The Effect of Low Dose Iron and Zinc Intake on Child Micronutrient Status and Development during the First 1000 Days of Life: A Systematic Review and Meta-Analysis.

Adequate supply of micronutrients during the first 1000 days is essential for normal development and healthy life. We aimed to investigate if interventions administering dietary doses up to the recommended nutrient intake (RNI) of iron and zinc within the window from conception to age 2 years have the potential to influence nutritional status and development of children. To address this objective, a systematic review and meta-analysis of randomized and quasi-randomized fortification, biofortification, and supplementation trials in women (pregnant and lactating) and children (6-23 months) delivering iron or zinc in doses up to the recommended nutrient intake (RNI) levels was conducted. Supplying iron or zinc during pregnancy had no effects on birth outcomes. There were limited or no data on the effects of iron/zinc during pregnancy and lactation on child iron/zinc status, growth, morbidity, and psychomotor and mental development. Delivering up to 15 mg iron/day during infancy increased mean hemoglobin by 4 g/L (p < 0.001) and mean serum ferritin concentration by 17.6 µg/L (p < 0.001) and reduced the risk for anemia by 41% (p < 0.001), iron deficiency by 78% (ID; p < 0.001) and iron deficiency anemia by 80% (IDA; p < 0.001), but had no effect on growth or psychomotor development. Providing up to 10 mg of additional zinc during infancy increased plasma zinc concentration by 2.03 µmol/L (p < 0.001) and reduced the risk of zinc deficiency by 47% (p < 0.001). Further, we observed positive effects on child weight for age z-score (WAZ) (p < 0.05), weight for height z-score (WHZ) (p < 0.05), but not on height for age z-score (HAZ) or the risk for stunting, wasting, and underweight. There are no studies covering the full 1000 days window and the effects of iron and zinc delivered during pregnancy and lactation on child outcomes are ambiguous, but low dose daily iron and zinc use during 6-23 months of age has a positive effect on child iron and zinc status.

The Proportion of Anemia Associated with Iron Deficiency in Low, Medium, and High Human Development Index Countries: A Systematic Analysis of National Surveys.

Iron deficiency is commonly assumed to cause half of all cases of anemias, with hereditary blood disorders and infections such as hookworm and malaria being the other major causes. In countries ranked as low, medium, and high by the Human Development Index, we conducted a systematic review of nationally representative surveys that reported the prevalence of iron deficiency, iron deficiency anemia, and anemia among pre-school children and non-pregnant women of reproductive age. Using random effects meta-analyses techniques, data from 23 countries for pre-school children and non-pregnant women of reproductive age was pooled, and the proportion of anemia attributable to iron deficiency was estimated by region, inflammation exposure, anemia prevalence, and urban/rural setting. For pre-school children and non-pregnant women of reproductive age, the proportion of anemia associated with iron deficiency was 25.0% (95% CI: 18.0, 32.0) and 37.0% (95% CI: 28.0, 46.0), respectively. The proportion of anemia associated with iron deficiency was lower in countries where anemia prevalence was >40%, especially in rural populations (14% for pre-school children; 16% for non-pregnant women of reproductive age), and in countries with very high inflammation exposure (20% for pre-school children; 25% for non-pregnant women of reproductive age). Despite large heterogeneity, our analyses suggest that the proportion of anemia associated with iron deficiency is lower than the previously assumed 50% in countries with low, medium, or high Human Development Index ranking. Anemia-reduction strategies and programs should be based on an analysis of country-specific data, as iron deficiency may not always be the key determinant of anemia.

Fatores associados ao obito neonatal de recem-nascidos de alto risco: estudo multicentrico em Unidades Neonatais de Alto Risco no Nordeste brasileiro / Factors associated with neonatal death in high-risk infants: a multicenter study in High-Risk Neonatal Units in Northeast Brazil / Los factores asociados a la muerte neonatal de alto riesgo de recien nacidos: estudio multicentrico en Unidades Neonatales de Alto Riesgo en el noreste de Brasil

Este estudo pretendeu determinar os fatores associados à mortalidade intra-hospitalar, utilizando como variáveis explicativas as características individuais da mãe, da assistência ao pré-natal, parto e período neonatal e dos recém-nascidos internados em Unidades Neonatais de Alto Risco (UTIN) integrantes da Rede Norte-Nordeste de Saúde Perinatal no Nordeste do Brasil. Foi realizado estudo longitudinal, multicêntrico de base hospitalar. A população do estudo compreendeu 3.623 nascidos vivos internados em 34 UTIN. Após o ajuste para os três níveis hierárquicos do modelo de determinação do óbito em UTIN até o 27 o dia de vida, associaram-se: tipo de parto – cesariana (OR = 0,72; IC95%: 0,56-0,95); não uso de corticoide antenatal (OR = 1,51; IC95%: 1,01-2,25); pré-eclâmpsia (OR = 0,73; IC95%: 0,56-0,95); oligodramnia (OR = 1,57; IC95%: 1,17-2,10); peso ao nascer < 2.500g (OR = 1,40; IC95%: 1,03-1,90); escore de Apgar 5 o minuto < 7 (OR = 2,63; IC95%: 2,21-3,14); uso de tubo endotraqueal (OR = 1,95; IC95%: 1,31-2,91); não uso de surfactante (OR = 0,54; IC95%: 0,43-0,69). O óbito em UTIN é determinado pelas condições assistenciais à gestação, parto e recém-nato.

