Prenatal, perinatal, and neonatal factors in autism, pervasive developmental disorder-not otherwise specified, and the general population

Association of Preconception or Antepartum Maternal Intimate Partner Violence with Autism Spectrum Disorder in 3-Year-Old Offspring: The Japan Environment and Children's Study

Objective: We investigated the association between maternal antepartum intimate partner violence (IPV) and autism spectrum disorder (ASD) in 3-year-old offspring. Materials and Methods: Secondary analysis of the Japan Environment and Children's Study, a nationwide prospective birth-cohort study, for preconceptional and antepartum psychological/physical IPV against mothers was undertaken based on data obtained from a maternal self-report questionnaire. Subgroup analysis by four-level IPV frequency versus no IPV was conducted, and the incidence of ASD diagnosed during ages 2-3 years was estimated using self-reported questionnaire data of participants from when the child was 3 years old. Multivariate logistic regression was used to determine the association of preconceptional/antepartum IPV with ASD in 3-year-old offspring. Results: Among 79,324 offspring, 355 (0.45%) had ASD; preconceptionally and prenatally, 1,504 (1.9%) and 839 (1.1%) mothers were exposed to physical IPV whereas 9,162 (11.6%) and 10,240 (12.9%) mothers were exposed to psychological IPV, respectively. Multivariate logistic regression revealed a significant association of preconceptional physical IPV with ASD in offspring (adjusted odds ratio, 3.21; 95% confidence interval, 1.24-8.31), but not for antepartum physical IPV and preconceptional and antepartum psychological IPV. Conclusion: Preconceptional, but not antepartum, physical IPV was associated with ASD in 3-year-old offspring. Preconceptional and antepartum psychological IPV was unassociated with ASD in 3-year-old offspring. Preconceptional care through prevention of preconceptional physical IPV is important for neurodevelopment in offspring, and the mechanisms underlying the effects of IPV among nonpregnant individuals on ASD development in offspring should be elucidated.

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.

Investigating the borders of autism spectrum disorder: lessons from the former diagnosis of pervasive developmental disorder not otherwise specified

Introduction

Autism Spectrum Disorder (ASD) diagnosis is relatively consensual in typical forms. The margins of the spectrum and their degree of extension, however, are controversial. This has far-reaching implications, which extend beyond theoretical considerations: first, peripheral forms of autism are more prevalent than central forms; second, we do not know how relevant typical-targeted recommendations are for atypical forms. In DSM-IV-TR, these margins of autism were studied within the category of Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS). In spite of its low reliability, this former diagnosis was of particular interest to shed light on the gray area of margins. The aim of this systematic is therefore to investigate the clinical characteristics of PDD-NOS in comparison with Autistic Disorder.

Method

A stepwise systematic PRISMA literature review was conducted by searching PubMed and Web Of Science databases to select corresponding studies.

Results

The systematic review included 81 studies comprising 6,644 children with PDD-NOS. Cross-sectional and longitudinal studies comparing PDD-NOS and AD showed that PDD-NOS corresponds to milder form of autism with less impact and less associated disorder, with the exception of schizophrenia and mood disorder.

Discussion

Our review challenges initial views of PDD-NOS, and shows the clinical relevance of this diagnosis when dealing with the margins of autism, and the de facto diversity included in the spectrum. However, in view of the many limitations of PDD-NOS (low reliability, instability through time, low acceptability), we suggest taxonomic changes in DSM-5: we introduce a new category based on three main dimensions related to socialization impairment, emotional lability and psychotic symptoms.

Conclusion

Our review argues for a distinction between AD and PDD-NOS on clinical characteristics and thus highlights the need to study the margins of autism. While the limitations of the PDD-NOS category made it irrelevant to investigate these margins from a research perspective, we believe that a multidimensional approach for mental health professionals taping socialization, emotion lability and psychotic symptoms would be interesting. Our review therefore encourage future studies to test relevant criteria for a new category and possibly identify developmental trajectories, specific interventions and treatments.

Cholesterol metabolism pathway in autism spectrum disorder: From animal models to clinical observations

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by a persistent impairment of social skills, including aspects of perception, interpretation, and response, combined with restricted and repetitive behavior. ASD is a complex and multifactorial condition, and its etiology could be attributed to genetic and environmental factors. Despite numerous clinical and experimental studies, no etiological factor, biomarker, and specific model of transmission have been consistently associated with ASD. However, an imbalance in cholesterol levels has been observed in many patients, more specifically, a condition of hypocholesterolemia, which seems to be shared between ASD and ASD-related genetic syndromes such as fragile X syndrome (FXS), Rett syndrome (RS), and Smith- Lemli-Opitz (SLO). Furthermore, it is known that alterations in cholesterol levels lead to neuroinflammation, oxidative stress, impaired myelination and synaptogenesis. Thus, the aim of this review is to discuss the cholesterol metabolic pathways in the ASD context, as well as in genetic syndromes related to ASD, through clinical observations and animal models. In fact, SLO, FXS, and RS patients display early behavioral markers of ASD followed by cholesterol disturbances. Several studies have demonstrated the role of cholesterol in psychiatric conditions and how its levels modulate brain neurodevelopment. This review suggests an important relationship between ASD pathology and cholesterol metabolism impairment; thus, some strategies could be raised - at clinical and pre-clinical levels - to explore whether cholesterol metabolism disturbance has a generally adverse effect in exacerbating the symptoms of ASD patients.

