The interplay between maternal-infant anemia and iron deficiency

Physiologically based trimester-specific serum ferritin thresholds for iron deficiency in US pregnant women

ABSTRACT

Serum ferritin (SF) concentration is the most widely used indicator for iron deficiency (ID). During pregnancy, the World Health Organization recently recommended SF thresholds for ID of <15 μg/L for the first trimester of pregnancy, based on expert opinion, and made no recommendations for the second and third trimesters. We examined the relationship of SF with 2 independent indicators of the onset of iron-deficient erythropoiesis, hemoglobin and soluble transferrin receptor 1, in cross-sectional data from US National Health and Nutrition Examination Survey for 1999 to 2010 and 2015 to 2018. We included 1288 pregnant women aged 15 to 49 years and excluded women with inflammation or potential liver disease. We used restricted cubic spline (RCS) regression analysis to determine SF thresholds for iron-deficient erythropoiesis. SF decreased during pregnancy; geometric mean SF was higher during the first and lower during the second and third trimesters. Using RCS analysis, the SF thresholds identified during pregnancy were <25.8 μg/L (18.1-28.5) during first trimester, <18.3 μg/L (16.3-22.9) during second trimester, and <19.0 μg/L (14.4- 26.1) during third trimester. These SF threshold levels track concentrations of hepcidin, the iron-regulatory hormone controlling the mobilization of iron stores. An SF concentration of <15 μg/L as the criterion for ID may underestimate the true prevalence of ID throughout pregnancy. In our study, an additional 1 of every 10 pregnant women would be recognized as iron deficient by using the physiologically based thresholds at SF of ∼25 μg/L during the first and ∼20 μg/L during the second and third trimesters.

Birth weight mediates the association of maternal undernutrition with child undernutrition prevalence in West Africa

BACKGROUND

Maternal nutritional status before and during pregnancy is an important determinant of foetal health. In West Africa, maternal and child undernutrition remains a major public health problem and it is important to establish the mechanistic pathway linking the two disorders to help address the problem. We therefore assessed the mediating role of low birth weight (LBW) in the relationship of maternal undernutrition with child undernutrition in West Africa.

METHODS

We included recent (2010-2019) DHS data from thirteen West African countries. Poisson regression model with robust standard errors was used to assess the relationship between maternal undernutrition (body mass index and anaemia) and child undernutrition (stunting, wasting, underweight, and anaemia). Structural equation modelling was used to conduct the mediation analysis.

RESULTS

Prevalence of stunting, wasting, underweight, and anaemia among under-five children in West Africa was found to be 32.4%, 8.1%, 20.1%, and 71.5%, respectively. We found children of underweight mothers to be more likely to be undernourished (stunted, wasted, and underweight) and anaemic compared to children of normal-weight mothers. Also, children of anaemic mothers were more likely to be stunted and anaemic but not wasted compared with children of non-anaemic mothers. LBW mediated the observed relationships between maternal BMI and childhood stunting (22.6%), and maternal anaemia and childhood stunting (24.9%), wasting (11.7), and anaemia (6.6%).

CONCLUSION

We found maternal undernutrition to be associated with child undernutrition in West Africa with LBW noted to be a mediator of the observed relationship. We recommend that, to address the child undernutrition problem in West Africa, governments and policymakers must integrate measures to address the burden of LBW.

Sex-specific association between maternal mild anemia and children's behavioral development: a birth cohort study

There has been limited research on maternal anemia affecting children's behavioral development, with a lack of studies focusing on sex differences in this association. Based on the Ma'anshan Birth Cohort, 2132 mother-child pairs were included. Maternal anemia was evaluated based on the hemoglobin concentration and children's behavioral development was assessed by Achenbach Child Behavior Checklist 1.5-5. Binary logistic regression models indicated that compared with children born of mothers without anemia throughout pregnancy, maternal mild anemia during pregnancy or only anemia in the 3rd trimester was associated with increased risks of aggressive behaviors in boys. Maternal mild anemia only in the 2nd trimester was associated with increased risks of attention problems in boys. In girls, maternal mild anemia during pregnancy was associated with increased risks of withdrawn, internalizing problems and total problems. Girls born of mothers with mild anemia only in the 2nd trimester had higher risks of total problems. Maternal mild anemia in both 2nd and 3rd trimesters was associated with increased risks of internalizing problems in girls. Our study identified sex-specific effects of maternal mild anemia during pregnancy on children's behavioral development problems.

Intracellular Regulation Limits the Response of Intestinal Ferroportin to Iron Status in Suckling Rats

SCOPE

Iron status is regulated via iron absorption as there is no active iron excretion. Divalent metal-ion transporter-1 (DMT1) and ferroportin (FPN) are two key proteins vital for iron absorption, but the regulation of them in suckling mammals differs from that in adults. This study aims to explore regulation of iron transporters under different iron conditions during suckling.

