Birth weight and autism spectrum disorder: A population‐based nested case–control study

Mechanisms of neurodevelopmental toxicity of topiramate

Prescriptions for antiseizure medications (ASMs) have been rapidly growing over the last several decades due, in part, to an expanding list of clinical indications for which they are now prescribed. This trend has raised concern for potential adverse neurodevelopmental outcomes in ASM-exposed pregnancies. Recent large scale population studies have suggested that the use of topiramate (TOPAMAX, Janssen-Cilag), when prescribed for seizure control, migraines, and/or weight management, is associated with an increased risk for autism spectrum disorder (ASD), intellectual disability, and attention-deficit/hyperactivity disorder (ADHD) in exposed offspring. Here, we critically review epidemiologic evidence demonstrating the neurobehavioral teratogenicity of topiramate and speculate on the neuromolecular mechanisms by which prenatal exposure may perturb neurocognitive development. Specifically, we explore the potential role of topiramate's pharmacological interactions with ligand- and voltage-gated ion channels, especially GABAergic signaling, its effects on DNA methylation and histone acetylation, whether topiramate induces oxidative stress, and its association with fetal growth restriction as possible mechanisms contributing to neurodevelopmental toxicity. Resolving this biology will be necessary to reduce the risk of adverse pregnancy outcomes caused by topiramate or other ASMs.

Long-term health risk of offspring born from assisted reproductive technologies

Since the world's first in vitro fertilization baby was born in 1978, there have been more than 8 million children conceived through assisted reproductive technologies (ART) worldwide, and a significant proportion of them have reached puberty or young adulthood. Many studies have found that ART increases the risk of adverse perinatal outcomes, including preterm birth, low birth weight, small size for gestational age, perinatal mortality, and congenital anomalies. However, data regarding the long-term outcomes of ART offspring are limited. According to the developmental origins of health and disease theory, adverse environments during early life stages may induce adaptive changes and subsequently result in an increased risk of diseases in later life. Increasing evidence also suggests that ART offspring are predisposed to an increased risk of non-communicable diseases, such as malignancies, asthma, obesity, metabolic syndrome, diabetes, cardiovascular diseases, and neurodevelopmental and psychiatric disorders. In this review, we summarize the risks for long-term health in ART offspring, discuss the underlying mechanisms, including underlying parental infertility, epigenetic alterations, non-physiological hormone levels, and placental dysfunction, and propose potential strategies to optimize the management of ART and health care of parents and children to eliminate the associated risks. Further ongoing follow-up and research are warranted to determine the effects of ART on the long-term health of ART offspring in later life.

Hearing Loss and Disorders: The Repercussions of Climate Change

PURPOSE

Climate change is considered to be the greatest threat to human health in the 21st century, and its effects are accelerating. Extensive research has clearly demonstrated its increasing impact across the continuum of health conditions. Despite this, there has been limited attention to the ramifications of climate change on hearing loss and hearing disorders. This lack of consideration is somewhat surprising as the environment itself and its changing nature have a substantial effect on hearing.

METHOD

Tackling climate change could be the greatest global health opportunity of the 21st century. To address this issue, this tutorial provides a general introduction to climate change and its three major elements (pollution, infectious diseases, and extreme weather events) and their effects on health. The substantial consequences of climate change for the incidence, development, and exacerbation of hearing loss and disorders are clearly described and detailed.

CONCLUSIONS

The challenge of responding to this very real and escalating threat to hearing requires a combination of prevention, advocacy, and education. These three roles place audiologists in the perfect position to take action on the far-reaching effects of climate change on hearing loss and disorders. To respond to this challenge and to fulfill these roles, several strategies, ranging from the individual level to the global level, are delineated for audiologists to incorporate into their practice.

Microbiota-indole 3-propionic acid-brain axis mediates abnormal synaptic pruning of hippocampal microglia and susceptibility to ASD in IUGR offspring

BACKGROUND

Autism spectrum disorder (ASD) has been associated with intrauterine growth restriction (IUGR), but the underlying mechanisms are unclear.