Maternal and neonatal risk factors for autism spectrum disorder: A case-control study from Egypt

Background

The prevalence of autism spectrum disorder (ASD) has been increasing steadily in Egypt and worldwide. 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 Egypt.

Methods

In this case-control study, mothers of children with ASD who were visiting Beni-Suef University Hospital in Egypt (n = 268) were compared to mothers of children without ASD attending one primary school with a kindergarten (n = 504) regarding their preconception, conception, and postconception characteristics. Data were collected using a self-administered questionnaire. The odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to investigate the possible associations between the collected data and the odds of ASD.

Results

In the multivariable-adjusted models, urban residence: OR (95% CI) = 2.33 (1.60–3.38), relative father: 2.63 (1.74–3.96), history of diabetes: 5.98 (1.99–17.97), previous abortion: 2.47 (1.20–13.38), assisted fertility: 4.01 (1.20–13.38), family history of ASD: 7.24 (2.00–26.24), multiple pregnancy: 11.60 (2.54–53.07), exposure to passive smoking during pregnancy: 2.95 (1.86–4.68), vaginal bleeding during pregnancy: 3.10 (1.44–6.67), hypertension with pregnancy: 3.64 (1.06–12.51), preterm labor: 2.64 (1.26–5.57), neonatal convulsions: 14.88 (5.01–44.20), and admission to neonatal intensive care unit 2.13: (1.21–3.74) were associated with the increased odds of ASD. On the other hand, the intake of vitamins during pregnancy: 0.09 (0.06–0.16) and C-section: 0.44 (0.27–0.70) were associated with the decreased odds of ASD.

Conclusion

This study detected several maternal and neonatal risk factors for ASD in Egyptian children.

Neonatal jaundice and autism spectrum disorder: a systematic review and meta-analysis

BACKGROUND

Two meta-analyses concluded that jaundice was associated with an increased risk of autism. We hypothesize that these findings were due to methodological limitations of the studies included. Neonatal jaundice affects many infants and risks of later morbidity may prompt physicians towards more aggressive treatment.

METHODS

To conduct a systematic literature review and a meta-analysis of the association between neonatal jaundice and autism with particular attention given to low risk of bias studies. Pubmed, Scopus, Embase, Cochrane, and Google Scholar were searched for publications until February 2019. Data was extracted by use of pre-piloted structured sheets. Low risk of bias studies were identified through predefined criteria.

RESULTS

A total of 32 studies met the inclusion criteria. The meta-analysis of six low risk of bias studies showed no association between neonatal jaundice and autism; cohort studies risk ratio 1.09, 95% CI, 0.99-1.20, case-control studies odds ratio 1.29 95% CI 0.95, 1.76. Funnel plot of all studies suggested a high risk of publication bias.

CONCLUSIONS

We found a high risk of publication bias, selection bias, and potential confounding in all studies. Based on the low risk of bias studies there was no convincing evidence to support an association between neonatal jaundice and autism.

IMPACT

Meta-analysis of data from six low risk of bias studies indicated no association between neonatal jaundice and autism spectrum disorder. Previous studies show inconsistent results, which may be explained by unadjusted confounding and selection bias. Funnel plot suggested high risk of publication bias when including all studies. There is no evidence to suggest jaundice should be treated more aggressively to prevent autism.

Autism spectrum disorder and obstetric optimality: a twin study and meta-analysis of sibling studies

BACKGROUND

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with a strong genetic basis. Recent studies have suggested that its aetiology is also influenced by environmental factors. Some of the most examined environmental factors are obstetric complications. However, the results are inconsistent.

METHODS

We aimed to explore the association between obstetric complications and autism in a population-based twin sample using the Obstetric Enquiry Scale (OES), a scale that measures the presence or absence of pre-, peri- and neonatal factors. Additionally, we report the meta-analytic results for obstetrical factors reported in previously published sibling studies.

RESULTS

Our study included 115 cases pairs and 62 controls pairs and showed that children with autism and their unaffected co-twins present significantly more obstetric complications than controls (ASD vs. controls β 1.26, CI 95% 1.11-1.40 p < .001; unaffected co-twin vs. controls β 1.20, 95% CI 1.07-1.36 p < .003). However, we did not find statistically significant differences between children with ASD and their unaffected co-twins (β .96, 95% CI 0.85-1.09, p 0.55). Meta-analysis demonstrated that maternal hypertension (RR 1.35, CI 95% 1.23-1.48), uterine bleeding (RR 1.20 CI 95% 1.01-1.42) and exposure to antibiotic during pregnancy (1.11 CI 95% 1.00-1.22) increase risk of ASD.

CONCLUSIONS

This study confirms that children with ASD and their unaffected twins show more obstetric complications than controls. However, these complications do not distinguish between ASD twins and their unaffected co-twins. In addition, the meta-analysis showed little influence of birth factors on ASD which suggests a shared familial liability for both obstetric complications and autism, rather than a causal association.

