Maternal periconceptional folic acid intake and risk of autism spectrum disorders and developmental delay in the CHARGE (CHildhood Autism Risks from Genetics and Environment) case-control study

Reliability of a short diet and vitamin supplement questionnaire for retrospective collection of maternal nutrient intake

Background

Gestational nutrition can protect against adverse neurodevelopmental outcomes.

Objectives

We developed a short tool for collecting maternal nutritional intake during pregnancy to facilitate research in this area and compared its retrospective use to prospectively-collected food frequency questionnaires (FFQ).

Methods

Maternal nutritional intake was retrospectively assessed using three versions (full interview, full self-administered online, and shortened interview) of the Early Life Exposure Assessment Tool (ELEAT) among participants of the MARBLES pregnancy cohort study of younger siblings of autistic children. Retrospective responses were compared with responses to supplement questions and the validated 2005 Block FFQ prospectively collected in MARBLES during pregnancies 2-7 years prior. ELEAT nutrient values were calculated using reported food intake frequencies and nutrient values from the USDA nutrient database. Correlations between retrospectively- and prospectively-reported intake were evaluated using Kappa coefficients, Youden's J, and Spearman Rank Correlation Coefficients (rs).

Results

MARBLES FFQ dietary intakes were compared among 54 women who completed the ELEAT full form including 12 online, and among 23 who completed the ELEAT short form. Correlations across most foods were fair to moderate. Most ELEAT quantified nutrient values were moderately correlated (rs = 0.3-0.6) with those on the Block FFQ. Supplement questions in both MARBLES and the ELEAT were completed by 114 women. Kappas were moderate for whether or not supplements were taken, but modest for timing. Correlations varied by version and child diagnosis or concerns, and were higher when mothers completed the ELEAT when their child was 4 years old or younger.

Conclusions

With recall up to several years, ELEAT dietary and supplement module responses were modestly to moderately reliable and produced nutrient values moderately correlated with prospectively-collected measures. The ELEAT dietary and vitamin supplements modules can be used to rank participants in terms of intake of several nutrients relevant for neurodevelopment.

Decoding the genetic landscape of autism: A comprehensive review

BACKGROUND

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by heterogeneous symptoms and genetic underpinnings. Recent advancements in genetic and epigenetic research have provided insights into the intricate mechanisms contributing to ASD, influencing both diagnosis and therapeutic strategies.

AIM

To explore the genetic architecture of ASD, elucidate mechanistic insights into genetic mutations, and examine gene-environment interactions.

METHODS

A comprehensive systematic review was conducted, integrating findings from studies on genetic variations, epigenetic mechanisms (such as DNA methylation and histone modifications), and emerging technologies [including Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9 and single-cell RNA sequencing]. Relevant articles were identified through systematic searches of databases such as PubMed and Google Scholar.

RESULTS

Genetic studies have identified numerous risk genes and mutations associated with ASD, yet many cases remain unexplained by known factors, suggesting undiscovered genetic components. Mechanistic insights into how these genetic mutations impact neural development and brain connectivity are still evolving. Epigenetic modifications, particularly DNA methylation and non-coding RNAs, also play significant roles in ASD pathogenesis. Emerging technologies like CRISPR-Cas9 and advanced bioinformatics are advancing our understanding by enabling precise genetic editing and analysis of complex genomic data.

CONCLUSION

Continued research into the genetic and epigenetic underpinnings of ASD is crucial for developing personalized and effective treatments. Collaborative efforts integrating multidisciplinary expertise and international collaborations are essential to address the complexity of ASD and translate genetic discoveries into clinical practice. Addressing unresolved questions and ethical considerations surrounding genetic research will pave the way for improved diagnostic tools and targeted therapies, ultimately enhancing outcomes for individuals affected by ASD.

Disrupted prenatal metabolism may explain the etiology of suboptimal neurodevelopment: a focus on phthalates and micronutrients and their relationship to autism spectrum disorder

Pregnancy is a time of high metabolic coordination, as maternal metabolism adapts to support the growing fetus. Many of these changes are coordinated by the placenta, a critical fetal endocrine organ and the site of maternal-fetal crosstalk. Dysregulation in maternal and placental metabolism during pregnancy has been linked to adverse outcomes, including altered neurodevelopment. Autism spectrum disorder (ASD) is a neurodevelopmental disorder linked to metabolic alterations in both children and their mothers. Prenatal environmental exposures have been linked to risk of ASD through dysregulated maternal, placental, and fetal metabolism. In this review, we focus on recent studies investigating the associations between prenatal metabolism in the maternal-placental-fetal unit and the impact of prenatal environmental exposures to phthalates and micronutrients on ASD risk. By identifying the mechanisms through which phthalates and other ubiquitous endocrine disrupting chemicals influence development, and how nutritional interventions can impact those mechanisms, we can identify promising ways to prevent suboptimal neurodevelopment.

Placental-brain axis in females detected within broadly impacted metabolic gene networks protects against prenatal PCB exposure

Background

Neurodevelopmental disorders have a strong male bias that is poorly understood. Placenta is a rich source of molecular information about environmental interactions with genetics (including biological sex), that affect the developing brain. We investigated placental-brain transcriptional responses in an established mouse model of prenatal exposure to a human-relevant mixture of polychlorinated biphenyls (PCBs).

Results

To understand sex, tissue, and dosage effects in embryonic (E18) brain and placenta by RNAseq, we used weighted gene correlation network analysis (WGCNA) to create correlated gene networks that could be compared across sex or tissue. WGCNA revealed that expression within most correlated gene networks was significantly and strongly associated with PCB exposures, but frequently in opposite directions between male-female and placenta-brain comparisons. In both WGCNA and differentially expressed gene analyses, male brain showed more PCB-induced transcriptional changes than male placenta, but the reverse pattern was seen in females. Furthermore, non-monotonic dose responses to PCBs were observed in most gene networks but were most prominent in male brain. The transcriptomic effects of low dose PCB exposure were significantly reversed by dietary folic acid supplementation across both sexes, but these effects were strongest in female placenta. PCB-dysregulated and folic acid-reversed gene networks were commonly enriched in functions in metabolic pathways involved in energy usage and translation, with female-specific protective effects enriched in PPAR, thermogenesis, glycerolipids, and O-glycan biosynthesis, as opposed to toxicant responses in male brain.

Conclusions

The female protective effect in prenatal PCB exposures appears to be mediated by dose-dependent sex differences in transcriptional modulation of metabolism in placenta.

Newborn Dried Blood Spot Folate in Relation to Maternal Self-reported Folic Acid Intake, Autism Spectrum Disorder, and Developmental Delay

BACKGROUND

Maternal folic acid intake has been associated with decreased risk for neurodevelopmental disorders including autism spectrum disorder (ASD). Genetic differences in folate metabolism could explain some inconsistencies. To our knowledge, newborn folate concentrations remain unexamined.

METHODS

We measured folate in archived newborn dried blood spots of children from the CHARGE (Childhood Autism Risks from Genetics and the Environment) case-control study who were clinically confirmed at 24-60 months to have ASD (n = 380), developmental delay (n = 128), or typical development (n = 247). We quantified monthly folic acid intake from maternally-reported supplements and cereals consumed during pregnancy and 3 months prior. We assessed associations of newborn folate with maternal folic acid intake and with ASD or developmental delay using regression. We stratified estimates across maternal and child MTHFR genotypes.

RESULTS

Among typically developing children, maternal folic acid intake in prepregnancy and each pregnancy month and prepregnancy prenatal vitamin intake were positively associated with newborn folate. Among children with ASD, prenatal vitamin intake in pregnancy months 2-9 was positively associated with newborn folate. Among children with developmental delay, maternal folic acid and prenatal vitamins during the first pregnancy month were positively associated with neonatal folate. Associations differed by MTHFR genotype. Overall, neonatal folate was not associated with ASD or developmental delay, though we observed associations with ASD in children with the MTHFR 677 TT genotype (odds ratio: 1.76, 95% CI = 1.19, 2.62; P for interaction = 0.08).

CONCLUSION

Maternal prenatal folic acid intake was associated with neonatal folate at different times across neurodevelopmental groups. Neonatal folate was not associated with reduced ASD risk. MTHFR genotypes modulated these relationships.

