Prenatal maternal stress predicts cord-blood ferritin concentration

Early life stress and iron metabolism in developmental psychoneuroimmunology

An estimated 250 million children face adverse health outcomes from early life exposure to severe or chronic social, economic, and nutritional adversity, highlighting/emphasizing the pressing concern about the link between ELS and long-term implications on mental and physical health. There is significant overlap between populations experiencing high levels of chronic stress and those experiencing iron deficiency, spotlighting the potential role of iron as a key mediator in this association. Iron, an essential micronutrient for brain development and immune function, is often depleted in stress conditions. Iron deficiency among the most common nutrient deficiencies in the world. Fetal and infant iron status may thus serve as a crucial intermediary between early chronic psychological stress and subsequent immune system changes to impact neurodevelopment. The review presents a hypothesized pathway between early life stress (ELS), iron deficiency, and neurodevelopment through the hypothalamic-pituitary-adrenocortical (HPA) axis and the IL-6-hepcidin axis. This hypothesis is derived from (1) evidence that stress impacts iron status (2) long-term neurodevelopmental outcomes that are shared by ELS and iron deficiency exposure, and (3) possible mechanisms for how iron may mediate the relation between ELS and iron deficiency through alterations in the developing immune system. The article concludes by proposing future research directions, emphasizing the need for rigorous studies to elucidate how stress and iron metabolism interact to modify the developing immune system. Understanding these mechanisms could open new avenues for improving human health and neurodevelopment for women and children globally, making it a timely and vital area of study in psychoneuroimmunology research.

Early-life adversity is associated with poor iron status in infancy

Exposure to early-life adversity (ELA) and iron deficiency early in life are known risk factors for suboptimal brain and socioemotional development. Iron deficiency may arise from and co-occur with ELA, which could negatively affect development. In the present study, we investigated whether ELA is associated with iron deficiency in infants receiving no iron supplementation. This study is a secondary analysis of extant data collected in the 1990s; participants were healthy infants from working-class communities in Santiago, Chile (N = 534, 45.5% female). We measured stressful life events, maternal depression, and low home support for child development during infancy and assessed iron status when the infant was 12 months old. Slightly more than half of the infants were iron-deficient (51%), and 25.8% were iron-deficient anemic at 12 months. Results indicated that ELA was associated with lower iron levels and iron deficiency at 12 months. The findings are consistent with animal and human prenatal models of stress and iron status and provide evidence of the association between postnatal ELA and iron status in humans. The findings also highlight a nutritional pathway by which ELA may impact development and present a nutritionally-focused avenue for future research on ELA and psychopathology.

The Interaction between Psychological Stress and Iron Status on Early-Life Neurodevelopmental Outcomes

This review presents evidence from animal and human studies demonstrating the possible connection and significant impact of poor iron status and psychological distress on neurocognitive development during pregnancy and the neonatal period, with implications for long-term cognition. Stress and iron deficiency are independently prevalent and thus are frequently comorbid. While iron deficiency and early-life stress independently contribute to long-term neurodevelopmental alterations, their combined effects remain underexplored. Psychological stress responses may engage similar pathways as infectious stress, which alters fundamental iron metabolism processes and cause functional tissue-level iron deficiency. Psychological stress, analogous to but to a lesser degree than infectious stress, activates the hypothalamic-pituitary-adrenocortical (HPA) axis and increases proinflammatory cytokines. Chronic or severe stress is associated with dysregulated HPA axis functioning and a proinflammatory state. This dysregulation may disrupt iron absorption and utilization, likely mediated by the IL-6 activation of hepcidin, a molecule that impedes iron absorption and redistributes total body iron. This narrative review highlights suggestive studies investigating the relationship between psychological stress and iron status and outlines hypothesized mechanistic pathways connecting psychological stress exposure and iron metabolism. We examine findings regarding the overlapping impacts of early stress exposure to iron deficiency and children's neurocognitive development. We propose that studying the influence of psychological stress on iron metabolism is crucial for comprehending neurocognitive development in children exposed to prenatal and early postnatal stressors and for children at risk of early iron insufficiency. We recommend future directions for dual-exposure studies exploring iron as a potential mediating pathway between early stress and offspring neurodevelopment, offering opportunities for targeted interventions.

