Brain iron accumulation in unexplained fetal and infant death victims with smoker mothers--the possible involvement of maternal methemoglobinemia

Prenatal iron supplementation adjusted to maternal iron stores reduces behavioural problems in 4-year-old children

Prenatal iron supplementation improves children's health and cognitive performance, but few studies explore behavioural development. This study assessed the effects of adjusting prenatal iron supplementation to maternal iron stores during early pregnancy on children's behavioural problems. Randomized controlled trial conducted in Tarragona (Spain) involving 230 nonanaemic pregnant women and their children after a 4-year follow-up. Based on haemoglobin (Hb) levels before gestational week (GW) 12, women receive different iron doses: those with Hb = 110-130 g/L were randomized to receive 80 or 40 mg/day and those with Hb > 130 g/L were randomized to receive 20 or 40 mg/day. Maternal iron stores at GW12 were classified using serum ferritin (SF) as low (SF < 15 µg/L), normal (SF = 15-65 µg/L), and normal-high (SF > 65 µg/L). Children's behaviour was assessed by parents using the Child Behaviour Checklist for ages 1.5-5 years and the Behaviour Rating Inventory of Executive Function-Preschool Version, and by teachers using the Teacher's Report Form for ages 1.5-5 years. Multivariable regression models were performed. Taking 80 mg/day of iron improved child behaviour when women had low iron stores but worsened it when mothers had normal-high iron stores, except for depressive and attention/hyperactivity problems. Taking 20 mg/day of iron improved behaviour only in those children whose mothers had SF > 65 µg/L in early pregnancy. Additionally, executive functioning improved at high doses of prenatal iron when maternal baseline SF < 15 µg/L. Adjusting prenatal iron supplementation to both maternal baseline Hb levels and iron stores reduces behavioural problems in 4-year-old children.

Importance of Maternal Iron Status on the Improvement of Cognitive Function in Children After Prenatal Iron Supplementation

INTRODUCTION

The effectiveness of prenatal iron supplementation improves maternal hematological outcomes, but little research has focused on child outcomes. The objective of this study was to assess whether prenatal iron supplementation adjusted to maternal needs improves children's cognitive functioning.

METHODS

The analyses included a subsample of nonanemic pregnant women recruited in early pregnancy and their children aged 4 years (n=295). Data were collected between 2013 and 2017 in Tarragona (Spain). On the basis of hemoglobin levels before the 12th gestational week, women receive different iron doses: 80 vs 40 mg/d if hemoglobin is 110-130 g/L and 20 vs 40 mg/d if hemoglobin >130 g/L. Children's cognitive functioning was assessed using the Wechsler Preschool and Primary Scale of Intelligence-IV and Developmental Neuropsychological Assessment-II tests. The analyses were carried out in 2022 after the completion of the study. Multivariate regression models were performed for assessing the association between different doses of prenatal iron supplementation and children's cognitive functioning.

RESULTS

Taking 80 mg/d of iron was positively associated with all the scales of the Wechsler Preschool and Primary Scale of Intelligence-IV and Neuropsychological Assessment-II when mothers had initial serum ferritin <15 µg/L, but it was negatively associated with Verbal Comprehension Index, Working Memory Index, Processing Speed Index, and Vocabulary Acquisition Index from Wechsler Preschool and Primary Scale of Intelligence-IV and verbal fluency index from Neuropsychological Assessment-II when mothers showed initial serum ferritin >65 µg/L. In the other group, taking 20 mg/d of iron was positively associated with Working Memory Index, Intelligence Quotient, verbal fluency, and emotion recognition indices when women had initial serum ferritin >65 µg/L.

CONCLUSIONS

Prenatal iron supplementation adjusted to the maternal hemoglobin levels and baseline iron stores improves cognitive functioning in children aged 4 years.

Iron Deposition Characteristics of Deep Gray Matter in Elderly Individuals in the Community Revealed by Quantitative Susceptibility Mapping and Multiple Factor Analysis

Purpose

The objective of this study was to determine which factors influence brain iron concentrations in deep gray matter in elderly individuals and how these factors influence regional brain iron concentrations.

Methods

A total of 105 elderly individuals were enrolled in this study. All participants underwent detailed magnetic resonance imaging (MRI) examinations from October 2018 to August 2019. Among them, 44 individuals had undergone a previous MRI examination from July 2010 to August 2011. Quantitative susceptibility mapping (QSM) was utilized as an indirect quantitative marker of brain iron, and the susceptibility values of deep gray matter structures were obtained. Univariate analysis and multiple linear regression analysis were used to investigate 11 possible determinants for cerebral iron deposition.