Food, nutrition, and autism: from soil to fork

Food and nutrition-related factors have the potential to impact development of autism spectrum disorder (ASD) and quality of life for people with ASD, but gaps in evidence exist. On 10 November 2022, Tufts University's Friedman School of Nutrition Science and Policy and Food and Nutrition Innovation Institute hosted a 1-d meeting to explore the evidence and evidence gaps regarding the relationships of food and nutrition with ASD. This meeting report summarizes the presentations and deliberations from the meeting. Topics addressed included prenatal and child dietary intake, the microbiome, obesity, food-related environmental exposures, mechanisms and biological processes linking these factors and ASD, food-related social factors, and data sources for future research. Presentations highlighted evidence for protective associations with prenatal folic acid supplementation and ASD development, increases in risk of ASD with maternal gestational obesity, and the potential for exposure to environmental contaminants in foods and food packaging to influence ASD development. The importance of the maternal and child microbiome in ASD development or ASD-related behaviors in the child was reviewed, as was the role of discrimination in leading to disparities in environmental exposures and psychosocial factors that may influence ASD. The role of child diet and high prevalence of food selectivity in children with ASD and its association with adverse outcomes were also discussed. Priority evidence gaps identified by participants include further clarifying ASD development, including biomarkers and key mechanisms; interactions among psychosocial, social, and biological determinants; interventions addressing diet, supplementation, and the microbiome to prevent and improve quality of life for people with ASD; and mechanisms of action of diet-related factors associated with ASD. Participants developed research proposals to address the priority evidence gaps. The workshop findings serve as a foundation for future prioritization of scientific research to address evidence gaps related to food, nutrition, and ASD.

Developmental pyrethroid exposure in mouse leads to disrupted brain metabolism in adulthood

Environmental and genetic risk factors, and their interactions, contribute significantly to the etiology of neurodevelopmental disorders (NDDs). Recent epidemiology studies have implicated pyrethroid pesticides as an environmental risk factor for autism and developmental delay. Our previous research showed that low-dose developmental exposure to the pyrethroid pesticide deltamethrin in mice caused male-biased changes in the brain and in NDD-relevant behaviors in adulthood. Here, we used a metabolomics approach to determine the broadest possible set of metabolic changes in the adult male mouse brain caused by low-dose pyrethroid exposure during development. Using a litter-based design, we exposed mouse dams during pregnancy and lactation to deltamethrin (3 mg/kg or vehicle every 3 days) at a concentration well below the EPA-determined benchmark dose used for regulatory guidance. We raised male offspring to adulthood and collected whole brain samples for untargeted high-resolution metabolomics analysis. Developmentally exposed mice had disruptions in 116 metabolites which clustered into pathways for folate biosynthesis, retinol metabolism, and tryptophan metabolism. As a cross-validation, we integrated metabolomics and transcriptomics data from the same samples, which confirmed previous findings of altered dopamine signaling. These results suggest that pyrethroid exposure during development leads to disruptions in metabolism in the adult brain, which may inform both prevention and therapeutic strategies.

Developmental pyrethroid exposure in mouse leads to disrupted brain metabolism in adulthood

Environmental and genetic risk factors, and their interactions, contribute significantly to the etiology of neurodevelopmental disorders (NDDs). Recent epidemiology studies have implicated pyrethroid pesticides as an environmental risk factor for autism and developmental delay. Our previous research showed that low-dose developmental exposure to the pyrethroid pesticide deltamethrin in mice caused male-biased changes in the brain and in NDD-relevant behaviors in adulthood. Here, we used a metabolomics approach to determine the broadest possible set of metabolic changes in the adult male mouse brain caused by low-dose pyrethroid exposure during development. Using a litter-based design, we exposed mouse dams during pregnancy and lactation to deltamethrin (3 mg/kg or vehicle every 3 days) at a concentration well below the EPA-determined benchmark dose used for regulatory guidance. We raised male offspring to adulthood and collected whole brain samples for untargeted high-resolution metabolomics analysis. Developmentally exposed mice had disruptions in 116 metabolites which clustered into pathways for folate biosynthesis, retinol metabolism, and tryptophan metabolism. As a cross-validation, we integrated metabolomics and transcriptomics data from the same samples, which confirmed previous findings of altered dopamine signaling. These results suggest that pyrethroid exposure during development leads to disruptions in metabolism in the adult brain, which may inform both prevention and therapeutic strategies.

Association of the retinol to all-trans retinoic acid pathway with autism spectrum disorder

BACKGROUND

Autism spectrum disorder (ASD) is a complex group of neurodevelopmental disorders. Research has highlighted a close association between the retinoic acid (RA) signaling pathway and ASD. This study investigates alterations in the vitamin A (VA, retinol) to RA metabolic pathway in children with ASD and speculates on the underlying reasons for these changes. We propose a subtype characterized by downregulated RA signaling in ASD, laying the groundwork for precise diagnosis and treatment research.

METHODS

We included 489 children with ASD and 280 typically developing (TD) children. Those with ASD underwent evaluations of core symptoms and neuro-developmental levels, which were conducted by professional developmental behavior physicians using assessment scales. Serum VA and all-trans RA (atRA) levels were determined by high-performance liquid chromatography and ultra-high-performance liquid chromatography-tandem mass spectrometry. The expression levels and concentrations of enzyme molecules such as retinol dehydrogenase 10 were assessed using quantitative polymerase chain reaction and enzyme-linked immunosorbent assay.

RESULTS

Children with ASD exhibited reduced serum atRA, accompanied by a downregulation of atRA synthesis enzymes. The reduction in serum atRA levels was linked not only to VA levels but also to the aberrant expression of metabolic enzymes responsible for atRA. Furthermore, the serum atRA levels in children with ASD were more strongly correlated with core symptoms and neurodevelopmental levels than VA levels.

CONCLUSION

Children with ASD exhibited a dual regulation of reduced serum atRA levels, influenced by both VA levels and abnormal expression of atRA metabolic enzymes.

The Association Between Gastrointestinal Issues and Psychometric Scores in Children with Autism Spectrum Disorder, Developmental Delays, Down Syndrome, and Typical Development

Investigate the association between gastrointestinal (GI) issues and psychometric scores among children with developmental delays and typical development. We examined the association between GI issues and the Mullen Scale of Early Learning (MSEL), Vineland Adaptive Behavior Subscales (VABS), and Aberrant Behavior Checklist (ABC) scores from participants with autism spectrum disorder (ASD), Down syndrome (DS), other developmental delays (DD) and typical development (TD) from the CHildhood Autism Risk from Genetics and Environment (CHARGE) Study (n = 1603). Approximately 32% of children with ASD, 31% of children with DD, and 20% of children with DS reported at least one GI issue, compared to 7% of TD controls. Constipation was the most frequently reported symptom for the entire population, including controls. In general, GI issues correlated with poorer behavioral scores (decreased communication, daily living, socialization, and motor skills on the VABS, and increased irritability/agitation, lethargy/social withdrawal, stereotypic behavior, and hyperactivity/noncompliance on the ABC) among ASD cases. Analysis by sex indicated that GI issues also correlated with poorer cognitive scores (fine motor, receptive language, expressive language, and MSEL composite scores), and adaptive behavior (communication skills, daily living skills, motor, and VABS composite scores) among boys with DD, but not girls with DD-suggesting sex differences among DD cases. Even TD controls showed increased stereotypic behavior and social withdrawal in association with GI issues. However, GI issues were not correlated with impairments in psychometric scores among DS cases. Given that GI issues correlate with deficits in behavioral and cognitive scores, future studies should investigate the treatment of GI symptoms in children with ASD and DD.

Pregnancy Planning and its Association with Autism Spectrum Disorder: Findings from the Study to Explore Early Development

OBJECTIVES

To examine associations between pregnancy planning and autism spectrum disorder (ASD) in offspring.

METHODS

The Study to Explore Early Development (SEED), a multi-site case-control study, enrolled preschool-aged children with ASD, other DDs, and from the general population (POP). Some children with DDs had ASD symptoms but did not meet the ASD case definition. We examined associations between mother's report of trying to get pregnant (pregnancy planning) and (1) ASD and (2) ASD symptomatology (ASD group, plus DD with ASD symptoms group combined) (each vs. POP group). We computed odds ratios adjusted for demographic, maternal, health, and perinatal health factors (aORs) via logistic regression. Due to differential associations by race-ethnicity, final analyses were stratified by race-ethnicity.