The Possibility of Intracranial Hypertension in Patients with Autism Spectrum Disorder Using Computed Tomography

Although intracranial pressure is considered to be normal in children with autism spectrum disorder (ASD), we aimed to assess whether such children may have increased intracranial pressure using noninvasive computed tomography (CT). Head CT scans of children with ASD (109 cases, male 91 and female 18, average age 4.3 years) and of children with typical development (60 cases, male 35 and female 25, average age 4.5 years) were acquired. The images were processed to map the shape of the inner skull surface. We predicted that a complex skull shape, based on a marked digital impression, would be indicative of chronically increased intracranial pressure. The data of the scans were extracted and processed to automatically establish inner and outer cranial circumferences. The circularity (reflecting inner skull shape and area) and C-ratio (ratio of inner/outer circumference) were determined and statistically analyzed. The circularity and C-ratio were significantly lower in children with ASD than in children with typical development. A lower circularity was associated with a more complex shape of the inner skull surface, which indicated the presence of intracranial hypertension. Our study suggests that children with ASD may be at a risk for chronic intracranial hypertension. Our technique incorporating the circularity and C-ratio is a useful noninvasive method for screening such patients and could impact future investigations of ASD.

An association of intrapartum synthetic oxytocin dosing and the odds of developing autism

A case-control study was performed to determine whether an association exists between exposure to synthetic oxytocin and a subsequent autism spectrum disorder diagnosis; 171 children under age 18 meeting Diagnostic and Statistical Manual of Mental Disorders (5th ed.) autism spectrum disorder criteria were compared to 171 children without autism spectrum disorder diagnosis matched by gender, birth year, gestational age, and maternal age at birth. A conditional logistic regression model was used to examine the association of clinical variables and autism spectrum disorder. Significantly elevated odds ratios for autism spectrum disorder were associated with first-time Cesarean section (odds ratio = 2.56), but not a repeat Cesarean section. Odds ratios were also significantly elevated for subjects whose mother’s body mass index was 35 or higher at birth (odds ratio = 2.34) and subjects in which the reason for delivery was categorized as “fetal indication” (odds ratio = 2.00). When controlling for these and other variables, the odds of developing autism spectrum disorder were significantly elevated in males with long duration of exposure (odds ratio = 3.48) and high cumulative dose of synthetic oxytocin (odds ratio = 2.79). No significant associations of synthetic oxytocin dosing and autism spectrum disorder were noted in female subjects. The association of elevated autism spectrum disorder odds found with high duration and high cumulative dose synthetic oxytocin in male subjects suggests the need for further investigation to fully elucidate any cause and effect relationship.

Association between neonatal jaundice and autism spectrum disorders among children: a meta-analysis

Autism spectrum disorder is a common neurodevelopmental disorder with an unknown etiology. The correlation between neonatal jaundice and the risk of developing autism spectrum disorder was investigated previously. Some studies showed significant associations, whereas others demonstrated no association. In this meta-analysis, we pooled the results of observational studies to examine the association between neonatal jaundice and the risk of autism spectrum disorder among children. We identified all studies published through April 2018 by conducting a literature search using Web of Science, PubMed, and Scopus databases as well as the reference lists of the retrieved studies. The pooled odds ratios (ORs), rate ratio (RR), and their 95% confidence intervals (CIs) were calculated as random effect estimates of association among studies. We conducted a subgroup analysis to explore any potential sources of intergroup heterogeneity. The pooled estimates of OR and RR showed a considerable correlation between neonatal jaundice and ASD among children (OR, 1.35; 95% CI, 1.02-1.68) and (RR, 1.39; 95% CI, 1.05-1.74). A larger effect size was shown in the pooled estimated crude OR than in the adjusted OR (1.75 [0.96-2.54] vs. 1.19 [1.07-1.30]). This study showed that neonatal jaundice may be associated with ASD and may increase the risk of ASD among children.

Maternal Exposures Associated with Autism Spectrum Disorder in Jamaican Children

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with poorly understood etiology. Many maternal exposures during pregnancy and breastfeeding potentially interfere with neurodevelopment. Using data from two age- and sex-matched case-control studies in Jamaica (n = 298 pairs), results of conditional logistic regression analyses suggest that maternal exposures to fever or infection (matched odds ratio (MOR) = 3.12, 95% CI 1.74-5.60), physical trauma (MOR 2.02, 95% CI 1.01-4.05), and oil-based paints (MOR 1.99, 95% CI 1.14-3.46) may be associated with ASD. Additionally, maternal exposure to oil-based paints may modify the relationship between maternal exposure to pesticides and ASD, which deepens our understanding of the association between pesticides and ASD.

Maternal diabetes and hypertensive disorders in association with autism spectrum disorder

