The importance of iron deficiency in pregnancy on fetal, neonatal, and infant neurodevelopmental outcomes

Why cells need iron: a compendium of iron utilisation

Iron deficiency is globally prevalent, causing an array of developmental, haematological, immunological, neurological, and cardiometabolic impairments, and is associated with symptoms ranging from chronic fatigue to hair loss. Within cells, iron is utilised in a variety of ways by hundreds of different proteins. Here, we review links between molecular activities regulated by iron and the pathophysiological effects of iron deficiency. We identify specific enzyme groups, biochemical pathways, cellular functions, and cell lineages that are particularly iron dependent. We provide examples of how iron deprivation influences multiple key systems and tissues, including immunity, hormone synthesis, and cholesterol metabolism. We propose that greater mechanistic understanding of how cellular iron influences physiological processes may lead to new therapeutic opportunities across a range of diseases.

Early Growth and Impacts on Long-Term Neurodevelopment and Human Capital

BACKGROUND

Growth trajectories during the first 1,000 days from conception to 2 years influence human capital, predicting intelligence, skills and health in adults.

SUMMARY

This review describes current evidence on the impacts of adverse pregnancy outcomes such as low birth weight, preterm birth, small for gestational age, and infant nutrition on long-term neurodevelopment and summarizes interventions that have proven to be effective in improving child development and further impact human capital. To date, no globally standardized measurements of child development in low-medium-income countries exist, and comparisons among studies using different developmental scales are challenging. In the perinatal period, birth weight, gestational age at delivery and elevated placental blood flow resistance have been identified as the main risk factors for global neurological delay, poor neurosensory development and cerebral palsy. Although these adverse neurological outcomes have decreased in developed settings, it is still a problem in low-resource populations. Nutritional deficiencies are the main drivers of developmental impairment, notably iron, iodine and folate deficiencies, and environmental stressors during pregnancy such as air pollution, exposure to chemicals, substance abuse, smoking, and maternal/parental psychiatric disorders can affect the developing brain. Interventions aiming to improve maternal macro- and micronutrient status, delayed cord clamping, exclusive breastfeeding and nurturing care have demonstrated to be effective strategies to prevent perinatal complications known to affect child development.

[Summary PAPPS Childhood and Adolescence 2024]

In this document we present two important topics in childhood, one completely new, the promotion of reading in the first years of life, and the other is an update that continues to generate doubts and questions from Parents, caregivers and health professionals: Is it necessary to screen for iron deficiency in children under 5 years of age?

Assessment of fetal cardiac function in pregnant women with anemia: prospective case-control study

OBJECTIVE

To compare fetal cardiac function in pregnant women with iron deficiency anemia (IDA) vs healthy pregnant controls.

METHODS

This was a single-center, prospective, case-control study conducted in a tertiary hospital between November 2022 and September 2023. Women diagnosed with IDA who attended as outpatients at the pregnancy follow-up clinic at 30-34 weeks' gestation or who were hospitalized for intravenous iron treatment owing to profound anemia were included. The control group consisted of randomly selected gestational-age-matched pregnant women with no obstetric complications or comorbidities and who did not have anemia. Patients underwent two-dimensional imaging, followed by pulsed-wave Doppler and M-mode and tissue Doppler imaging (TDI) to evaluate fetal cardiac function. A fetal cardiac score was calculated using systolic, diastolic and global hemodynamic function parameters, and was compared between patients with IDA and those without. The fetal cardiac score was also assessed according to the severity of anemia in the IDA group.

RESULTS

A total of 150 patients, comprising 50 patients with IDA and 100 healthy pregnant women at 30-34 weeks' gestation, were included in the study. Of the patients with IDA, 20 had mild, 18 had moderate and 12 had severe anemia. The fetal myocardial performance index and isovolumetric relaxation time were significantly higher in the IDA group compared with the control group (P < 0.0001 for both), while isovolumetric contraction time was similar. Among the fetal tricuspid and mitral valve diastolic parameters, the E, A and E/A values were significantly lower in the IDA group (P < 0.05 for all). Mitral (MAPSE) and tricuspid (TAPSE) annular plane systolic excursions were significantly lower in the IDA group (P < 0.05 for both). The IDA group also had significantly lower values for the TDI parameters mitral and tricuspid E', A', S' and E'/A' ratio and a significantly higher E/E' ratio (P < 0.05 for all). Among the IDA subgroups, a significant decrease was observed in the tricuspid and mitral A, E and E/A ratio in fetuses whose mothers had severe anemia (P = 0.001). M-mode Doppler analysis revealed significantly lower fetal TAPSE and MAPSE in the patient group with severe maternal anemia (P = 0.001 for both). According to the subgroup comparison of TDI findings, the fetuses of mothers with severe anemia had significantly lower tricuspid and mitral E', A', S' and E'/A' ratio values and a significantly higher E/E' ratio (P < 0.05 for all). The fetal cardiac score was significantly higher in the maternal IDA group compared with the control group (P < 0.001). A significant negative correlation was found between maternal hemoglobin level and fetal cardiac score (P < 0.001).