RESULTS

Pregnancy planning was reported by 66.4%, 64.8%, and 76.6% of non-Hispanic White (NHW) mothers in the ASD, ASD symptomatology, and POP groups, respectively. Among NHW mother-child pairs, pregnancy planning was inversely associated with ASD (aOR = 0.71 [95% confidence interval 0.56-0.91]) and ASD symptomatology (aOR = 0.67 [0.54-0.84]). Pregnancy planning was much less common among non-Hispanic Black mothers (28-32% depending on study group) and Hispanic mothers (49-56%) and was not associated with ASD or ASD symptomatology in these two race-ethnicity groups.

CONCLUSION

Pregnancy planning was inversely associated with ASD and ASD symptomatology in NHW mother-child pairs. The findings were not explained by several adverse maternal or perinatal health factors. The associations observed in NHW mother-child pairs did not extend to other race-ethnicity groups, for whom pregnancy planning was lower overall.

Immune Alterations in the Intrauterine Environment Shape Offspring Brain Development in a Sex-Specific Manner

Exposure to immune dysregulation in utero or in early life has been shown to increase risk for neuropsychiatric illness. The sources of inflammation can be varied, including acute exposures due to maternal infection or acute stress, or persistent exposures due to chronic stress, obesity, malnutrition, or autoimmune diseases. These exposures may cause subtle alteration in brain development, structure, and function that can become progressively magnified across the life span, potentially increasing the likelihood of developing a neuropsychiatric conditions. There is some evidence that males are more susceptible to early-life inflammatory challenges than females. In this review, we discuss the various sources of in utero or early-life immune alteration and the known effects on fetal development with a sex-specific lens. To do so, we leveraged neuroimaging, behavioral, cellular, and neurochemical findings. Gaining clarity about how the intrauterine environment affects offspring development is critically important for informing preventive and early intervention measures that may buffer against the effects of these early-life risk factors.

Maternal Thyroid Dysfunction During Pregnancy as an Etiologic Factor in Autism Spectrum Disorder: Challenges and Opportunities for Research

Background: Autism spectrum disorder (ASD) is a neurodevelopmental condition with unknown etiology. Both genetic and environmental factors have been associated with ASD. Environmental exposures during the prenatal period may play an important role in ASD development. This narrative review critically examines the evidence for a relationship between maternal thyroid dysfunction during pregnancy and ASD in the child. Summary: Studies that assessed the associations of hypothyroidism, hyperthyroidism, hypothyroxinemia, thyroid hormone concentrations, or autoimmune thyroid disease with ASD outcomes were included. Most research focused on the relationship between hypothyroidism and ASD. Multiple population-based studies found that maternal hypothyroidism was associated with higher likelihood of an ASD diagnosis in offspring. Associations with other forms of maternal thyroid dysfunction were less consistent. Findings may have been affected by misclassification bias, survival bias, or publication bias. Studies using medical records may have misclassified subclinical thyroid dysfunction as euthyroidism. Two studies that assessed children at early ages may have misclassified those with ASD as typically developing. Most studies adjusted for maternal body mass index (BMI) and/or mental illness, but not interpregnancy interval or pesticide exposure, all factors associated with fetal survival and ASD. Most studies reported a combination of null and statistically significant findings, although publication bias is still possible. Conclusions: Overall, evidence supported a positive association between maternal thyroid dysfunction during pregnancy and ASD outcomes in the child, especially for hypothyroidism. Future studies could reduce misclassification bias by using laboratory measures instead of medical records to ascertain thyroid dysfunction and evaluating children for ASD at an age when it can be reliably detected. Survival bias could be further mitigated by adjusting models for more factors associated with fetal survival and ASD. Additional research is needed to comprehensively understand the roles of maternal levothyroxine treatment, iodine deficiency, or exposure to thyroid-disrupting compounds in the relationship between maternal thyroid dysfunction and child ASD outcomes.

Examining associations of folic acid supplements administered to mothers during pre-conceptional and prenatal periods with autism spectrum disorders in their offspring: insights from a multi-center study in China

Objective

To investigate the relationship between maternal folic acid (FA) supplementation during the pre-conceptional and prenatal periods and the subsequent risk of autism spectrum disorder (ASD) in offspring.

Methods

A total of 6,049 toddlers aged 16-30 months were recruited from August 2016 to March 2017 for this cross-sectional study conducted in China. The parents of the enrolled toddlers provided information on maternal supplemental FA, socio-demographic information, and related covariates. Standard diagnostic procedures were implemented to identify toddlers with ASD.

Results

Among the 6,049 children included in the study, consisting of 3,364 boys with an average age of 22.7 ± 4.1 months, a total of 71 children (1.2%) were diagnosed with ASD. Mothers who did not consume FA supplements during the prenatal period were found to have a significantly increased risk of having offspring with ASD, in comparison to those who were exposed to FA supplements (odds ratio [OR] = 2.47). However, we did not find a similar association during the pre-conceptional period. Compared to mothers who consistently used FA supplements from pre-conception to the prenatal period, those who never used FA supplements were statistically significantly associated with a higher risk of ASD in their offspring (OR = 2.88).

Conclusion

This study indicated that providing continuous maternal FA supplementation during the pre-conceptional and prenatal periods may decrease the risk of ASD in offspring. The prenatal period is considered to be the most crucial time for intervention.

Supplementation with (6S)-5-methyltetrahydrofolic acid appears as effective as folic acid in maintaining maternal folate status while reducing unmetabolised folic acid in maternal plasma: a randomised trial of pregnant women in Canada

Folic acid supplementation is recommended during pregnancy to support healthy fetal development; (6S)-5-methyltetrahydrofolic acid ((6S)-5-MTHF) is available in some commercial prenatal vitamins as an alternative to folic acid, but its effect on blood folate status during pregnancy is unknown. To address this, we randomised sixty pregnant individuals at 8-21 weeks' gestation to 0·6 mg/d folic acid or (6S)-5-MTHF × 16 weeks. Fasting blood specimens were collected at baseline and after 16 weeks (endline). Erythrocyte and serum folate were quantified via microbiological assay (as globally recommended) and plasma unmetabolised folic acid (UMFA) via LC-MS/MS. Differences in biochemical folate markers between groups were explored using multivariable linear/quantile regression, adjusting for baseline concentrations, dietary folate intake and gestational weeks. At endline (n 54), the mean values and standard deviations (or median, inter-quartile range) of erythrocyte folate, serum folate and plasma UMFA (nmol/l) in those supplemented with (6S)-5-MTHF v. folic acid, respectively, were 1826 (sd 471) and 1998 (sd 421); 70 (sd 13) and 78 (sd 17); 0·5 (0·4, 0·8) and 1·3 (0·9, 2·1). In regression analyses, erythrocyte and serum folate did not differ by treatment group; however, concentrations of plasma UMFA in pregnancy were 0·6 nmol/l higher (95 % CI 0·2, 1·1) in those supplementing with folic acid as compared with (6S)-5-MTHF. In conclusion, supplementation with (6S)-5-MTHF may reduce plasma UMFA by ∼50 % as compared with supplementation with folic acid, the biological relevance of which is unclear. As folate is currently available for purchase in both forms, the impact of circulating maternal UMFA on perinatal outcomes needs to be determined.

Environmental Risk Factors in Autism Spectrum Disorder: A Narrative Review

Existing evidence indicates that environmental factors might contribute up to 50% of the variance in autism spectrum disorder (ASD) risk. This structured narrative review offers a comprehensive synthesis of current knowledge on environmental risk factors in ASD, including evaluation of conflicting evidence, exploration of underlying mechanisms, and suggestions for future research directions. Analysis of diverse epidemiological investigations indicates that certain environmental factors, including advanced parental age, preterm birth, delivery complications, and exposure to toxic metals, drugs, air pollutants, and endocrine-disrupting chemicals, are linked to an increased ASD risk through various mechanisms such as oxidative stress, inflammation, hypoxia, and its consequences, changes in neurotransmitters, disruption of signaling pathways and some others. On the other hand, pregnancy-related factors such as maternal diabetes, maternal obesity, and caesarian section show a weaker association with ASD risk. At the same time, other environmental factors, such as vaccination, maternal smoking, or alcohol consumption, are not linked to the risk of ASD. Regarding nutritional elements data are inconclusive. These findings highlight the significance of environmental factors in ASD etiology and emphasize that more focused research is needed to target the risk factors of ASD. Environmental interventions targeting modifiable risk factors might offer promising avenues for ASD prevention and treatment.