Previous studies have shown complications of pregnancy, often examined in aggregate, to be associated with autism spectrum disorder (ASD). Results for specific complications, such as maternal diabetes and hypertension, have not been uniformly consistent and should be investigated independently in relation to ASD in a large community-based sample. The Study to Explore Early Development (SEED), a US multisite case-control study, enrolled children born in 2003-2006 at 2-5 years of age. Children were classified into three groups based on confirmation of ASD (n = 698), non-ASD developmental delay (DD; n = 887), or controls drawn from the general population (POP; n = 979). Diagnoses of any diabetes or hypertensive disorder during pregnancy were identified from prenatal medical records and maternal self-report. Logistic regression models estimated adjusted odds ratios (aOR) and confidence intervals (CI) adjusting for maternal age, race/ethnicity, education, smoking during pregnancy, and study site. Models for hypertension were additionally adjusted for parity and plurality. Among 2,564 mothers, we identified 246 (9.6%) with any diabetes and 386 (15.1%) with any hypertension in pregnancy. After adjustment for covariates, any diabetes during pregnancy was not associated with ASD (aOR = 1.10 [95% CI 0.77, 1.56]), but any hypertension was associated with ASD (aOR = 1.69 [95% CI 1.26, 2.26]). Results were similar for DD, and any diabetes (aOR = 1.29 [95% CI 0.94, 1.78]) or any hypertension (aOR = 1.71 [95% CI 1.30, 2.25]). Some pregnancy complications, such as hypertension, may play a role in autism etiology and can possibly serve as a prompt for more vigilant ASD screening efforts. Autism Res 2019, 12: 967-975. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We studied if common complications in pregnancy are associated with autism spectrum disorder (ASD) in a large sample of mothers and children. Our results show an association between conditions marked by high blood pressure and ASD, but no association with conditions marked by high blood sugar and ASD. Associations were similar for children who had a developmental disorder that was not ASD, suggesting that this relationship may not be specific to ASD.

Moderating effect of mode of delivery on the genetics of intelligence: Explorative genome-wide analyses in ALSPAC

INTRODUCTION

Intelligence is a core construct of individual differences in cognitive abilities and a strong predictor of important life outcomes. Within recent years, rates of cesarean section have substantially increased globally, though little is known about its effect on neurodevelopmental trajectories. Thus, we aimed to investigate the influence of delivery by cesarean section on the genetics of intelligence in children.

METHODS

Participants were recruited through the Avon Longitudinal Study of Parents and Children (ALSPAC). Intelligence was measured by the Wechsler Intelligence Scale for Children (WISC). Genotyping was performed using the Illumina Human Hap 550 quad genome-wide SNP genotyping platform and was followed by imputation using MACH software. Genome-wide interaction analyses were conducted using linear regression.

RESULTS

A total of 2,421 children and 2,141,747 SNPs were subjected to the genome-wide interaction analyses. No variant reached genome-wide significance. The strongest interaction was observed at rs17800861 in the GRIN2A gene (β = -3.43, 95% CI = -4.74 to -2.12, p = 2.98E-07). This variant is predicted to be located within active chromatin compartments in the hippocampus and may influence binding of the NF-kappaB transcription factor.

CONCLUSIONS

Our results may indicate that mode of delivery might have a moderating effect on genetic disposition of intelligence in children. Studies of considerable sizes (>10,000) are likely required to more robustly detect variants governing such interaction. In summary, the presented findings prompt the need for further studies aimed at increasing our understanding of effects various modes of delivery may have on health outcomes in children.

Thai parental perception of the etiology of autism spectrum disorders with an emphasis on genetics

Background: More than 90% of cases of autism spectrum disorders (ASDs) are idiopathic and are multi-factorial inheritant in etiology. Although parental perceptions of ASDs etiologies including genetics have been investigated well in western countries, there is no study regarding Asian parental perspectives on the genetic etiology of ASDs. Objectives: Examine what Thai parents perceived to be the etiology of ASDs with particular focus on the role of genetics, and analyze the correlation between demographics of parents and the perception of genetics as an etiology of ASDs. Methods: Children diagnosed with an ASD at Ramathibodi Hospital were recruited, and 328 questionnaires were mailed to their parents between February 1 and March 31, 2008. Based on 252 answers received, the perception of genetics as an etiology of ASDs was evaluated using univariate and multivariate analysis. Results: Among 252 parents, 44.0% cited genetics, 52% cited other prenatal and perinatal factors such as stress and chemical exposure during pregnancy, 33% cited postnatal factors such as child rearing, child’s viewing of television, and playing computer game as etiologies of ASDs. Parents’ education, positive family history of ASDs, and positive family history of speech delay were all significantly associated with the perception of genetics as an etiology of ASDs. Conclusions: Less than half of Thai parents cited genetics as an etiology of ASDs. This finding alerts medical professionals to spend more time and effort to educate and counsel parents.

Minor Neurological Dysfunctions (MNDs) in Autistic Children without Intellectual Disability

Background: Children with autism spectrum disorder (ASD) require neurological evaluation to detect sensory-motor impairment. This will improve understanding of brain function in children with ASD, in terms of minor neurological dysfunctions (MNDs). Methods: We compared 32 ASD children without intellectual disability (IQ ≥ 70) with 32 healthy controls. A standardized and age-specific neurological examination according to Touwen was used to detect the presence of MNDs. Particular attention was paid to severity and type of MNDs. Results: Children with ASD had significantly higher rates of MNDs compared to controls (96.9% versus 15.6%): 81.3% had simple MNDs (p < 0.0001) and 15.6% had complex MNDs (p = 0.053). The prevalence of MNDs in the ASD group was significantly higher (p < 0.0001) than controls. With respect to specific types of MNDs, children with ASD showed a wide range of fine manipulative disability, sensory deficits and choreiform dyskinesia. We also found an excess of associated movements and anomalies in coordination and balance. Conclusions: Results replicate previous findings which found delays in sensory-motor behavior in ASD pointing towards a role for prenatal, natal and neonatal risk factors in the neurodevelopmental theory of autism.