RESULTS

We found that the IUGR rat model induced by prenatal caffeine exposure (PCE) showed ASD-like symptoms, accompanied by altered gut microbiota and reduced production of indole 3-propionic acid (IPA), a microbiota-specific metabolite and a ligand of aryl hydrocarbon receptor (AHR). IUGR children also had a reduced serum IPA level consistent with the animal model. We demonstrated that the dysregulated IPA/AHR/NF-κB signaling caused by disturbed gut microbiota mediated the hippocampal microglia hyperactivation and neuronal synapse over-pruning in the PCE-induced IUGR rats. Moreover, postnatal IPA supplementation restored the ASD-like symptoms and the underlying hippocampal lesions in the IUGR rats.

CONCLUSIONS

This study suggests that the microbiota-IPA-brain axis regulates ASD susceptibility in PCE-induced IUGR offspring, and supplementation of microbiota-derived IPA might be a promising interventional strategy for ASD with a fetal origin. Video Abstract.

Association between history of miscarriage and autism spectrum disorder

This case-control study was designed to examine the association between different types of miscarriage history and autism spectrum disorder (ASD), and determine whether the number of miscarriage history affects the risk of ASD. All of 2274 children with ASD and 1086 healthy controls were recruited. Sociodemographic and prenatal, perinatal, and neonatal characteristics were compared between the two groups. Multivariable logistic regression analyses were applied to investigate association between miscarriage history and ASD. Stratified analyses based on sex and types of miscarriages were similarly performed. History of miscarriage was potential risk factors for ASD ([aOR] = 2.919; 95% [CI] = 2.327-3.517). Stratified analyses revealed that induced ([aOR] = 2.763, 95% [CI] = 2.259-3.379) and spontaneous miscarriage history ([aOR] = 3.341, 95% [CI] = 1.939-4.820) were associated with high risk of ASD, respectively. A sex-biased ratio in the risk of ASD was observed between females ([aOR] = 3.049, 95% [CI] = 2.153-4.137) and males ([aOR] = 2.538, 95% [CI] = 1.978-3.251). Stratified analysis of induced miscarriage history revealed that only iatrogenic miscarriage history was associated with an increased risk ASD ([aOR] = 2.843, 95% [CI] = 1.534-4.268). Also, multiple spontaneous miscarriage histories ([aOR] = 1.836, 95% [CI] = 1.252-2.693) were associated with higher autism risk than one spontaneous miscarriages history ([aOR] = 3.016, 95% [CI] = 1.894-4.174). In conclusion, miscarriage history is related to an increased risk for ASD in offspring, which is affected by the types of miscarriage and sex of the fetus.

Early exposure to agricultural pesticides and the occurrence of autism spectrum disorder: a systematic review

Abstract Objective: The aim of this study was to evaluate the influence of early exposure to agricultural pesticides and their relationship with autism spectrum disorder. Data source: This systematic review was registered at PROSPERO as CRD42020204842. The subject was systematically analyzed on PubMed, Scopus, and Web of Science databases until April 2021. Only studies with humans with early exposure to agricultural pesticides and diagnosis of autism were included. Exclusion criteria were studies on pesticides for domestic or veterinary use and late exposure. There were no language and time restriction. The quality analysis of the studies used the Newcastle-Ottawa Scale. Data synthesis: Six case-control studies were included; three of them measured the route of exposure by maternal biomarkers and the others by the residence address. The studies had scores between moderate and high in the quality assessment tool. It was found high rates of association between early exposure to agricultural pesticides and autism and detection limit above the quantification for a sample of polychlorinated biphenyls, hexachlorobenzene, and dichlorodiphenyldichloroethylene. Conclusions: There is evidence concerning the exposure to agricultural pesticides in early life and the development of the autism spectrum disorder; however, more studies are required to better understand their possible association.