Prenatal folate deficiency impairs sociability and memory/recognition in mice offspring

Folate is essential for the normal growth and development of the fetus. Folic acid supplementation during the fetal period affects postnatal brain development and reduces the incidence of mental disorders in animal and human studies. However, the association between folate deficiency (FD) during pregnancy and developmental disorders in children remains poorly understood. In this study, we investigated whether prenatal FD is associated with neurodevelopmental disorders in offspring. ICR mice were fed a control diet (2 mg folic acid/kg diet) or a folate-deficient diet (0.3 mg folic acid/kg diet) from embryonic day 1 until parturition. We evaluated locomotor activity, anxiety, grooming, sociability and learning memory in male offspring at 7-10 weeks of age. No differences were found in locomotor activity or anxiety in the open field test, nor in grooming time in the self-grooming test. However, sociability, spatial memory, and novel object recognition were impaired in the FD mice compared with control offspring. Furthermore, we measured protein expression levels of the NMDA and AMPA receptors, as well as PSD-95 and the GABA-synthesizing enzymes GAD65/67 in the frontal cortex and hippocampus. In FD mice, expression levels of AMPA receptor 1 and PSD-95 in both regions were reduced compared with control mice. Moreover, NMDA receptor subunit 2B and GAD65/67 were significantly downregulated in the frontal cortex of prenatal FD mice compared with the controls. Collectively, these findings suggest that prenatal FD causes behavioral deficits together with a reduction in synaptic protein levels in the frontal cortex and hippocampus.

Associations of unintended pregnancy with autism spectrum disorders and the modification of folic acid supplements

There is limited evidence on the associations of unintended pregnancy with autism spectrum disorders (ASD). This study aimed to examine this relationship and the modification of pre-conceptional and prenatal folic acid supplements. Six thousand and five toddlers aged 16 to 30 months from seven cities of six provinces in China were eligible for participation. Information on unintended pregnancy and folic acid supplements was obtained via questionnaires from caregivers of toddlers. The diagnosis of ASD was based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and the Chinese version of the Childhood Autism Rating Scale (CARS). Of the 6005 toddlers in the study (3337 boys and 2668 girls), 71 (1.18%) received the diagnosis of ASD. Generalized linear models with a logit link function showed unintended pregnancy was positively associated with ASD (odds ratios [OR] = 1.69, 95% confidence interval [CI], 1.05-2.79). Stratified estimates indicated that the association remained stable among toddlers of mothers without pre-conceptional and prenatal folic acid supplements (OR = 2.75, 95% CI, 1.04-7.27; n = 1243, 20.70%). Unintended pregnancy was associated with higher odds of ASD in 16-30 months of toddlers, and the association was consistent among toddlers of mothers without prenatal folic acid supplements. Our findings emphasize the need to raise awareness of the risk of unintended pregnancy and the benefits of folic acid supplements among Chinese women.

Korean Clinical Guideline for Autism Spectrum Disorder - Clinical Features, Course, Epidemiology, and Cause

Autism spectrum disorder (ASD) is a heterogeneous developmental disorder characterized by impairments in two core areas: 1) social communication and interaction and 2) restricted and repetitive patterns of behaviors and interests. In general, ASD is known to be a lifelong disorder. Follow-up studies from childhood to adulthood have reported that the severity of the key symptoms ASD decreases over time. However, chronic health problems including mental health occur in many patients with ASD. The prevalence of ASD has increased from around 0.04% in the 1970s to 2.8% at present. The average age of diagnosis in developed countries is 38-120 months of age. Recent evidence suggests that biological factors which include genetic, congenital, immunological, neuroanatomical, biochemical, and environmental ones are important in causing autism. Until now, early signs and various risk factors of ASD have been suggested.

Prenatal folic acid and vitamin B12 imbalance alter neuronal morphology and synaptic density in the mouse neocortex

Previous reports have provided evidence that insufficient or excessive maternal folic acid (FA) intake during pregnancy can alter neurodevelopment of the offspring by modulating prenatal neurogenesis. Furthermore, our earlier work in a mouse model confirmed long-term structural changes at the cellular level of either deficient or excessive FA supply by comparably reducing dendritic arborization of cortical projection neurons. Here, we report that excessive amounts of FA decrease arborization of deep layer projection neurons, but not upper layer neurons and that reduced complexity of deep layer neurons is not observed when folic acid is replaced by folinic acid, a stable reduced form of folate. In addition, deficiency of B12, a vitamin that critically regulates folate metabolism, causes even more marked decreases in neuronal arborization in both deep and upper layer neurons and particularly in combination with FA excess. Furthermore, both FA excess and B12 deficiency affect synaptic density and morphology. Our findings point to neurodevelopmental risks associated with insufficient amounts of prenatal B12, particularly in association with high levels of FA intake, suggesting that the neurodevelopmental program is sensitive to an imbalance in the status of these interacting micronutrients.

Maternal- and child-related risk factors for autism during the perinatal period

Background

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder commonly prevalent in children worldwide including KSA. It causes disability in social interaction, communication, and restrictive and repetitive behaviors. Detecting risk factors for ASD could help initiate screening and risk prevention approaches. Herein, this study aimed to detect several maternal and neonatal risk factors for ASD in KSA.

Results

Ninety-four cases and 282 control completed an online survey tool. The survey items were close-ended questions. Participants were asked about maternal-related risk factors for autism during perinatal period. The logistic regression model revealed having a child diagnosed with autism with two predictors: factors related to the mother and factors related to the baby during perinatal period. The whole model was sig (p < 0.0001). The factors related to the baby have more impact on developing autism than maternal factors (OR is 3 vs 2.3, respectively, p < 0.01 for both).

Conclusion

The findings of this study will be beneficial for subsequent nationwide screenings and educational programs. The study brought to light the potential for identifying children in need of early intervention.

Genetic impairment of folate metabolism regulates cortical interneurons and social behavior

Introduction

The implications of folate deficiency in neuropsychiatric disorders were demonstrated in numerous studies. Genetic deficiency in a key folate metabolism enzyme, MTHFR, is an example of the interaction between genetic and environmental risk factors: the maternal MTHFR deficiency governs in-utero nutrient availability, and the embryo's Mthfr genotype influences its ability to metabolize folates. Here, we explore how the maternal and offspring Mthfr genotypes affect cortical interneuron densities and distributions, mouse social outcome, and the relation of the different interneuron patterns to cortical excitability.

Methods

Two experiments were conducted to examine the effects of maternal and offspring Mthfr-KO heterozygosity. Mice were tested for direct social interactions (DSIs), repetitive behavior and cortical laminar distribution of interneuron populations expressing glutamate-decarboxylase-65, parvalbumin and somatostatin. Susceptibility to seizure was tested by exposure to pentylenetetrazole (PTZ).

Results

Maternal Mthfr+/- genotype was associated with suppressed social activities and reduced interneuron densities in all layers of the retrosplenial cortex (RSC). Somatostatin density and the somatostatin/parvalbumin ratio in the RSC and frontal cortex positively correlated with social behavior in the mice. An interaction between maternal and offspring Mthfr genotypes resulted in higher susceptibility of wild-type offspring to PTZ induced seizure.

Discussion

Maternal folate metabolism was shown to be critical to interneuron ontogenesis. Our results demonstrate that interneurons have a specific susceptibility to folate deficiency that may mediate folate's involvement in neuropsychiatric disease. The relations between cortical somatostatin interneuron patterns and social behavior highlight this subpopulation of interneurons as a target for further research.

Maternal Serum Vitamin B12 during Pregnancy and Offspring Autism Spectrum Disorder

This study examined the association between maternal serum vitamin B12 levels during early pregnancy and offspring autism spectrum disorders (ASD) and subtypes. Based on a Finnish national birth cohort, case offspring (n = 1558) born in 1987-2007 and diagnosed with ASD by 2015 were matched with one control on date of birth, sex and place of birth. Maternal vitamin B12 levels were measured during first and early second trimesters of pregnancy. High maternal vitamin B12 levels (≥81th percentile) was associated with increased risk for offspring childhood autism, adjusted odds ratio, 1.59, 95% confidence interval 1.06-2.41 (p = 0.026). No significant associations were observed between maternal vitamin B12 levels and offspring Asperger's or pervasive developmental disorder/NOS.