Developmental vitamin D deficiency and autism: Putative pathogenic mechanisms

Autism is a neurodevelopmental disease that presents in early life. Despite a considerable amount of studies, the neurobiological mechanisms underlying autism remain obscure. Both genetic and environmental factors are involved in the development of autism. Vitamin D deficiency is emerging as a consistently reported risk factor in children. One reason for the prominence now being given to this risk factor is that it would appear to interact with several other epidemiological risk factors for autism. Vitamin D is an active neurosteroid and plays crucial neuroprotective roles in the developing brain. It has important roles in cell proliferation and differentiation, immunomodulation, regulation of neurotransmission and steroidogenesis. Animal studies have suggested that transient prenatal vitamin D deficiency is associated with altered brain development. Here we review the potential neurobiological mechanisms linking prenatal vitamin D deficiency and autism and also discuss what future research targets must now be addressed.

Association of maternal diabetes with autism spectrum disorders in offspring: A systemic review and meta-analysis

Studies on the association of maternal diabetes with autism spectrum disorders (ASDs) in offspring provide inconsistent findings; therefore an updated and comprehensive literature review and meta-analysis is necessary to perform in order to evaluate the available evidences.After searching databases systematically, we established the inclusion criteria and selected the eligible studies. In both overall and stratified analyses, the estimated effects were synthesized dependent on the presence or absence of heterogeneity.Twelve articles involving 16 studies were included and synthesized, demonstrating a significant association of maternal diabetes with ASDs among children (relative risk [RR] = 1.48). However, high heterogeneity was observed (I = 56.3%) and publication bias was identified. In terms of the analyses on reliable evidences from case-control studies, heterogeneity and publication bias disappeared, and the risk of ASDs was increased by 62% among diabetic mothers compared with non-diabetic mothers.Maternal diabetes, especially gestational diabetes mellitus, is associated with ASDs in offspring based on a limited number of convincing case-control studies. More large-scale population-based prospective studies are still needed to draw firm conclusions.

Identification of mutations in the PI3K-AKT-mTOR signalling pathway in patients with macrocephaly and developmental delay and/or autism

Background

Macrocephaly, which is defined as a head circumference greater than or equal to + 2 standard deviations, is a feature commonly observed in children with developmental delay and/or autism spectrum disorder. Although PTEN is a well-known gene identified in patients with this syndromic presentation, other genes in the PI3K-AKT-mTOR signalling pathway have also recently been suggested to have important roles. The aim of this study is to characterise the mutation spectrum of this group of patients.

Methods

We performed whole-exome sequencing of 21 patients with macrocephaly and developmental delay/autism spectrum disorder. Sources of genomic DNA included blood, buccal mucosa and saliva. Germline mutations were validated by Sanger sequencing, whereas somatic mutations were validated by droplet digital PCR.

Results

We identified ten pathogenic/likely pathogenic mutations in PTEN (n = 4), PIK3CA (n = 3), MTOR (n = 1) and PPP2R5D (n = 2) in ten patients. An additional PTEN mutation, which was classified as variant of unknown significance, was identified in a patient with a pathogenic PTEN mutation, making him harbour bi-allelic germline PTEN mutations. Two patients harboured somatic PIK3CA mutations, and the level of somatic mosaicism in blood DNA was low. Patients who tested positive for mutations in the PI3K-AKT-mTOR pathway had a lower developmental quotient than the rest of the cohort (DQ = 62.8 vs. 76.1, p = 0.021). Their dysmorphic features were non-specific, except for macrocephaly. Among the ten patients with identified mutations, brain magnetic resonance imaging was performed in nine, all of whom showed megalencephaly.

Conclusion

We identified mutations in the PI3K-AKT-mTOR signalling pathway in nearly half of our patients with macrocephaly and developmental delay/autism spectrum disorder. These patients have subtle dysmorphic features and mild developmental issues. Clinically, patients with germline mutations are difficult to distinguish from patients with somatic mutations, and therefore, sequencing of buccal or saliva DNA is important to identify somatic mosaicism. Given the high diagnostic yield and the management implications, we suggest implementing comprehensive genetic testing in the PI3K-AKT-mTOR pathway in the clinical evaluation of patients with macrocephaly and developmental delay and/or autism spectrum disorder.

Electronic supplementary material

The online version of this article (10.1186/s13229-017-0182-4) contains supplementary material, which is available to authorized users.

Maternal smoking and autism spectrum disorder: meta-analysis with population smoking metrics as moderators

While exposure to nicotine during developmental periods can significantly affect brain development, studies examining the association between maternal smoking and autism spectrum disorder (ASD) in offspring have produced conflicting findings, and prior meta-analyses have found no significant association. Our meta-analysis used a novel approach of investigating population-level smoking metrics as moderators. The main meta-analysis, with 22 observational studies comprising 795,632 cases and 1,829,256 control participants, used a random-effects model to find no significant association between maternal smoking during pregnancy and ASD in offspring (pooled odds ratio (OR) = 1.16, 95% CI: 0.97–1.40). However, meta-regression analyses with moderators were significant when we matched pooled ORs with adult male smoking prevalence (z = 2.55, p = 0.01) in each country, using World Health Organization data. Our study shows that using population-level smoking metrics uncovers significant relationships between maternal smoking and ASD risk. Correlational analyses show that male smoking prevalence approximates secondhand smoke exposure. While we cannot exclude the possibility that our findings reflect the role of paternal or postnatal nicotine exposure, as opposed to maternal or in utero nicotine exposure, this study underlines the importance of investigating paternal and secondhand smoking in addition to maternal smoking in ASD.