CONCLUSIONS

We observed differences in fetal systolic and diastolic cardiac function in pregnancies with maternal IDA. Fetal cardiac function was affected more among patients with severe anemia. This study found an increased E/E' ratio in the fetuses of pregnant women with IDA, suggesting decreased fetal heart maturation. Prenatal fetal cardiac evaluation, especially in women with severe anemia, can facilitate a more seamless transition to the postnatal period for these newborns. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Vitamin D Deficiency and Maternal Diseases as Risk Factors for the Development of Macrosomia in Newborns

Background: The aim is to assess the association between the level of vitamin D, maternal diseases, and macrosomia in newborns. Methods: This study included 258 full-term newborns (86 newborns with macrosomia; and 172 newborns with normal weight). Enzyme immunoassays for the determination of vitamin D were performed. Results: Newborns with macrosomia were statistically significantly more likely to have severe vitamin D deficiency compared with control (13.5 ± 6.7 ng/mL vs. 21.3 ± 12.1 ng/mL; p < 0.05). In the main group, severe deficiency was found in 40.7% of newborns, in the control group this rate was 5.8% (χ2 = 71,788, df = 3, p < 0.001). Multiple regression analysis shows that statistically significant risk factors for the development of macrosomia were vitamin D deficiency in the cord blood (OR = 2.29), maternal age over 36 years old (OR = 19.54), and hypothyroidism (OR = 9.35). Conclusion: the results of our study demonstrate relationship between macrosomia in newborns and vitamin D deficiency in the cord blood, maternal overweight and obesity, maternal age and thyroid disease.

How I treat bleeding in hereditary hemorrhagic telangiectasia

ABSTRACT

Hereditary hemorrhagic telangiectasia (HHT; Osler-Weber-Rendu disease) affects 1 in 5000 persons, making it the second most common inherited bleeding disorder worldwide. Telangiectatic bleeding, primarily causing recurrent epistaxis and chronic gastrointestinal bleeding, is the most common and most important manifestation of this multisystem vascular disorder. HHT-associated bleeding results in substantial psychosocial morbidity and iron deficiency anemia that may be severe. Although there remain no regulatory agency-approved therapies for HHT, multiple large studies, including randomized controlled trials, have demonstrated the safety and efficacy of antifibrinolytics for mild-to-moderate bleeding manifestations and systemic antiangiogenic drugs including pomalidomide and bevacizumab for moderate-to-severe bleeding. This has led to a recent paradigm shift away from repetitive temporizing procedural management toward effective systemic medical therapeutics to treat bleeding in HHT. In this article, 4 patient cases are used to illustrate the most common and most challenging presentations of HHT-associated bleeding that hematologists are likely to encounter in daily practice. Built on a framework of published data and supported by extensive clinical experience, guidance is given for modern evidence-based approaches to antifibrinolytic therapy, antiangiogenic therapy, and iron deficiency anemia management across the HHT disease severity spectrum.

Neonatal Hypoxia-Ischemia alters Brain-Derived Contactin-2-Positive Extracellular Vesicles in the Mouse Plasma

Neonatal encephalopathy (NE) impairs white matter development and results in long-term neurodevelopmental deficits. Leveraging prior findings of altered neuronal proteins carried by brain-derived extracellular vesicles (EVs) that are marked by a neural-specific cell surface glycoprotein Contactin-2 (CNTN2) in NE infants, the present study aimed to determine the correlation between brain and circulating CNTN2+-EVs and whether NE alters circulating CNTN2+-EV levels in mice. Brain tissue and plasma were collected from postnatal day (P)7, 10, 11, 15 mice to determine the baseline CNTN2 correlation between these two compartments (n = 4-7/time point/sex). NE was induced in P10 pups. Brain and plasma samples were collected at 1, 3, 6, 24, and 120 h (n = 4-8/time point/sex). CNTN2 from brain tissue and plasma EVs were quantified using ELISA. ANOVA and linear regression analyses were used to evaluate changes and correlations between brain and plasma CNTN2+-EVs. In baseline experiments, CNTN2 in brain tissue and plasma EVs peaked at P10 with no sex-difference. Brain and plasma CNTN2+-EV showed a positive correlation across early postnatal ages. NE pups showed an elevated CNTN2 in brain tissue and EVs at 1 h and only in brain tissue at 24 h. NE also abolished the positive plasma-brain correlation. The findings establish a link for central CNTN2 and its release into circulation during early postnatal life. The immediate elevation and release of CNTN2 following NE highlight a potential molecular response shortly after a brain injurious event. Our findings further support the utility of circulating brain-derived EVs as a possible bioindicator of NE.

Impact of Maternal Environment and Inflammation on Fetal Neurodevelopment

During intrauterine life, external stimuli including maternal nutrition, lifestyle, socioeconomic conditions, anxiety, stress, and air pollution can significantly impact fetal development. The human brain structures begin to form in the early weeks of gestation and continue to grow and mature throughout pregnancy. This review aims to assess, based on the latest research, the impact of environmental factors on fetal and neonatal brain development, showing that oxidative stress and inflammation are implied as a common factor for most of the stressors. Environmental insults can induce a maternal inflammatory state and modify nutrient supply to the fetus, possibly through epigenetic mechanisms, leading to significant consequences for brain morphogenesis and neurological outcomes. These risk factors are often synergic and mutually reinforcing. Fetal growth restriction and preterm birth represent paradigms of intrauterine reduced nutrient supply and inflammation, respectively. These mechanisms can lead to an increase in free radicals and, consequently, oxidative stress, with well-known adverse effects on the offspring's neurodevelopment. Therefore, a healthy intrauterine environment is a critical factor in supporting normal fetal brain development. Hence, healthcare professionals and clinicians should implement effective interventions to prevent and reduce modifiable risk factors associated with an increased inflammatory state and decreased nutrient supply during pregnancy.

Our path from abnormal uterine bleeding and iron deficiency to impaired fetal development: A long and winding road

Abnormal uterine bleeding adversely impacts the lives of reproductive‐aged girls and women; furthermore, the resulting periconceptual iron deficiency risks enduring neurological sequelae in the child.