Prenatal stress perturbs fetal iron homeostasis in a sex specific manner

The adverse effects of maternal prenatal stress (PS) on child's neurodevelopment warrant the establishment of biomarkers that enable early interventional therapeutic strategies. We performed a prospective matched double cohort study screening 2000 pregnant women in third trimester with Cohen Perceived Stress Scale-10 (PSS-10) questionnaire; 164 participants were recruited and classified as stressed and control group (SG, CG). Fetal cord blood iron parameters of 107 patients were measured at birth. Transabdominal electrocardiograms-based Fetal Stress Index (FSI) was derived. We investigated sex contribution to group differences and conducted causal inference analyses to assess the total effect of PS exposure on iron homeostasis using a directed acyclic graph (DAG) approach. Differences are reported for p < 0.05 unless noted otherwise. Transferrin saturation was lower in male stressed neonates. The minimum adjustment set of the DAG to estimate the total effect of PS exposure on fetal ferritin iron biomarkers consisted of maternal age and socioeconomic status: SG revealed a 15% decrease in fetal ferritin compared with CG. Mean FSI was higher among SG than among CG. FSI-based timely detection of fetuses affected by PS can support early individualized iron supplementation and neurodevelopmental follow-up to prevent long-term sequelae due to PS-exacerbated impairment of the iron homeostasis.

Maternal Prenatal Psychosocial Stress and Prepregnancy BMI Associations with Fetal Iron Status

BACKGROUND

Iron accrued in utero is critical for fetal and infant neurocognitive development. Psychosocial stress and obesity can each suppress fetal iron accrual. Their combined effects and differences by fetal sex are not known. In an observational pregnancy cohort study in Mexico City, we investigated associations of maternal prenatal life stressors, psychological dysfunction, and prepregnancy BMI with fetal iron status at delivery.

OBJECTIVES

We hypothesized that greater maternal prenatal psychosocial stress and prepregnancy overweight and obesity are associated with lower cord blood ferritin and hemoglobin (Hb), with stronger associations in boys than girls.

METHODS

Psychosocial stress in multiple domains of life stress (negative life events, perceived stress, exposure to violence) and psychological dysfunction symptoms (depression, generalized anxiety, and pregnancy-specific anxiety) were assessed with validated questionnaires during pregnancy. Prepregnancy BMI was predicted with a validated equation and categorized as normal/overweight/obese. Cord blood ferritin and Hb associations with prenatal psychosocial stress and BMI were modeled in multivariable linear regressions adjusted for maternal age, socioeconomic status, child sex, and prenatal iron supplementation. Interactions with child sex and 3-way stress-overweight/obesity-sex interactions were tested with product terms and likelihood ratio tests.

RESULTS

In 493 dyads, median (IQR) cord blood ferritin and Hb concentrations were 185 µg/L (126-263 g/dL) and 16 g/dL (14.7-17.1 g/dL), respectively. Ferritin was lower in infants of mothers with higher prenatal perceived stress (-23%; 95% CI: -35%, -9%), violence exposure (-28%; 95% CI: -42%, -12%), anxiety symptoms (-16%; 95% CI: -27%, -4%), and obesity (-17%; 95% CI: -31%, 0.2%). Interaction models suggested sex differences and synergism between maternal stress and overweight/obesity. No associations were observed between stress or BMI and Hb.

CONCLUSIONS

Multiple prenatal psychosocial stressors and excess prepregnancy BMI were each inversely associated with fetal iron status at birth. Pregnancies and infants at elevated risk of impaired fetal iron accrual may be identifiable according to observed synergism between maternal stress and obesity and differential associations with fetal iron status by infant sex.

Maternal Perceived Stress during Pregnancy Increases Risk for Low Neonatal Iron at Delivery and Depletion of Storage Iron at One Year

OBJECTIVE

To investigate the impact of maternal stress during pregnancy on newborn iron and stage 1 iron deficiency at 1 year of age.

STUDY DESIGN

In total, 245 mothers and their newborn infants (52% male; 72% white) were recruited at the Meriter Hospital Birthing Center on the basis of known risk factors for iron deficiency. Umbilical cord blood hemoglobin and zinc protoporphyrin/heme (ZnPP/H) were determined to evaluate erythrocyte iron and plasma ferritin was determined to reflect storage iron. Mothers retrospectively reported stress experienced previously during pregnancy on a 25-item questionnaire. Blood was also was collected from 79 infants who were breastfed at 1 year of age.

RESULTS

Maternal recall of distress and health concerns during pregnancy correlated with cord blood ZnPP/H indices (r = 0.21, P < .01), even in the absence of major traumatic events. When concurrent with other known risks for iron deficiency, including maternal adiposity, socioeconomic status, and race, maternal stress had a summative effect, lowering cord blood iron. At 1 year, 24% of infants who were breastfed had moderate iron deficiency (plasma ferritin <12 µg/L). Higher cord blood ZnPP/H was predictive of this moderate iron deficiency (95% CI 0.26-1.47, P = .007). When coincident with maternal reports of gestational stress, the likelihood of low plasma ferritin at 1 year increased 36-fold in breastfed infants as compared with low-stress pregnancies (95% CI 1.33-6.83, P = .007).