Human Birth Weight and Reproductive Immunology: Testing for Interactions between Maternal and Offspring KIR and HLA-C Genes

BACKGROUND/AIMS

Maternal and offspring cell contact at the site of placentation presents a plausible setting for maternal-fetal genotype (MFG) interactions affecting fetal growth. We test hypotheses regarding killer cell immunoglobulin-like receptor (KIR) and HLA-C MFG effects on human birth weight by extending the quantitative MFG (QMFG) test.

METHODS

Until recently, association testing for MFG interactions had limited applications. To improve the ability to test for these interactions, we developed the extended QMFG test, a linear mixed-effect model that can use multi-locus genotype data from families.

RESULTS

We demonstrate the extended QMFG test's statistical properties. We also show that if an offspring-only model is fit when MFG effects exist, associations can be missed or misattributed. Furthermore, imprecisely modeling the effects of both KIR and HLA-C could result in a failure to replicate if these loci's allele frequencies differ among populations. To further illustrate the extended QMFG test's advantages, we apply the extended QMFG test to a UK cohort study and the Norwegian Mother and Child Cohort (MoBa) study.

CONCLUSION

We find a significant KIR-HLA-C interaction effect on birth weight. More generally, the QMFG test can detect genetic associations that may be missed by standard genome-wide association studies for quantitative traits.

Environmental factors influencing the risk of autism

Autism is a developmental disability with age of onset in childhood (under 3 years old), which is characterized by definite impairments in social interactions, abnormalities in speech, and stereotyped pattern of behaviors. Due to the progress of autism in recent decades, a wide range of studies have been done to identify the etiological factors of autism. It has been found that genetic and environmental factors are both involved in autism pathogenesis. Hence, in this review article, a set of environmental factors involved in the occurrence of autism has been collected, and finally, some practical recommendations for reduction of the risk of this devastating disease in children are represented.

Risk of Autism Associated With Hyperbilirubinemia and Phototherapy

OBJECTIVE

Whether neonatal hyperbilirubinemia and/or phototherapy increase the risk of autism spectrum disorder (ASD) is unclear. We sought to quantify the risk of ASD associated with elevated total serum bilirubin (TSB) levels and with phototherapy.

METHODS

In a retrospective cohort study of 525 409 infants born at ≥35 weeks' gestation in 15 Kaiser Permanente Northern California (KPNC) hospitals, 1995-2011, we obtained all TSB levels and determined which infants received phototherapy. From the KPNC Autism Registry, we identified patients with ASD diagnosed at a KPNC Autism Center, by a clinical specialist, or by a pediatrician. We calculated Cox proportional hazard ratios (HRs) for time to diagnosis of ASD, adjusting for confounding factors.

RESULTS

Among infants in the birth cohort, 2% had at least 1 TSB level ≥20 mg/dL, and 8% received phototherapy. The rate of ASD was 13 per 1000 births. Crude analyses revealed an association between TSB ≥20 and ASD (relative risk: 1.4; 95% confidence interval [CI]: 1.1-1.6), and between phototherapy and ASD (relative risk: 1.7; 95% CI: 1.5-1.8). After adjusting for confounders, TSB ≥20 (HR: 1.09; 95% CI: 0.89-1.35) and phototherapy (HR: 1.10; 95% CI: 0.98-1.24) were no longer significantly associated with ASD. Independent risk factors for ASD included maternal and paternal age; maternal and paternal higher education; male sex; birth weight <2500 g or ≥4200 g; and later year of birth.

CONCLUSIONS

After adjustment for the effects of sociodemographic factors and birth weight, neither hyperbilirubinemia nor phototherapy was an independent risk factor for ASD.

Is the Risk of Autism in Younger Siblings of Affected Children Moderated by Sex, Race/Ethnicity, or Gestational Age?

OBJECTIVE

To evaluate the recurrence risk of autism spectrum disorders (ASD) in younger siblings of affected children and determine how it is modified by race/ethnicity and sex.

METHOD

Medical records of children born in a large health maintenance organization (Kaiser Permanent Southern California) hospitals from January 1, 2001, through December 31, 2010, and who remained in our system until 2 to 11 years of age were used to assess the risk of recurrence of ASD in younger siblings. Children born at <28 or >42 weeks gestation, multiple births, or those who were not active members for ≥3 months were excluded. ASD diagnosis was ascertained from DSM-IV codes, and the magnitude of the association was estimated using adjusted relative risks (aRRs).

RESULTS

Among eligible younger siblings, 592 (1.11%) had the diagnosis of ASD. The ASD rates were 11.30% and 0.92% for younger siblings of older affected and unaffected siblings, respectively (aRR: 14.27; 95% confidence interval, 11.41-17.83). This association remained after adjusting for potential confounding factors. Race/ethnicity- and gestational age-specific analyses revealed a positive association of similar magnitude across groups. Risk remained higher in younger boys than girls regardless of the sex of affected older siblings.

