20 weeks and 36 weeks of gestation. We used linear and Poisson regression models and birth outcomes included preterm birth (PTB), newborn stunting, low birth weight (LBW), and small-for-gestational-age. Results Prevalence of iron deficiency (sTfR \u3e6.0 mg/L) at enrollment was 9% in Ghana and 20% in Malawi. In early pregnancy, iron deficiency was associated with PTB (9% compared with 17%, adjusted RR: 1.63; 95% CI: 1.14, 2.33) and stunting (15% compared with 23%, adjusted RR: 1.44; 95% CI: 1.09, 1.94) in Malawi but not Ghana, and was not associated with LBW in either country; replete iron status (sTfR \u3c10th \u3epercentile) was associated with stunting (9% compared with 15%, adjusted RR: 1.71; 95% CI: 1.06, 2.77) in Ghana, but not PTB or LBW, and was not associated with any birth outcomes in Malawi. In late pregnancy, iron deficiency was not related to birth outcomes in either country and iron-replete status was associated with higher risk of LBW (8% compared with 16%, adjusted RR: 1.90; 95% CI: 1.17, 3.09) and stunting (6% compared with 13%, adjusted RR: 2.14; 95% CI: 1.21, 3.77) in Ghana, but was not associated with birth outcomes in Malawi. Conclusions The associations of low or replete iron status with birth outcomes are population specific. Research to replicate and extend these findings would be beneficial. These trials were registered at clinicaltrials.gov as NCT00970866 (Ghana) and NCT01239693 (Malawi)

Long-chain polyunsaturated fatty acid requirements during pregnancy and lactation

Much interest has been expressed about the long-chain polyunsaturated fatty acid (LCPUFA) requirements of both preterm and term infants, whereas relatively little attention has been given to the LCPUFA needs of mothers, who may provide the primary source of LCPUFAs for their fetuses and breast-fed infants. Although maternal requirements for LCPUFAs are difficult to estimate because of large body stores and the capacity to synthesize LCPUFAs from precursors, biochemical and clinical intervention studies have provided some clues. From a biochemical viewpoint, there appears to be no detectable reduction in plasma n-3 LCPUFA concentrations during pregnancy, whereas there is a clear decline during the early postpartum period. The postpartum decrease in maternal plasma docosahexaenoic acid (DHA) concentration is not instantaneous, may be long-term, is independent of lactation, and is reversible with dietary DHA supplementation (200-400 mg/d). From a functional standpoint, the results of randomized clinical studies suggest that n-3 LCPUFA supplementation during pregnancy does not affect the incidences of pregnancy-induced hypertension and preeclampsia without edema. However, n-3 LCPUFA supplementation may cause modest increases in the duration of gestation, birth weight, or both. To date, there is little evidence of harm as a result of n-3 LCPUFA supplementation during either pregnancy or lactation. However, researchers need to further elucidate any potential benefits of supplementation for mothers and infants. Careful attention should be paid to study design, measurement of appropriate health outcomes, and defining minimum and maximum plasma n-3 LCPUFA concentrations that are optimal for both mothers and infants.Maria Makrides and Robert A. Gibso