Folate Supplementation in Women with Pre-Existing Diabetes

Folate supplementation in the periconceptual period is the standard of care for the prevention of neural tube defects. To support dietary folate intake, some countries have introduced mandatory folic acid fortification of food products. Robust evidence supports the additional use of a low-dose folic acid supplement (0.4 mg/day) in all women from 2-3 months preconception until the end of the 12th week of gestation. For women with pre-existing diabetes, high-dose folic acid supplementation (5 mg/day) is recommended in some, but not all international guidelines. The recommendation is made based on consensus opinion and reflects the increased risk of neural tube defects in pregnant women with pre-existing diabetes. However, there is limited evidence to clarify the high-risk groups that benefit from high-dose folic acid versus those that do not. There are also some data to suggest that high-dose folic acid may be harmful to mothers and offspring, although this issue remains controversial. This narrative review explores the evidence that supports the recommendation for women with pre-existing diabetes to take high-dose folic acid in the periconceptual period. It explores the potential benefits of high-dose supplemental folate beyond the prevention of neural tube defects, and also the potential adverse impacts of high-dose folate use. These topics are considered with a specific focus on the issues that are pertinent to women with pre-existing diabetes. Based on the available evidence, a pragmatic approach to the use of folic acid supplements in women with pre-existing diabetes during the periconception period is suggested. The need for comprehensive preconception care that optimises glycaemic control and addresses other modifiable risk factors before pregnancy is emphasized.

Placental DNA methylation profile as predicting marker for autism spectrum disorder (ASD)

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that impairs normal brain development and socio-cognitive abilities. The pathogenesis of this condition points out the involvement of genetic and environmental factors during in-utero life. Placenta, as an interface tissue between mother and fetus, provides developing fetus requirements and exposes it to maternal environment as well. Therefore, the alteration of DNA methylation as epigenetic consequence of gene-environmental interaction in the placenta could shed light on ASD pathogenesis. In this study, we reviewed the current findings on placental methylation status and its association with ASD. Differentially methylated regions (DMRs) in ASD-developing placenta were found to be mainly enriched in ASD gene loci affecting synaptogenesis, microtubule dynamics, neurogenesis and neuritogenesis. In addition, non-genic DMRs in ASD-placenta proposes an alternative contributing mechanism for ASD development. Our study highlights the importance of placental DNA methylation signature as a biomarker for ASD prediction.

Cohort-guided insights into gene-environment interactions in autism spectrum disorders

Prospective birth cohorts offer unprecedented opportunities to investigate the pathogenesis of complex disorders such as autism, in which gene-environment interactions must be appreciated in a temporal context. This Perspective article considers the history of autism research, including missteps that reflected an incomplete understanding of the epidemiology of autistic spectrum disorders, the effects of advocacy and philanthropy on the trajectory of scientific inquiry, and the current and future roles of prospective birth cohort research in illuminating the pathology of these and other complex disorders wherein exposures during gestation might not manifest until later in life.

Schmidt R, N. Pearce E. Prenatal Exposure to Per- and Polyfluoroalkyl Substances, Maternal Thyroid Dysfunction, and Child Autism Spectrum Disorder

Autism spectrum disorder (ASD), with its high economic and societal costs, is a growing public health concern whose prevalence has risen steadily over the last two decades. Although actual increased incidence versus improved diagnosis remains controversial, the increased prevalence of ASD suggests non-inherited factors as likely contributors. There is increasing epidemiologic evidence that abnormal maternal thyroid function during pregnancy is associated with increased risk of child ASD and other neurodevelopmental disorders. Prenatal exposure to endocrine-disrupting chemicals such as per- and polyfluoroalkyl substances (PFAS) is known to disrupt thyroid function and can affect early brain development; thus, thyroid dysfunction is hypothesized to mediate this relationship. The concept of a potential pathway from prenatal PFAS exposure through thyroid dysfunction to ASD etiology is not new; however, the extant literature on this topic is scant. The aim of this review is to evaluate and summarize reports with regard to potential mechanisms in this pathway.

Emotional and behavioral attitudes of Tunisian youth towards childhood leukemia: health education and primary prevention in perspective

Background

Given the increasing blood cancer incidence in Tunisia and recent discoveries proving the involvement of environmental factors, this study examined the environmental health literacy (EHL) of Tunisian secondary school students concerning not only this disease, but also their emotional and behavioral attitudes towards leukemia risks.

Methods

A cross-sectional survey was conducted among Tunisian youths (N = 372, 16–20 years; 68% females, 32% males). Data collection took place in four representative public secondary schools in the North, Center, and South of Tunisia. Students completed a paper and pencil questionnaire and described their EHL level of blood cancer, as well as their attitudes and interests in this disease. The statistical software (SPSS, v.25.0) was used to analyze the data collected.

Results

The results indicated low EHL levels of leukemia. Most youths failed to identify all the leukemogenic (except tobacco and pollution) and non- leukemogenic risk factors. Pesticide use and exposure to low frequency electromagnetic radiation were not considered risk factors. Proximity to heavy-traffic roads and benzene exposure were not perceived by youth as risk factors. Despite these low levels, most participants were interested in having more information about leukemia and cancers in general.

Conclusion

This investigation shows a lack of knowledge about leukemia. Low EHL levels will incite educational actors and curriculum designers to optimize content and innovate ICT adapted to this environmental health challenge.

Maternal Folate Status and the Relation between Gestational Arsenic Exposure and Child Health Outcomes

Gestational arsenic exposure adversely impacts child health. Folate-mediated 1-carbon metabolism facilitates urinary excretion of arsenic and may prevent arsenic-related adverse health outcomes. We investigated the potential for maternal folate status to modify associations between gestational arsenic exposure and child health. We used data from 364 mother-child pairs in the MIREC study, a prospective pan-Canadian cohort. During pregnancy, we measured first trimester urinary arsenic concentrations, plasma folate biomarkers, and folic acid supplementation intake. At age 3 years, we evaluated twelve neurodevelopmental and anthropometric features. Using latent profile analysis and multinomial regression, we developed phenotypic profiles of child health, estimated covariate-adjusted associations between arsenic and these phenotypic profiles, and evaluated whether folate status modified these associations. We identified three phenotypic profiles of neurodevelopment and three of anthropometry, ranging from less to more optimal child health. Gestational arsenic was associated with decreased odds of optimal neurodevelopment. Maternal folate status did not modify associations of arsenic with neurodevelopmental phenotypic profiles, but gestational arsenic was associated with increased odds of excess adiposity among those who exceed recommendations for folic acid (>1000 μg/day). However, arsenic exposure was low and folate status was high. Gestational arsenic exposure may adversely impact child neurodevelopment and anthropometry, and maternal folate status may not modify these associations; however, future work should examine these associations in more arsenic-exposed or lower folate-status populations.

Developmental exposure to vitamin D deficiency and subsequent risk of schizophrenia

Over the last half century, a body of convergent evidence has accumulated linking disruption of early brain development with an increased risk of mental disorders, including schizophrenia. The orderly cascade of brain development may be disrupted by exposure to suboptimal concentrations of a range of biological substrates and micronutrients. We hypothesized that those exposed to vitamin D deficiency during early life, have an increased risk of neurodevelopmental disorders, including schizophrenia. The hypothesis was based on the link between an increased risk of schizophrenia in (a) those born in winter and spring, when vitamin D deficiency is more prevalent, and (b) the offspring of dark-skinned migrants living in cold climates, who have a markedly increased risk of vitamin D deficiency. In this review, we summarize evidence from analytic epidemiology related to this hypothesis. Two case-control studies based on Danish neonatal dried blood spots have found that neonatal vitamin deficiency is associated with an increased risk of schizophrenia. However, recent genetic analyses have also suggested that common variants linked to schizophrenia may lead to lower vitamin D concentrations (possibly mediated via reduced outdoor activity). We summarize limitations of the current evidence and outline suggestions that can guide future research. Based on currently available data, there is insufficient evidence to support public health recommendations related to this topic. However, we cannot reject the hypothesis that the provision of vitamin D supplementation to pregnant women and/or offspring in groups vulnerable to vitamin D deficiency may subsequently reduce the incidence of schizophrenia in the offspring.