Exploring brainstem auditory evoked potentials and mental development index as early indicators of autism spectrum disorders in high-risk infants

This study of infants from Hubei Province, China examined brainstem auditory evoked potentials (BAEP) and mental development index (MDI) as possible early indicators associated with autism spectrum disorders (ASD). The 34 ASD cases and 102 controls who had recovered from perinatal conditions were matched for age, sex, gestational age, birth weight and maternal age. BAEP absolute latencies (AL) I, III, V and interpeak latencies (IPL) I-III, III-V, I-V were compared in ASD cases and controls at ages 1, 3 and 6 months. MDI scores were compared in these infants from 1 month to 2 years old. Multiple logistic regression analysis was performed to test associations among ASD, BAEP and MDI. Results showed BAEP AL I, V and IPL III-V prolonged in the ASD group (p < 0.001), and MDI scores in ASD cases sharply declining from 12 to 24 months (p < 0.001). Regression analysis revealed odds ratios (OR) indicating that ASD was likely associated with abnormal values of BAEP AL I at 1 and 3 months (OR_{AL I} : 4.27; OR_{AL I} : 4.13), and AL V at 6 months (OR_{AL V} : 7.85). Lower MDI scores (MDI < 80) in infants at 1, 3, and 6 months were likely associated with ASD (OR_MDI : 2.58; OR_MDI : 3.83; OR_MDI : 4.87). These data show that abnormal BAEP values and low MDI scores are independent factors associated with ASD, and that monitoring of BAEP and MDI during infancy might facilitate screening for ASD development.

Aperiodic electrophysiological activity in preterm infants is linked to subsequent autism risk

Approximately 7% of preterm infants receive an autism spectrum disorder (ASD) diagnosis. Yet, there is a significant gap in the literature in identifying prospective markers of neurodevelopmental risk in preterm infants. The present study examined two electroencephalography (EEG) parameters during infancy, absolute EEG power and aperiodic activity of the power spectral density (PSD) slope, in association with subsequent autism risk and cognitive ability in a diverse cohort of children born preterm in South Africa. Participants were 71 preterm infants born between 25 and 36 weeks gestation (34.60 ± 2.34 weeks). EEG was collected during sleep between 39 and 41 weeks postmenstrual age adjusted (40.00 ± 0.42 weeks). The Bayley Scales of Infant Development and Brief Infant Toddler Social Emotional Assessment (BITSEA) were administered at approximately 3 years of age adjusted (34 ± 2.7 months). Aperiodic activity, but not the rhythmic oscillatory activity, at multiple electrode sites was associated with subsequent increased autism risk on the BITSEA at three years of age. No associations were found between the PSD slope or absolute EEG power and cognitive development. Our findings highlight the need to examine potential markers of subsequent autism risk in high-risk populations other than infants at familial risk.

Pregnant Mothers' Medical Claims and Associated Risk of Their Children being Diagnosed with Autism Spectrum Disorder

A retrospective analysis of administrative claims containing a diverse mixture of ages, ethnicities, and geographical regions across the United States was conducted in order to identify medical events that occur during pregnancy and are associated with autism spectrum disorder (ASD). The dataset used in this study is comprised of 123,824 pregnancies of which 1265 resulted in the child being diagnosed with ASD during the first five years of life. Logistic regression analysis revealed significant relationships between several maternal medical claims, made during her pregnancy and segmented by trimester, and the child's diagnosis of ASD. Having a biological sibling with ASD, maternal use of antidepressant medication and psychiatry services as well as non-pregnancy related claims such hospital visits, surgical procedures, and radiology exposure were related to an increased risk of ASD regardless of trimester. Urinary tract infections during the first trimester and preterm delivery during the second trimester were also related to an increased risk of ASD. Preventative and obstetrical care were associated with a decreased risk for ASD. A better understanding of the medical factors that increase the risk of having a child with ASD can lead to strategies to decrease risk or identify those children who require increased surveillance for the development of ASD to promote early diagnosis and intervention.