CONCLUSION

The findings of this study suggest that the risk of ASD in younger siblings is higher if the older sibling has ASD. The risk of ASD in younger siblings of older affected siblings was comparable across gestational age at birth and child's race/ethnicity groups. However, risk remains higher for boys. This study contributes to a better understanding of the influence of race/ethnicity, sex, and gestational age at birth in identifying children at higher risk of ASD.

Association of Labor Induction With Offspring Risk of Autism Spectrum Disorders

IMPORTANCE

Induction of labor is a frequently performed obstetrical intervention. It would thus be of great concern if reported associations between labor induction and offspring risk of autism spectrum disorders (ASD) reflected causal influence.

OBJECTIVE

To assess the associations of labor induction with ASD, comparing differentially exposed relatives (siblings and cousins discordant for induction).

DESIGN, SETTING, AND PARTICIPANTS

Follow-up of all live births in Sweden between 1992 and 2005, defined in the Medical Birth Register. The register was linked to population registers of familial relations, inpatient and outpatient visits, and education records. Diagnoses of ASD were from 2001 through 2013, and data were analyzed in the 2015-2016 year.

EXPOSURES

Induction of labor.

MAIN OUTCOMES AND MEASURES

Autism spectrum disorders identified by diagnoses from inpatient and outpatient records between 2001 and 2013. Hazard ratios (HRs) quantified the association between labor induction and offspring ASD. In addition to considering a wide range of measured confounders, comparison of exposure-discordant births to the same woman allowed additional control for all unmeasured factors shared by siblings.

RESULTS

The full cohort included 1 362 950 births, of which 22 077 offspring (1.6%) were diagnosed with ASD by ages 8 years through 21 years. In conventional models of the full cohort, associations between labor induction and offspring ASD were attenuated but remained statistically significant after adjustment for measured potential confounders (HR, 1.19; 95% CI, 1.13-1.24). When comparison was made within siblings whose births were discordant with respect to induction, thus accounting for all environmental and genetic factors shared by siblings, labor induction was no longer associated with offspring ASD (HR, 0.99; 95% CI, 0.88-1.10).

CONCLUSIONS AND RELEVANCE

In this nationwide sample of live births we observed no association between induction of labor and offspring ASD within sibling comparison. Our findings suggest that concern for ASD should not factor into the clinical decision about whether to induce labor.

Increased Risk of Autism Development in Children Whose Mothers Experienced Birth Complications or Received Labor and Delivery Drugs

Autism spectrum disorder (ASD) is a perplexing and pervasive developmental disorder characterized by social difficulties, communicative deficits, and repetitive behavior. The increased rate of ASD diagnosis has raised questions concerning the genetic and environmental factors contributing to the development of this disorder; meanwhile, the cause of ASD remains unknown. This study surveyed mothers of ASD and non-ASD children to determine possible effects of labor and delivery (L&D) drugs on the development of ASD. The survey was administered to mothers; however, the results were analyzed by child, as the study focused on the development of autism. Furthermore, an independent ASD dataset from the Southwest Autism Research and Resource Center was analyzed and compared. Indeed, L&D drugs are associated with ASD (p = .039). Moreover, the Southwest Autism Research and Resource Center dataset shows that the labor induction drug, Pitocin, is significantly associated with ASD (p = .004). We also observed a synergistic effect between administrations of L&D drugs and experiencing a birth complication, in which both obstetrics factors occurring together increased the likelihood of the fetus developing ASD later in life (p = .0003). The present study shows the possible effects of L&D drugs, such as Pitocin labor-inducing and analgesic drugs, on children and ASD.

Adverse Prenatal, Perinatal and Neonatal Experiences in Children with Anxiety Disorders

This study examined the incidence of adverse prenatal, perinatal, and neonatal experiences amongst children with anxiety disorders, and the relationship to clinical symptomology and functional impairment in treatment-seeking children (N = 107) with a primary anxiety disorder. Anxious children had higher rates of reported maternal prescription medication use during pregnancy, maternal smoking and illness during pregnancy and neonatal complications (including neonatal intensive care and feeding issues) compared with population base rates and non-affected children. Almost one-third had early problems with sleep. Developmental problems were common with more than half having at least one area of delay. More than three quarters of anxious children had a first-degree family member with a psychiatric history. There were several associations between neonatal complications and subsequent clinical symptomology, including attention deficit hyperactivity disorder and depressive comorbidity, anxiety severity and functional impairment. Findings suggest higher rates of perinatal complications in anxious children.

Maternal Smoking and Autism Spectrum Disorder: A Meta-analysis

We conducted a meta-analysis of 15 studies on maternal prenatal smoking and ASD risk in offspring. Using a random-effects model, we found no evidence of an association (summary OR 1.02, 95% CI 0.93-1.12). Stratifying by study design, birth year, type of healthcare system, and adjustment for socioeconomic status or psychiatric history did not alter the findings. There was evidence that ascertaining exposure at the time of birth produced a lower summary OR than when this information was gathered after birth. There was no evidence of publication bias. Non-differential exposure misclassification was shown to have the potential for negligible influence on the results. We found no evidence to support a measurable association between maternal prenatal smoking and ASD in offspring.