Results

Our results showed no sex- or hemisphere-related differences in susceptibility values in any of the regions studied. Aging was significantly correlated with increased insusceptibility values in almost all analyzed brain regions (except for the thalamus) when we compared the susceptibility values at the two time points. In a cross-sectional analysis, the relationship between gray matter nucleus susceptibility values and age was conducted using Pearson’s linear regression. Aging was significantly correlated with the susceptibility values of the globus pallidus (GP), putamen (Put), and caudate nucleus (CN), with the Put having the strongest correlations. In multiple linear regression models, associations with increased susceptibility values were found in the CN, Put, red nucleus, and dentate nucleus for individuals with a history of type 2 diabetes mellitus (T2DM). However, the patients with hypertension showed significantly reduced susceptibility values in the red nucleus and dentate nucleus. Our data suggested that smokers had increased susceptibility values in the thalamus. No significant associations were found for individuals with a history of hypercholesterolemia and Apolipoprotein E4 carrier status.

Conclusion

Our data revealed that aging, T2DM, and smoking could increase iron deposition in some deep gray matter structures. However, hypertension had the opposite effects in the red nuclei and dentate nuclei. Brain iron metabolism could be influenced by many factors in different modes. In future studies, we should strictly control for confounding factors.

The Role of Maternal Smoking in Sudden Fetal and Infant Death Pathogenesis

Maternal smoking is a risk factor for both sudden infant death syndrome (SIDS) and sudden intrauterine unexplained death syndrome (SIUDS). Both SIDS and SIUDS are more frequently observed in infants of smoking mothers. The global prevalence of smoking during pregnancy is 1.7% and up to 8.1% of women in Europe smoke during pregnancy and worldwide 250 million women smoke during pregnancy. Infants born to mothers who smoke have an abnormal response to hypoxia and hypercarbia and they also have reduced arousal responses. The harmful effects of tobacco smoke are mainly mediated by release of carbon monoxide and nicotine. Nicotine can enter the fetal circulation and affect multiple developing organs including the lungs, adrenal glands and the brain. Abnormalities in brainstem nuclei crucial to respiratory control, the cerebral cortex and the autonomic nervous system have been demonstrated. In addition, hypodevelopment of the intermediolateral nucleus in the spinal cord has been reported. It initiates episodic respiratory movements that facilitate lung development. Furthermore, abnormal maturation and transmitter levels in the carotid bodies have been described which would make infants more vulnerable to hypoxic challenges. Unfortunately, smoking cessation programs do not appear to have significantly reduced the number of pregnant women who smoke.

Ascorbic acid ameliorates lead-induced apoptosis in the cerebellar cortex of developing rats

We investigated the effects of the gestational administration of lead (Pb) and ascorbic acid on cerebellar development. Pregnant female rats were randomly assigned to the control, Pb, or Pb plus ascorbic acid (PA) groups; six offspring per cage were randomly selected for analysis. Compared to the control group, fewer Purkinje cells were observed in the Pb-exposed pups at postnatal day 21. However, co-administrating Pb and ascorbic acid inhibited the Pb-induced reduction in Purkinje cells. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining, which detected DNA fragmentation in the dying cells, showed more TUNEL-positive cells in the Pb group, while co-treatment with Pb and ascorbic acid mitigated the Pb-induced cellular degeneration. Using immunohistochemistry and immunoblotting, we additionally found that Pb exposure induced a rise in the apoptotic factor Bax in the cerebellum, while Pb plus ascorbic acid treatment ameliorated this Bax induction. Since, Pb competes with the iron in the cell and the accumulation of free iron triggers oxidative stress, we performed iron staining, which revealed that ascorbic acid prevented the Pb-induced rises in iron-reactive cells and iron-reactivity. The anti-oxidant enzyme manganese-dependent superoxide dismutase showed change patterns that were similar to those of iron in the cerebellum. Finally, the pups' blood Pb levels were highest in the Pb group but were reduced in the PA group. Our findings suggest that ascorbic acid effectively ameliorates Pb-induced apoptosis and oxidative stress in the cerebellum. The present results imply that ascorbic acid treatment during pregnancy may protect against Pb-mediated developmental impairments in the cerebellum.