Choline, folic acid, Vitamin D, and fetal brain development in the psychosis spectrum

Choline, folic acid, and Vitamin D are essential for fetal brain development that may be the first steps in the pathogenesis of the psychotic spectrum. Micronutrient deficiencies have been associated with changes in fetal brain development, manifest as early problems in childhood behavior, and cognition, and later as increased incidence of psychotic and autism spectrum disorders. Micronutrient supplements may not only prevent deficiency, but they may also positively affect brain development in the context of other maternal risk factors, including maternal infection, stress, inflammation, and substance abuse. Many genes associated with later psychotic illness are highly expressed in the fetal brain, where they are responsible for various neurodevelopmental mechanisms. Interaction of micronutrient vitamins with these genetically programmed mechanisms to prevent pathological brain development associated with later psychosis is under active investigation. In addition to their effects on brain development, micronutrient vitamins have effects on other aspects of gestation and fetal development, including the prevention of premature delivery and other developmental abnormalities. Supplemental micronutrient vitamins should be part of good prenatal care, as has already happened for folic acid and Vitamin D and is now advocated by the American Medical Association for choline. The benefits of these micronutrient supplements include protection of brain development and the possibility of decreased risk for future psychotic disorders in those children who are either genetically or environmentally vulnerable. The purpose of this review is to present the current evidence supporting the safety and effectiveness of micronutrients in gestation and to suggest areas for future research.

Cerebral Folate Deficiency Syndrome: Early Diagnosis, Intervention and Treatment Strategies

Cerebral folate deficiency syndrome (CFDS) is defined as any neuropsychiatric or developmental disorder characterized by decreased CSF folate levels in the presence of normal folate status outside the nervous system. The specific clinical profile appears to be largely determined by the presence or absence of intrauterine folate deficiency as well as postnatal age at which cerebral folate deficiency occurs. The primary cause of CFDS is identified as the presence of serum folate receptor-alpha (FRα) autoantibodies impairing folate transport across the choroid plexus to the brain whereas, in a minority of cases, mitochondrial disorders, inborn errors of metabolism and loss of function mutations of the FRα (FOLR1) gene are identified. Early recognition and diagnosis of CFDS and prompt intervention is important to improve prognosis with successful outcomes. In this article we focus on FRα autoimmunity and its different age-dependent clinical syndromes, the diagnostic criteria, and treatments to be considered, including prevention strategies in this at-risk population.

Robust determinants of neurocognitive development in children: evidence from the Pune Maternal Nutrition Study

Neurocognitive development is a dynamic process over the life course and is influenced by intrauterine factors as well as later life environment. Using data from the Pune Maternal Nutrition Study from 1994 to 2008, we investigate the association of in utero, birth, and childhood conditions with offspring neurocognitive development in 686 participants of the cohort, at age 12 years. The life course exposure variables in the analysis include maternal pre-pregnancy size and nutrition during pregnancy, offspring birth measurements, nutrition and physical growth at age 12 years along with parental education and socio-economic status. We used the novel Bayesian Model Averaging (BMA) approach; which has been shown to have better predictive performance over traditional tests of associations. Our study employs eight standard neurocognitive tests that measure intelligence, working memory, visuo-conceptual and verbal learning, and decision-making/attention at 12 years of age. We control for nutritional-metabolic information based on blood measurements from the pregnant mothers and the children at 12 years of age. Our findings highlight the critical role of parental education and socio-economic background in determining child neurocognitive performance. Maternal characteristics (pre-pregnancy BMI, fasting insulin during pregnancy) and child height at 12 years were also robust predictors on the BMA. A range of early factors - such as maternal folate and ferritin concentrations during pregnancy, and child's head circumference at birth - remained important determinants of some dimensions of child's neurocognitive development, but their associations were not robust once we account for model uncertainty. Our results suggest that intrauterine influences on long- term neurocognitive outcomes may be potentially reversible by post-birth remediation. In addition to the current nutritional interventions, public health policy should also consider social interventions in children born into families with low socio-economic status to improve human capital.

The Role of Genetics, Epigenetics, and the Environment in ASD: A Mini Review

According to recent findings, variances in autism spectrum disorder (ASD) risk factors might be determined by several factors, including molecular genetic variants. Accumulated evidence has also revealed the important role of biological and chemical pathways in ASD aetiology. In this paper, we assess several reviews with regard to their quality of evidence and provide a brief outline of the presumed mechanisms of the genetic, epigenetic, and environmental risk factors of ASD. We also review some of the critical literature, which supports the basis of each factor in the underlying and specific risk patterns of ASD. Finally, we consider some of the implications of recent research regarding potential molecular targets for future investigations.

Prenatal exposure to pesticide residues in the diet in association with child autism-related traits: Results from the EARLI study

Prior work has suggested associations between prenatal exposure to several classes of pesticides and child autism spectrum disorder (ASD). We examined a previously developed pesticide residue burden score (PRBS) and intake of high pesticide residue foods in association with ASD-related traits. Participants were drawn from the Early Autism Risk Longitudinal Investigation (EARLI) (n = 256), a cohort following mothers who previously had a child with ASD through a subsequent pregnancy and that child's development. ASD-related traits were captured according to total Social Responsiveness Scale (SRS) scores at age 3 (mean raw total SRS score = 35.8). Dietary intake was assessed through a food frequency questionnaire collected during pregnancy. We also incorporated organic intake and fatty foods in modified versions of the PRBS. Associations between high-residue fruit and vegetable intake, the overall PRBS and modified versions of it, and SRS scores were assessed using multivariable linear regression. Overall, we did not observe associations between pesticide residues in foods and ASD-related outcomes, and modified versions of the PRBS yielded similar findings. However, reductions in ASD-related traits were observed with higher overall fruit and vegetable intake (adjusted estimates for Q4 vs. Q1: β -12.76, 95%CI -27.8, 2.3). Thus, findings from this high familial probability cohort did not suggest relationships between pesticide residues in the diet according to the PRBS and ASD-related traits. Beneficial effects of fruit and vegetable intake may influence these relationships. Future work should consider fruit and vegetable intake in association with ASD-related outcomes. LAY SUMMARY: Diet is the main source of exposure to most pesticides in use today. In this study, we examined the relationship between pesticide exposure from residues in the diet during pregnancy and child autism-related traits. We found that these pesticide residues from the diet were not related to child autism-related outcomes at age three. However, higher prenatal fruit and vegetable intake was associated with reductions in child autism-related traits.

Environmental exposures to pesticides, phthalates, phenols and trace elements are associated with neurodevelopment in the CHARGE study

OBJECTIVE

To determine if higher exposures measured in early childhood to environmental phenols, phthalates, pesticides, and/or trace elements, are associated with increased odds of having a diagnosis of Autism Spectrum Disorder (ASD), Developmental Delay (DD), or Other Early Concerns (OEC) compared to typically developing children (TD).

METHODS

This study included 627 children between the ages of 2-5 who participated in the Childhood Autism Risks from Genetics and Environment (CHARGE) study. Urine samples were collected at the same study visit where diagnostic assessments to confirm diagnosis indicated during the recruitment process were performed. Adjusted multinomial regression models of each chemical with diagnosis as the outcome were conducted. Additionally, two methods were used to analyze mixtures: repeated holdout multinomial weighted quantile sum (WQS) regression for each chemical class; and a total urinary mixture effect was assessed with repeated holdout random subset WQS.

RESULTS

Many urinary chemicals were associated with increased odds of ASD, DD or OEC compared to TD; however, most did not remain significant after false discovery rate adjustment. Repeated holdout WQS indices provided evidence for associations of both a phenol/paraben mixture effect and a trace element mixture effect on DD independently. In analyses adjusted for confounders and other exposures, results suggested an association of a pesticide mixture effect with increased risk for ASD. Results also suggested associations of a total urinary mixture with greater odds of both ASD and DD separately.

CONCLUSION

Higher concentrations of urinary biomarkers were associated with ASD, DD, and OEC compared to TD, with consistency of the results comparing single chemical analyses and mixture analyses. Given that the biospecimens used for chemical analysis were generally collected many months after diagnoses were made, the direction of any causal association is unknown. Hence findings may reflect higher exposures among children with non-typical development than TD children due to differences in behaviors, metabolism, or toxicokinetics.

Prenatal folic acid supplementation and autism spectrum disorder in 3-year-old offspring: the Japan environment and children's study

OBJECTIVE

We evaluated the relationship between prenatal folic acid supplementation and autism spectrum disorder (ASD) in 3-year-old offspring.

METHODS

We used data from the Japan Environment and Children's Study, a nationwide prospective birth cohort study. We analyzed the data to determine the association between folic acid supplement use and the incidence of ASD in offspring, and classified participants into three groups based on the time of initiation of folic acid supplementation, as follows: (1) preconception users of folic acid supplements and (2) post-conception users, and (3) non-users. The dietary folate intake of study participants was also classified into three groups (<200 µg, 200 µg to <400 µg, ≥400 µg).