CONCLUSIONS

Maternal recall of stress during pregnancy was associated with lower iron stores at birth. High cord blood ZnPP/H, reflecting low erythrocyte iron, was correlated with the likelihood of stage 1 iron deficiency at 1 year, when rapid growth can deplete storage iron in breastfed infants.

Maternal iron nutriture as a critical modulator of fetal alcohol spectrum disorder risk in alcohol-exposed pregnancies

Alcohol consumption during pregnancy places the fetus at risk for permanent physical, cognitive, and behavioral impairments, collectively termed fetal alcohol spectrum disorder (FASD). However, prenatal alcohol exposure (PAE) outcomes vary widely, and growing evidence suggests that maternal nutrition is a modifying factor. Certain nutrients, such as iron, may modulate FASD outcomes. Untreated gestational iron deficiency (ID) causes persistent neurodevelopmental deficits in the offspring that affect many of the same domains damaged by PAE. Although chronic alcohol consumption enhances iron uptake and elevates liver iron stores in adult alcoholics, alcohol-abusing premenopausal women often have low iron reserves due to menstruation, childbirth, and poor diet. Recent investigations show that low iron reserves during pregnancy are strongly associated with a worsening of several hallmark features in FASD including reduced growth and impaired associative learning. This review discusses recent clinical and animal model findings that maternal ID worsens fetal outcomes in response to PAE. It also discusses underlying mechanisms by which PAE disrupts maternal and fetal iron homeostasis. We suggest that alcohol-exposed ID pregnancies contribute to the severe end of the FASD spectrum.

Data collection tools for maternal and child health in humanitarian emergencies: a systematic review

OBJECTIVE

To describe tools used for the assessment of maternal and child health issues in humanitarian emergency settings.

METHODS

We systematically searched MEDLINE, Web of Knowledge and POPLINE databases for studies published between January 2000 and June 2014. We also searched the websites of organizations active in humanitarian emergencies. We included studies reporting the development or use of data collection tools concerning the health of women and children in humanitarian emergencies. We used narrative synthesis to summarize the studies.

FINDINGS

We identified 100 studies: 80 reported on conflict situations and 20 followed natural disasters. Most studies (76/100) focused on the health status of the affected population while 24 focused on the availability and coverage of health services. Of 17 different data collection tools identified, 14 focused on sexual and reproductive health, nine concerned maternal, newborn and child health and four were used to collect information on sexual or gender-based violence. Sixty-nine studies were done for monitoring and evaluation purposes, 18 for advocacy, seven for operational research and six for needs assessment.

CONCLUSION

Practical and effective means of data collection are needed to inform life-saving actions in humanitarian emergencies. There are a wide variety of tools available, not all of which have been used in the field. A simplified, standardized tool should be developed for assessment of health issues in the early stages of humanitarian emergencies. A cluster approach is recommended, in partnership with operational researchers and humanitarian agencies, coordinated by the World Health Organization.

Exposure to the Chinese famine in early life and the risk of anaemia in adulthood

Background

Famine exposure during the early stage of life is related to a number of adulthood diseases. The objective of this study was to examine the association of early life exposure to the famine in China (1959–1961) with the risk of anaemia in adulthood.

Methods

We used the data of 2007 adults born between 1954 and 1964 in Jiangsu province from the 2002 Chinese National Nutrition and Health Survey. Anaemia was defined as haemoglobin concentration <12 g/dl in women and <13 g/dl in men.

Results

Prevalence of anaemia in adulthood in nonexposed, fetal-exposed, early-childhood, mid-childhood, and late-childhood exposed to famine groups were 26.0%, 33.8%, 28.1%, 28.2% and 29.7%, respectively. Overall, fetal-exposed to famine was associated with 37% increased risk of anaemia as compared with those non-exposed after adjusting for income, education, place of residence, smoking, alcohol drinking, job, hypertension and BMI; relative risk (95% confidence interval) (RR (95% CI)) was 1.37 (1.09, 1.71). In general, this association appeared to be stronger among men, those who were currently overweight or obese, or those of lower educational levels. Corresponding RR (95% CI) was 1.87 (1.21-2.87), 1.75 (1.20-2.56), and 2.07 (1.37-3.12), respectively.

Conclusions

Fetal exposure to the Chinese famine was associated with an increased risk of anaemia in adulthood.