Retroocular and Subdural Hemorrhage or Hemosiderin Deposits in Pediatric Autopsies

The presence of hemosiderin in the optic nerve sheath and/or retina is sometimes used to estimate the timing of injury in infants or children with suspected non-accidental head trauma. To determine the prevalence of hemosiderin in deaths not associated with trauma, we performed a prospective study of retroocular orbital tissue, cranial convexity, and cervical spinal cord dura mater in infants and children <2.5 years age. In 53 cases of non-traumatic death, approximately 70% had blood or hemosiderin within the orbital fat, ocular muscles, and parasagittal cranial and/or cervical spinal subdural compartment. This bleeding is likely a consequence of the birth process. None had evidence of hemorrhage within the optic nerve sheath. Premature birth was less likely associated with orbital tissue hemorrhage. Caesarean section birth (mainly nonelective) was not associated with lower prevalence. Residual hemosiderin was identifiable up to 36 weeks postnatal age, suggesting gradual disappearance after birth. Cardiopulmonary resuscitation (performed in the majority of cases) was not associated with acute hemorrhage. In 9 traumatic deaths, 6 had blood and/or hemosiderin within the optic nerve sheath. Knowledge of the potential presence and resolution of hemosiderin in these locations is important for medicolegal interpretation of childhood deaths associated with head or brain injury.

Updates on the Methodological Approaches for Carrying Out an In-Depth Study of the Cardiac Conduction System and the Autonomic Nervous System of Victims of Sudden Unexplained Fetal and Infant Death

This article contains a set of protocols for histopathological techniques that can be used for carrying out in-depth studies of cases of sudden infant death syndrome and sudden intrauterine unexplained fetal death syndrome. In order to enable researchers to advance hypotheses regarding the causes of the unexpected death of infants and fetuses, the authors propose three innovative and accurate methodologies for studying the cardiac conduction system, the peripheral cardiac nervous system, and the central autonomic nervous system. Over the years, these protocols have been developed, modified, and improved on a vast number of cases which has enabled pathologists to carry out the microscopic analyses of the structures which regulate life, in order to highlight all the possible morphological substrates of pathophysiological mechanisms that may underlie these syndromes.

In memory of our research professor Lino Rossi (1923–2004).

The importance of hemosiderin deposition in the infant brain: an autopsy study

BACKGROUND/AIM

Iron is an essential element involved in many metabolic processes. Presence and accumulation of iron in various body systems can result in different outcomes. Its accumulation in the central nervous system (CNS) cannot be detected routinely by application of hematoxylin-eosin staining. Detection of the presence of hemosiderin in the brain and cerebellum by application of Perls' dye is of importance in cases of infant deaths.

MATERIAL AND METHODS

In this study, brain and cerebellar specimens obtained from 52 eligible infants  (aged 0-1 years) autopsied in our institute between the years 2010 and 2013, independent of the cause of death, were analyzed in order to detect possible presence of hemosiderin. Perls' dye was used to detect histopathological staining intensity and distribution of hemosiderin in the brain and cerebellum.

RESULTS

Cases did not differ significantly as for the patients' age and gender (p =0.473), type of the culprit trauma (p =0.414), death/crime scene (p =0.587), and diagnosis groups (p =0.550). In this autopsy study blue colored hemosiderin granulations, stained with Perls' dye were detected in the brain (n: 39, 75%), and cerebellum (n: 35, 67.3%). A weakly negative, but significant correlation was detected between the postmortem interval and intensity values of cerebellar hemosiderin (Spearman's correlation coefficient: -0.381, p =0.024). A statistically significant difference was found between the distribution scores of cerebral hemosiderin in cases with and without trauma history (p =0.03). Median cerebral hemosiderin distribution scores were 2.5 and 2, respectively.

CONCLUSIONS

The detection of a correlation between the presence of cerebral and cerebellar hemosiderin, and postmortem interval in the age group of 0-1 years, should be interpreted as an important finding in the analysis of cerebral iron. The presence of hemosiderin in the CNS may be a significant finding in the elucidation of infant deaths and this procedure should be carried out on a routine basis.Hippokratia 2015; 19 (2):164-171.

The use of cluster and principal component analysis in the estimation of iron status in term newborns

OBJECTIVE

To assess the relationship between parameters of iron homeostasis in infants and clinical features characterizing newborns and their mothers.

METHODS

The goal of the present work was to determine nine iron status parameters, i.e. hepcidin, prohepcidin, soluble transferrin receptor, ferritin, total iron binding capacity, unsaturated iron binding capacity, transferrin saturation, erythropoietin and total iron concentration, in the cord blood of 57 term newborns as well as to determine the complete blood count in their mothers. Moreover, an appraisal of the relationships between all of the iron parameters, the mothers' hematological factors and 12 clinical attributes was carried out using both cluster analysis (CA) and principal component analysis (PCA).

RESULTS

We found that hepcidin is not correlated with its precursor, but it is strongly positively correlated with the total iron concentration. The CA divided all of the 24 parameters into three clusters and showed that certain clinical features, e.g. the APGAR score, mother's age or parity are related to the hepcidin and prohepcidin concentration.

CONCLUSION

We demonstrated that CA and PCA are efficacious methods for assessing the relationship between iron metabolism parameters in cord blood and large amounts of clinical characteristics.