RESULTS

Overall, 361 offspring of 96,931 participants with single pregnancies were diagnosed with ASD (0.37%). A total of 7,046 participants (7.3%) used folic acid supplements before conception, 29,984 (30.9%) took them after detection of pregnancy, and 59,901 (61.8%) never received them. Multivariate logistic regression analyses demonstrated no association between prenatal folic acid supplementation and ASD in offspring (preconception use: adjusted odds ratio [AOR], 1.189; 95% confidence interval [CI], 0.819-1.727 and post-conception use: AOR, 1.072; 95% CI, 0.840-1.368); additionally, no association was observed with the use of folic acid supplements and/or multivitamin supplements (preconception use: AOR, 1.273; 95% CI, 0.921-1.760 and post-conception use: AOR, 1.132; 95% CI, 0.885-1.449). Moreover, no significant association was observed in participants with combined prenatal supplement use and dietary folate intake.

CONCLUSIONS

Maternal use of folic acid supplements from the pre- or post-conception period was not significantly associated with ASD in 3-year-old offspring in Japan. Evaluation of the dietary folate intake from preconception also showed no significant association.

Brief Report: Pregnancy, Birth and Infant Feeding Practices: A Survey-Based Investigation into Risk Factors for Autism Spectrum Disorder

A succession of interconnected environmental factors is believed to contribute substantially to the development of autism spectrum disorder (ASD). This exploratory study therefore aims to identify potential risk factors for ASD that are associated with pregnancy, birth and infant feeding. Demographic and health-related data on children aged 3-13 years (N = 4306) was collected through an online survey completed by biological mothers. A fitted logistic regression model identified advanced maternal age, prenatal bleeding, pre-eclampsia, perinatal pethidine usage, foetal distress before birth and male sex of child as associated with an increased risk of ASD, whereas longer gestational duration demonstrated a protective effect. These findings highlight potential risk factors and predictor interrelationships which may contribute to overall ASD risk.

Maternal intake of folate during pregnancy and risk of cerebral palsy in the MOBAND-CP cohort

BACKGROUND

Folate prevents neural tube defects and may play a role in some neurodevelopmental disorders.

OBJECTIVES

We investigated whether higher intakes of periconceptional or midpregnancy folate, as recommended, were associated with a reduced risk of offspring cerebral palsy (CP).

METHODS

We included participants from the Nordic collaboration cohort consisting of mother-child dyads in the Danish National Birth Cohort and the Norwegian Mother, Father, and Child Cohort Study [combined as MOthers and BAbies in Norway and Denmark (MOBAND-CP)]. A total of 190,989 live-born children surviving the first year of life were included. Missing covariate data were multiply imputed. Our exposures were defined as any or no folic acid supplementation in gestational weeks (GWs) -4 to 8 (periconceptional), 9 to 12, and -4 to 12, and supplemental, dietary, and total folate during midpregnancy (GWs 22-25). CP overall and the unilateral and bilateral spastic subtypes, as well as CP with low or moderate/high gross motor function impairments, were our outcomes of interest.

RESULTS

Periconceptional folic acid supplementation was not associated with CP [adjusted odds ratio (aOR), 1.02; 95% CI: 0.82-1.28]. However, supplementation in GWs 9 to 12 was associated with a reduced risk of CP (aOR, 0.74; 95% CI: 0.57-0.96), and inverse associations were indicated for both the unilateral (aOR, 0.68; 95% CI: 0.46-1.02) and bilateral (aOR, 0.70; 95% CI: 0.49-1.02) spastic subtypes, although the associations were not statistically significant. Supplemental or dietary folate in midpregnancy alone were not associated with CP. Strong inverse associations were observed with low gross motor function impairment (aOR, 0.49; 95% CI: 0.29-0.83), while for unilateral CP the aOR was 0.63 (95% CI: 0.34-1.22) for intakes of ≥500 compared to ≤199 dietary folate equivalents/day during midpregnancy.

CONCLUSIONS

Our findings suggest that folate intakes in GWs 9 to 12 and midpregnancy were associated with lower risks of CP, while no association was observed for periconceptional supplementation.

Neurodevelopmental effects of maternal folic acid supplementation: a systematic review and meta-analysis

Folic acid, a water-soluble vitamin B nutrient, plays an important role not only in maintaining a healthy pregnancy but also in offspring brain development and function, however, it remains unclear whether maternal folic acid (FA) supplementation associated with the risk of different postnatal neurodevelopmental outcomes. Here, we performed a systematic review and meta-analysis on the impact of maternal FA supplementation on a wide range of postnatal neurodevelopmental outcomes which include intellectual development, risk of autistic traits, ADHD, behavior, language, and psychomotor problems, using studies extracted from the following databases, including MEDLINE, Web of Science, Cochrane Library, Scopus, EMBASE, and PsychInfo. Thirty-two cohort studies and seven case-control studies were included in this meta-analysis. In the present study, we found that prenatal FA supplementation had a positive impact on offspring's neurodevelopmental outcomes, including improved intellectual development and reduced risk of autism traits, ADHD, behavioral, and language problems. We also found that FA over-supplementation was not associated with an improvement in offspring's brain development, and may have a negative impact on offspring's neurodevelopmental outcomes. This study proved the first panoramic review on the relationship of FA supplementation with offspring's neurodevelopment. Further studies focusing on different dosages and periods of FA supplementation are needed.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.1993781 .

Knowledge of childhood autism among nurses working in governmental hospitals of Addis Ababa, Ethiopia

INTRODUCTION

Autism is a neurodevelopmental disorder that occurs in the early childhood period and is characterized by altered social interaction, communication problems, repetitive, and stereotyped behavior. Genetic, environmental, or physical risk factors are associated with prenatal, natal, or postnatal complications, leading to the development of autism spectrum disorders. Prompt diagnosis and management should be an integral component of the care provision in countries like Ethiopia.

OBJECTIVE

This study aimed to assess knowledge of childhood autism among nurses working in governmental hospitals in Addis Ababa, Ethiopia.

METHODS

Institutional based cross-sectional study design was used. The sample size was calculated using the single population proportion formula, and the final sample size was 360. Final study subjects were selected by using the simple random sampling method. Data were collected using structured self-administered questionnaires and were then coded and entered into Epi-data version 3.1 and exported to SPSS version 21 for analysis. Descriptive statistics were utilized to show frequencies and percentages, and analysis of variance was carried out to compute the association between the dependent and independent variables. Independent t-test was also done to see the association between dependent variables and independent variables with two means. A p-value of less than 0.05 was considered statistically significant.

RESULTS

The mean score for knowledge-related items was 8.79 ± 0.4. In this study, out of 331 nurses, 180 (54.35%) had good knowledge. Significant mean score difference was observed among age distribution (F-Ratio = 2.8, p-value = 0.04), level of education (F-ratio = 13.97, p < 0.001) and work experience (F-Ratio = 3.07 p-value = 0.017).

CONCLUSION

A significant gap was observed in the overall knowledge of childhood autism among nurses employed in the governmental hospitals of Addis Ababa. The respondents' knowledge level was significantly different among age group distributions, education levels, and work experience.

Folinic Acid as Adjunctive Therapy in Treatment of Inappropriate Speech in Children with Autism: A Double-Blind and Placebo-Controlled Randomized Trial

This is a double-blind, placebo-controlled randomized trial to investigate the potential therapeutic effects of folinic acid/placebo as an adjuvant to risperidone on inappropriate speech and other behavioral symptoms of autism spectrum disorder (ASD). Fifty-five ASD children (age (mean ± standard deviation) = 13.40 ± 2.00; male/female: 35/20) were evaluated for behavioral symptoms at baseline, week 5, and week 10 using the aberrant behavior checklist-community (ABC-C). Folinic acid dosage was 2 mg/kg up to 50 mg per day for the entire course of the study. The repeated measures analysis showed significant effect for time × treatment interaction on inappropriate speech (F = 3.51; df = 1.61; P = 0.044), stereotypic behavior (F = 4.02; df = 1.37; P = 0.036), and hyperactivity/noncompliance (F = 6.79; df = 1.66; P = 0.003) subscale scores. In contrast, no significant effect for time × treatment interaction was found on lethargy/social withdrawal (F = 1.06; df = 1.57; P = 0.336) and irritability (F = 2.86; df = 1.91; P = 0.064) subscale scores. Our study provided preliminary evidence suggesting that folinic acid could be recommended as a beneficial complementary supplement for alleviating speech and behavioral symptoms in children with ASD.Clinical trial registeration: This trial was registered in the Iranian Registry of Clinical Trials ( www.irct.ir ; No. IRCT20090117001556N114).