Autism spectrum disorder and air pollution: A systematic review and meta-analysis

Despite the widely-known effects of air pollution, pollutants exposure surrounding pregnancy and the risk for autism spectrum disorder (ASD) in newborns remains controversial. The purpose of our study was to carry out a systematic review and meta-analyses of the risk of ASD in newborns following air pollution exposure during the perinatal period (preconception to second year of life). The PubMed, Cochrane Library, Embase and ScienceDirect databases were searched for articles, published up to July 2020, with the keywords "air pollution" and "autism". Three models were used for each meta-analysis: a global model based on all risks listed in included articles, a pessimistic model based on less favorable data only, and an optimistic model based on the most favorable data only. 28 studies corresponding to a total of 758 997 newborns were included (47190 ASD and 703980 controls). Maternal exposure to all pollutants was associated with an increased risk of ASD in newborns by 3.9% using the global model and by 12.3% using the optimistic model, while the pessimistic model found no change. Each increase of 5 μg/m³ in particulate matter <2.5 μm (PM2.5) was associated with an increased risk of ASD in newborns, regardless of the model used (global +7%, pessimistic +5%, optimistic +15%). This risk increased during preconception (global +17%), during pregnancy (global +5%, and optimistic +16%), and during the postnatal period (global +11% and optimistic +16%). Evidence levels were poor for other pollutants (PM10, NOx, O3, metals, solvents, styrene, PAHs, pesticides). PM2.5 was associated with a greater risk than PM10 (coefficient 0.20, 95CI -0.02 to 0.42), NOx (0.29, 0.08 to 0.50) or solvents (0.24, 0.04 to 0.44). All models revealed that exposure to pollutants, notably PM2.5 during pregnancy, was associated with an increased risk of ASD in newborns. Pregnancy and postnatal periods seem to be the most at-risk periods.

Beyond Baby Siblings-Expanding the Definition of "High-Risk Infants" in Autism Research

PURPOSE OF REVIEW

Much of our understanding of early development in children with autism spectrum disorder (ASD) comes from studies of children with a family history of autism. We reviewed the current literature on neurodevelopmental profiles and autism prevalence from other high-risk infant groups to expose gaps and inform next steps. We focused on infants with early medical risk (e.g., preterm birth) and genetic risk (tuberous sclerosis complex [TSC]).

RECENT FINDINGS

About 7% of very preterm infants are later diagnosed with ASD. Prospective studies of early development outside of familial-risk infants are rare; however, recent work within preterm and TSC infants suggests interesting similarities and differences from infants with a family history of ASD. It is essential that we extend our knowledge of early markers of ASD beyond familial-risk infants to expand our knowledge of autism as it emerges in order to develop better, more individualized early interventions.

Understanding the association between gradient of cooking fuels and low birth weight in India

BACKGROUND

Birth weight is positively associated with physical and cognitive development of children and adversely associated with the use of unclean cooking fuels. Though studies have examined the contextual determinants of birth weight, no attempt has been made to understand the association of gradient of cooking fuels with birth weight in India. The objective of this paper is to understand the association of type of cooking fuel with low birth weight in India.

METHODS

Unit data from the fourth round of the National Family Health Survey (NFHS) (2015-16), covering 8206 singleton births from four states of India, was used in the analysis. These states reported more than 80% of birth weights by way of health cards issued by a public authority. Linear regression analysis was used to estimate mean birth weight, adjusting for confounders. We computed a new wealth index, excluding electricity and cooking fuels, using principal component analysis to capture the economic gradient of cooking fuel.

RESULTS

Our results suggest a strong gradient of cooking fuels on mean birth weight. The adjusted mean birth weight in households using electricity was 2957 g (95% CI: 2939-2975). It was 2908 g (95% CI: 2907-2910) for LPG, 2792 g (95% CI: 2784-2801) for biogas, 2819 g (95% CI: 2809-2829) for kerosene, 2841 g (95% CI: 2816-2866) for coal/lignite/charcoal, and 2834 g (95% CI: 2831-2836) in households using biomass. A difference of 165 g in predicted mean birth weight was found among children born in households that used electricity in relation to those that used biogas. The difference in relation to kerosene, coal/lignite/charcoal, and biomass was 138 g, 116 g, and 123 g respectively. Significant differences in mean birth weight were also observed by wealth quintiles, mother's underweight, social groups, birth interval, and mother's anemia status.