This study aimed to identify factors associated with in-hospital mortality in High-Risk Neonatal Units (NICU) belonging to the North-Northeast Perinatal Health Network in Northeast Brazil. The explanatory variables were individual maternal characteristics, prenatal care, childbirth and neonatal care, and infant characteristics. This was a longitudinal, multicenter hospital-based study. The study population consisted of 3,623 live born infants admitted to 34 NICUs. After adjusting for the three hierarchical levels in the model for determination of death in the NICU up to the 27 th day of life, the following showed statistically significant association: type of delivery – cesarean section (OR = 0.72; 95%CI: 0.56-0.95), non-use of prenatal steroids (OR =1.51; 95%CI: 1.01-2.25), preeclampsia (OR = 0.73; 95%CI: 0.56-0.95), oligohydramnios (OR = 1.57; 95%CI: 1, 17-2.10), birth weight < 2500g (OR = 1.40; 95%CI: 1.03-1.90), 5-minute Apgar score < 7 (OR = 2.63; 95%CI: 2.21-3.14), endotracheal intubation (OR = 1.95; 95%CI: 1.31-2.91), and non-use of surfactant (OR = 0.54; 95%CI: 0.43-0.69). Death during NICU care is determined by conditions of the pregnancy, childbirth, and the newborn.

Este estudio tuvo como objetivo determinar los factores asociados a la mortalidad hospitalaria, utilizando como variables explicativas las características individuales de la madre, la atención prenatal, el parto y los bebés recién nacidos internados en Unidades Neonatales de Alto Riesgo (UCIN), miembros de la red norte-noreste de salud perinatal en el noreste de Brasil. Fue realizado estudio longitudinal, multicéntrico basado en el hospital. La población de estudio incluyó 3.623 nacidos vivos admitidos en 34 UCIN. Después de ajustar los tres niveles jerárquicos para la determinación del modelo de muerte en la UCI neonatal hasta los 27 días de vida, se les asociaba un tipo de parto: cesárea (OR = 0,72; IC95%: 0,56-0,95); uso de corticosteroides prenatales (OR = 1,51; IC95%: 1,01-2,25); preeclampsia (OR = 0,73; IC95%: 0,56-0,95); oligohidramnios (OR = 1,57; IC95%: 1,17-2,10); peso al nacer < 2.500g (OR = 1.40; IC95%: 1,03-1,90); Apgar 5 minutos < 7 (OR = 2,63; IC95%: 2.21-3.14); intubación endotraqueal (OR = 1,95; IC95%: 1,31-2,91); uso de surfactante (OR = 0,54; IC95%: 0,43-0,69). La muerte durante el cuidado en una UCIN está determinada por las condiciones durante el embarazo, el parto y el recién nacido.

Anaemia, prenatal iron use, and risk of adverse pregnancy outcomes: systematic review and meta-analysis.

OBJECTIVES: To summarise evidence on the associations of maternal anaemia and prenatal iron use with maternal haematological and adverse pregnancy outcomes; and to evaluate potential exposure-response relations of dose of iron, duration of use, and haemoglobin concentration in prenatal period with pregnancy outcomes. DESIGN: Systematic review and meta-analysis DATA SOURCES: Searches of PubMed and Embase for studies published up to May 2012 and references of review articles. STUDY SELECTION CRITERIA: Randomised trials of prenatal iron use and prospective cohort studies of prenatal anaemia; cross sectional and case-control studies were excluded. RESULTS: 48 randomised trials (17 793 women) and 44 cohort studies (1 851 682 women) were included. Iron use increased maternal mean haemoglobin concentration by 4.59 (95% confidence interval 3.72 to 5.46) g/L compared with controls and significantly reduced the risk of anaemia (relative risk 0.50, 0.42 to 0.59), iron deficiency (0.59, 0.46 to 0.79), iron deficiency anaemia (0.40, 0.26 to 0.60), and low birth weight (0.81, 0.71 to 0.93). The effect of iron on preterm birth was not significant (relative risk 0.84, 0.68 to 1.03). Analysis of cohort studies showed a significantly higher risk of low birth weight (adjusted odds ratio 1.29, 1.09 to 1.53) and preterm birth (1.21, 1.13 to 1.30) with anaemia in the first or second trimester. Exposure-response analysis indicated that for every 10 mg increase in iron dose/day, up to 66 mg/day, the relative risk of maternal anaemia was 0.88 (0.84 to 0.92) (P for linear trend<0.001). Birth weight increased by 15.1 (6.0 to 24.2) g (P for linear trend=0.005) and risk of low birth weight decreased by 3% (relative risk 0.97, 0.95 to 0.98) for every 10 mg increase in dose/day (P for linear trend<0.001). Duration of use was not significantly associated with the outcomes after adjustment for dose. Furthermore, for each 1 g/L increase in mean haemoglobin, birth weight increased by 14.0 (6.8 to 21.8) g (P for linear trend=0.002); however, mean haemoglobin was not associated with the risk of low birth weight and preterm birth. No evidence of a significant effect on duration of gestation, small for gestational age births, and birth length was noted. CONCLUSIONS: Daily prenatal use of iron substantially improved birth weight in a linear dose-response fashion, probably leading to a reduction in risk of low birth weight. An improvement in prenatal mean haemoglobin concentration linearly increased birth weight.