Folic Acid and Autism: A Systematic Review of the Current State of Knowledge

Folic acid has been identified to be integral in rapid tissue growth and cell division during fetal development. Different studies indicate folic acid’s importance in improving childhood behavioral outcomes and underline its role as a modifiable risk factor for autism spectrum disorders. The aim of this systematic review is to both elucidate the potential role of folic acid in autism spectrum disorders and to investigate the mechanisms involved. Studies have pointed out a potential beneficial effect of prenatal folic acid maternal supplementation (600 µg) on the risk of autism spectrum disorder onset, but opposite results have been reported as well. Folic acid and/or folinic acid supplementation in autism spectrum disorder diagnosed children has led to improvements, both in some neurologic and behavioral symptoms and in the concentration of one-carbon metabolites. Several authors report an increased frequency of serum auto-antibodies against folate receptor alpha (FRAA) in autism spectrum disorder children. Furthermore, methylene tetrahydrofolate reductase (MTHFR) polymorphisms showed a significant influence on ASD risk. More clinical trials, with a clear study design, with larger sample sizes and longer observation periods are necessary to be carried out to better evaluate the potential protective role of folic acid in autism spectrum disorder risk.

One carbon metabolism and early development: a diet-dependent destiny

One carbon metabolism (OCM) is critical for early development, as it provides one carbon (1C) units for the biosynthesis of DNA, proteins, and lipids and epigenetic modification of the genome. Epigenetic marks established early in life can be maintained and exert lasting impacts on gene expression and functions later in life. Animal and human studies have increasingly demonstrated that prenatal 1C nutrient deficiencies impair fetal growth, neurodevelopment, and cardiometabolic parameters in childhood, while sufficient maternal 1C nutrient intake is protective against these detrimental outcomes. However, recent studies also highlight the potential risk of maternal 1C nutrient excess or imbalance in disrupting early development. Further studies are needed to delineate the dose-response relationship among prenatal 1C nutrient exposure, epigenetic modifications, and developmental outcomes.

Prenatal Vitamins and the Risk of Offspring Autism Spectrum Disorder: Systematic Review and Meta-Analysis

Prenatal nutrition is associated with offspring autism spectrum disorder (herein referred to as autism), yet, it remains unknown if the association is causal. Triangulation may improve causal inference by integrating the results of conventional multivariate regression with several alternative approaches that have unrelated sources of bias. We systematically reviewed the literature on the relationship between prenatal multivitamin supplements and offspring autism, and evidence for the causal approaches applied. Six databases were searched up to 8 June 2020, by which time we had screened 1309 titles/abstracts, and retained 12 articles. Quality assessment was guided using Newcastle-Ottawa in individual studies, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) for the body of evidence. The effect estimates from multivariate regression were meta-analysed in a random effects model and causal approaches were narratively synthesised. The meta-analysis of prenatal multivitamin supplements involved 904,947 children (8159 cases), and in the overall analysis showed no robust association with offspring autism; however, a reduced risk was observed in the subgroup of high-quality observational studies (RR 0.77, 95% CI (0.62, 0.96), I2 = 62.4%), early pregnancy (RR 0.76, 95% CI (0.58; 0.99), I2 = 79.8%) and prospective studies (RR 0.69, 95% CI (0.48, 1.00), I2 = 95.9%). The quality of evidence was very low, and triangulation was of limited utility because alternative methods were used infrequently and often not robustly applied.

Fruit and vegetable consumption before and during pregnancy and developmental delays in offspring aged 2 years in Japan

The association between fruit and vegetable consumption before and during pregnancy and offspring’s physical growth has been well reported, but no study has focused on offspring’s neurological development. We aimed to explore the association between maternal fruit and vegetable consumption before and during pregnancy and developmental delays in their offspring aged 2 years. Between July 2013 and March 2017, 23 406 women were recruited for the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Fruit and vegetable consumption was calculated using FFQ, and offspring’s developmental delays were evaluated by the Ages & Stages Questionnaires, Third Edition (ASQ-3) for infants aged 2 years. Finally, 10 420 women and 10 543 infants were included in the analysis. Totally, 14·9 % of children had developmental delay when screened using the ASQ-3. Women in the highest quartile of vegetable consumption from pre-pregnancy to early pregnancy and from early to mid-pregnancy had lower odds of offspring’s developmental delays (OR 0·74; 95 % CI 0·63, 0·89 and OR 0·70; 95 % CI 0·59, 0·84, respectively) than women in the lowest quartile. Women in the highest quartile of fruit consumption from early to mid-pregnancy had lower odds of offspring’s developmental delays (OR 0·78; 95 % CI 0·66, 0·92) than women in the lowest quartile. In conclusion, high fruit and vegetable consumption before and during pregnancy was associated with a lower risk of developmental delays in offspring aged 2 years.

The Association of Prenatal Vitamins and Folic Acid Supplement Intake with Odds of Autism Spectrum Disorder in a High-Risk Sibling Cohort, the Early Autism Risk Longitudinal Investigation (EARLI)

We examined maternal prenatal vitamin use or supplemental folic acid intake during month one of pregnancy for association with autism spectrum disorder (ASD) in the Early Autism Risk Longitudinal Investigation, an enriched-risk pregnancy cohort. Total folic acid intake was calculated from monthly prenatal vitamins, multivitamins, and other supplement reports. Clinical assessments through age 3 years classified children as ASD (n = 38) or non-ASD (n = 153). In pregnancy month one, prenatal vitamin use (59.7%) was not significantly associated with odds of ASD (OR = 0.70, 95%CI 0.32, 1.53). Sample size was limited and residual confounding was possible. Given the estimated effect sizes in this and previous work, prenatal vitamin intake during early pregnancy could be a clinically useful preventative measure for ASD.

Genetics and Epigenetics of One-Carbon Metabolism Pathway in Autism Spectrum Disorder: A Sex-Specific Brain Epigenome?

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition affecting behavior and communication, presenting with extremely different clinical phenotypes and features. ASD etiology is composite and multifaceted with several causes and risk factors responsible for different individual disease pathophysiological processes and clinical phenotypes. From a genetic and epigenetic side, several candidate genes have been reported as potentially linked to ASD, which can be detected in about 10–25% of patients. Folate gene polymorphisms have been previously associated with other psychiatric and neurodegenerative diseases, mainly focused on gene variants in the DHFR gene (5q14.1; rs70991108, 19bp ins/del), MTHFR gene (1p36.22; rs1801133, C677T and rs1801131, A1298C), and CBS gene (21q22.3; rs876657421, 844ins68). Of note, their roles have been scarcely investigated from a sex/gender viewpoint, though ASD is characterized by a strong sex gap in onset-risk and progression. The aim of the present review is to point out the molecular mechanisms related to intracellular folate recycling affecting in turn remethylation and transsulfuration pathways having potential effects on ASD. Brain epigenome during fetal life necessarily reflects the sex-dependent different imprint of the genome-environment interactions which effects are difficult to decrypt. We here will focus on the DHFR, MTHFR and CBS gene-triad by dissecting their roles in a sex-oriented view, primarily to bring new perspectives in ASD epigenetics.

Folates, folic acid and preconception care - a review

The link between folate deficiency and congenital spina bifida defects was first suggested in the 1960s. Although the prevention of these defects by preconception folic acid supplementation was confirmed in a large multi-centre controlled trial in 1991, its subsequent implementation as health education advice has made very little difference. North America’s policy of folic acid fortification of flour and bread has had a beneficial impact. No European country has implemented fortification due to concern over possible adverse effects on older subjects, but a recent review shows these to be largely hypothetical and far outweighed by beneficial effects. Recent research by Menezo et al. has, however, shown that folic acid is ineffective for some women with severe fertility problems including recurrent miscarriage and failed in vitro fertilisation. There is a genetically determined bottleneck (677TT) in their folate metabolism that can be successfully overridden by going straight to the next step in the metabolic pathway and taking 5-methylytetrahydrofolate, as a preconception supplement. Menezo suggests that all women with fertility problems should be tested for 677TT. If fortification of flour and bread is to be implemented in the UK, there should be monitoring for possible adverse effects including the incidence of colorectal cancers and cognitive decline. In conclusion, whilst there are concerns that fortification could have a detrimental effect on these conditions, there is sound evidence that it would have much greater beneficial effects.