METHODS AND RESULTS

This study developed suckling rats under different iron conditions. Unexpectedly, unchanged FPN at different iron status are detected. Since FPN is the only known iron exporter for mammals, unchanged FPN limits iron exported into blood during suckling. Thus, factors regulating FPN at transcriptional, post-transcriptional, and post-translational levels are detected. Results showed that Fpn mRNA is upregulated, while micro RNA-485(miR-485) which could silence Fpn mRNA is upregulated at low iron status limiting translation of Fpn mRNA. Besides, serum hepcidin and liver Hamp mRNA are upregulated, but ring finger protein 217( Rnf217) mRNA remained unchanged at high iron status leading to FPN not downregulated as adults.

CONCLUSIONS

Overall, this study indicates that translational regulation limits intestinal FPN protein response to iron deficiency and Rnf217 cannot effectively mediate the degradation of FPN at high iron status, which provides a reference for maintaining iron homeostasis during suckling.

Prevalence and correlates of childhood anemia in the MINA-Brazil birth cohort study

OBJECTIVE

This study aimed to describe the prevalence and predictors of childhood anemia in an Amazonian population-based birth cohort study.

METHODS

Prevalence of maternal anemia was estimated at delivery (hemoglobin [Hb] concentration < 110 g/L) in women participating in the MINA-Brazil birth cohort study and in their children, examined at ages one, two (Hb < 110 g/L), and five (Hb < 115 g/L). Moreover, ferritin, soluble transferrin receptor, and C-reactive protein concentrations were measured in mothers at delivery and in their 1- and 2-year-old children to estimate the prevalence of iron deficiency and its contribution to anemia, while adjusting for potential confounders by multiple Poisson regression analysis (adjusted relative risk [RRa]).

RESULTS

The prevalence 95% confidence interval (CI) of maternal anemia, iron deficiency, and iron-deficiency anemia at delivery were 17.3% (14.0-21.0%), 42.6% (38.0-47.2%), and 8.7% (6.3-11.6)%, respectively (n = 462). At one year of age (n = 646), 42.2% (38.7-45.8%) of the study children were anemic, 38.4% (34.6-42.3%) were iron-deficient, and 26.3 (23.0-29.9) had iron-deficiency anemia. At two years of age (n = 761), these values decreased to 12.8% (10.6-15.2%), 18.1% (15.5-21.1%), and 4.1% (2.8-5.7%), respectively; at five years of age (n = 655), 5.2% (3.6-7.2%) were anemic. Iron deficiency (RRa = 2.19; 95%CI: 1.84-2.60) and consumption of ultra-processed foods (UPF) (RRa = 1.56; 95%CI: 1.14-2.13) were significant contributors to anemia at 1 year, after adjusting for maternal schooling. At 2 years, anemia was significantly associated with maternal anemia at delivery (RRa: 1.67; 95%CI: 1.17-2.39), malaria since birth (2.25; 1.30-3.87), and iron deficiency (2.15; 1.47-3.15), after adjusting for children's age and household wealth index.

CONCLUSIONS

Anemia continues to be highly prevalent during pregnancy and early childhood in the Amazon. Public health policies should address iron deficiency, UPF intake, maternal anemia, and malaria to prevent and treat anemia in Amazonian children.

Ferrous-sucrose complex supplementation regulates maternal plasma metabolism and the fecal microbiota composition and improves neonatal immunity and placental glucose transportation by activating the EGF/PI3K/AKT signaling pathways in sows

Pregnancy is a dynamic state involving rapid physiological changes in metabolism, affecting the health and development of the offspring. During pregnancy, the placenta constitutes a physical and immunological barrier to provide fetal nutrition through the maternal blood and prevent the exposure of the fetus to dangerous signals. Metabolic changes in the plasma, the fecal microbiota profile, and functional regulation in the placenta were studied in sows supplied with a ferrous-sucrose complex (FeSuc) from late gestation to parturition. The results revealed that maternal FeSuc supplementation enhanced arginine and proline metabolism, glutathione metabolism, with increased glutamic acid, beta-D-glucosamine, L-proline, 1-butylamine, and succinic acid and reduced sphingosine and chenodeoxycholic acid sulfate levels in the plasma. Moreover, significantly increased abundances of Christensenellaceae_R-7_group, Prevotellaceae_NK3B31_group, and Lachnospiraceae_NK4B4_group were detected in the feces of sows from the FeSuc group (P < 0.05). Spearman's correlation analysis indicated that Prevotellaceae_NK3B31_group abundances were positively correlated with glutamic acid, indoxyl sulfate, acetyl-DL-leucine, and beta-D-glucosamine, while Christensenellaceae_R-7_group was positively correlated with beta-D-glucosamine. Furthermore, maternal FeSuc supplementation significantly increased neonatal glucose (P < 0.01) and iron (P < 0.01) in the neonatal serum, significantly increased IL-10 and TGF-β1 levels in the neonatal liver (P < 0.01) and jejunum (P < 0.05), promoted the transcription of immune molecules in the placenta, and significantly increased the protein expressions of EGF (P < 0.05), PI3K (P < 0.01), p-PI3K (P < 0.001), p-AKT (P < 0.01), and glucose transporter 1 (GLUT1) (P < 0.001) in the placenta. The current study demonstrated that FeSuc supplementation regulated maternal metabolism processes by altering the fecal microbial composition and improved neonatal immunity and placental glucose transportation by activating the EGF/PI3K/AKT signaling pathways in sows.