CONCLUSION

Findings from the study suggest to strengthen the policies on access to clean fuels and meet the interconnected goals of sustainable development.

Perinatal Factors in Newborn Are Insidious Risk Factors for Childhood Autism Spectrum Disorders: A Population-based Study

We analyzed claims data from the Taiwan National Health Insurance database, which contains data of 23.5 million Taiwan residents. We included children born after January 1, 2000 who had received a diagnosis of autism spectrum disorders (ASD). Patients who were not diagnosed with ASD were included in the control group. The ASD prevalence was 517 in 62,051 (0.83%) children. Neonatal jaundice, hypoglycemia, intrauterine growth retardation (IUGR), and craniofacial anomalies (CFA) differed significantly between the ASD and control groups. After logistic regressive analysis, the adjusted odds ratios of IUGR, CFA, neonatal hypoglycemia, and neonatal jaundice were 8.58, 7.37, 3.83, and 1.32, respectively. Those insidiously perinatal risk factors, namely CFA, IUGR, neonatal hypoglycemia, and neonatal jaundice, could increase the risk of ASD.

Association Study of MTHFR C677T Polymorphism and Birth Body Mass With Risk of Autism in Chinese Han Population

Objective: To explore the association of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism with birth body mass and risk of autism in Chinese Han population. Methods: A total 1,505 Chinese Han autism patients were recruited, using the Diagnostic and Statistical Manual of Mental Disorders, 4th revised version (DSM-IV-R) diagnostic criteria for autism, and 1,308 sex-matched healthy controls were also enrolled for the study. All the participants' birth body masses were counted according to the medical records. The MTHFR C677T genotypes were detected using the polymerase chain reaction-restrict fragment length polymorphism (PCR-RFLP) method. The association between C677T polymorphism, birth body mass, and risk of autism were analyzed using the chi-square tests. Results: The present study found that the MTHFR 677T was significantly associated with risk of autism [P = 0.004, odds ratio (OR) = 1.18, 95% CI = 1.02-1.29). The autism children more frequently showed low birth body mass (<2.5 kg) than healthy control subjects (8.6 vs. 5.3%, P = 0.001, OR = 1.67, 95% CI = 1.24-2.26). The interactive effects between MTHFR 677T and low birth body mass (P = 0.0001, OR = 2.18, 95% CI = 1.44-3.32) were also significantly associated with risk of autism. Conclusions: The MTHFR C677T polymorphism and low birth body mass may be associated with risk of autism in Chinese Han population.

Autism risk linked to prematurity is more accentuated in girls

INTRODUCTION

Prematurity has been identified as a risk factor for Autism Spectrum Disorder (ASD). The link between Autism Spectrum Disorder (ASD) and birth-week has not been strongly evidenced. We evaluated the correlation between the degree of prematurity and the incidence of autism in a cohort of 871 children born prematurely and followed from birth. The cohort was reduced to 416 premature infants born between 2011-2017 who were followed for 2-14 years, and analyzed according to birth week (degree of prematurity), and according to gender.

RESULTS

43 children (10.3%) received a definite diagnosis of ASD. There was a significant correlation between birth week and the risk of ASD, with 22.6% of children diagnosed with ASD when born at 25 weeks, versus 6% of ASD diagnoses at 31 weeks of prematurity. For children born after 32 weeks, the incidence decreased to 8-12.5%. A strong link was found between earlier birth week and increased autism risk; the risk remained elevated during near-term prematurity in boys. A correlation between early birth week and an elevated risk for ASD was seen in all children, but accentuated in females, gradually decreasing as birth week progresses; in males the risk for ASD remains elevated for any birth week.

CONCLUSION

A statistically significant increase in rates of autism was found with each additional week of prematurity. Females drove this direct risk related to degree of prematurity, while males had an elevated risk throughout prematurity weeks, even at near-term. We recommend including ASD screening in follow up of infants born prematurely, at all levels of prematurity.