The Quantitative-MFG Test: A Linear Mixed Effect Model to Detect Maternal-Offspring Gene Interactions

Maternal-offspring gene interactions, aka maternal-fetal genotype (MFG) incompatibilities, are neglected in complex diseases and quantitative trait studies. They are implicated in birth to adult onset diseases but there are limited ways to investigate their influence on quantitative traits. We present the quantitative-MFG (QMFG) test, a linear mixed model where maternal and offspring genotypes are fixed effects and residual correlations between family members are random effects. The QMFG handles families of any size, common or general scenarios of MFG incompatibility, and additional covariates. We develop likelihood ratio tests (LRTs) and rapid score tests and show they provide correct inference. In addition, the LRT's alternative model provides unbiased parameter estimates. We show that testing the association of SNPs by fitting a standard model, which only considers the offspring genotypes, has very low power or can lead to incorrect conclusions. We also show that offspring genetic effects are missed if the MFG modeling assumptions are too restrictive. With genome-wide association study data from the San Antonio Family Heart Study, we demonstrate that the QMFG score test is an effective and rapid screening tool. The QMFG test therefore has important potential to identify pathways of complex diseases for which the genetic etiology remains to be discovered.

Association of Autism Spectrum Disorders With Neonatal Hyperbilirubinemia

Autism spectrum disorders (ASD) are a common neurodevelopmental disorder of unknown etiology. Studies suggest a link between autism and neonatal jaundice. A 1:3 matched case–control study was conducted with children enrolled in the Military Health System born between October 2002 and September 2009. Diagnostic and procedure codes were used for identifying ASD and hyperbilirubinemia. Two definitions for hyperbilirubinemia were evaluated: an inpatient admission with a diagnosis of jaundice and treatment with phototherapy. A total of 2917 children with ASD and 8751 matched controls were included in the study. After adjustment, there remained an association between ASD in children and an admission with a diagnosis of jaundice (odds ratio = 1.18; 95% confidence interval = 1.06-1.31; P = .001) and phototherapy treatment (odds ratio = 1.33; 95% confidence interval = 1.04-1.69; P = .008). Children who develop ASD are more likely to have an admission with a diagnosis of jaundice in the neonatal period and more likely to require treatment for this jaundice.

Prenatal Infection and Autism Spectrum Disorders in Childhood: A Population-Based Case-Control Study in Taiwan

BACKGROUND

Infection in pregnancy has long been linked with negative postnatal development and health. This study aims to assess the association between prenatal infections and autism spectrum disorders (ASDs) across three trimesters and to probe possible sex heterogeneity in such link.

METHOD

A total of 4184 children with incident ASDs and 16,734 matched children were identified from the 2000-2007 National Health Insurance Research Database. For each child, information pertaining to the mother's infection during pregnancy, sociodemographics, and medical history was retrieved from healthcare records. Conditional logistic analyses were carried out to estimate the strength of associations with adjustment for multiple comparisons.

RESULT

Pooled analyses demonstrated that having two or more outpatient visits for genital infection [adjusted odds ratio (aOR): 1.34; 95% confidence interval (95% CI) 1.12, 1.60; false discovery rate (FDR) < 0.01] and bacterial infection (aOR: 1.24; 95% CI 1.06, 1.43; FDR < 0.05) in the third trimester were slightly associated with increased risk of ASDs. No statistically significant sex differences were found.

CONCLUSION

The present study contributes updated population-based evidence about the connection between prenatal infection and ASDs. Potential effect of bacterial and genital tract infections during the third trimester on risk of ASDs warrants further exploration.

Prenatal factors associated with autism spectrum disorder (ASD)

Autism spectrum disorder (ASD) affecting about 1% of all children is associated, in addition to complex genetic factors, with a variety of prenatal, perinatal and postnatal etiologies. We discuss the known associated prenatal factors affecting the fetus throughout pregnancy; whenever relevant, also summarize some animal data. Among the maternal diseases in pregnancy associated with ASD are pregestational and/or gestational diabetes mellitus (PGDM, GDM), maternal infections (i.e. rubella, cytomegalovirus (CMV)), prolonged fever and maternal inflammation, which cause changes in a variety of inflammatory cytokines. Among the drugs are valproic acid, thalidomide, and possibly misoprostol and serotonin reuptake inhibitors (SSRIs). Associations were described with ethanol, and possibly cocaine, heavy metals heavy smoking and Folic acid deficiency. Heavy exposure to pesticides and air pollution during pregnancy was recently associated with ASD. We need more epidemiologic data to establish many of these associations; if proven, they might be promising avenues for prevention.

Educational and therapeutic behavioral approaches to providing dental care for patients with Autism Spectrum Disorder

PURPOSE

Autism Spectrum Disorder (ASD) is a condition which most dentists will encounter in their practices. Contemporary educational and behavioral approaches may facilitate successful dental care.

METHODS

A literature review was conducted for relevant information on dental care for children with ASD.

RESULTS

Educational principles used for children with ASD can be applied in the dental setting. Examples include: parent involvement in identifying strengths, sensitivities, and goal setting; using stories or video modeling in advance of the appointment; dividing dental treatment into sequential components; and modification of the environment to minimize sensory triggers. Patients with ASD are more capable of tolerating procedures that they are familiar with, and therefore should be exposed to new environments and stimuli in small incremental steps.

CONCLUSIONS

By taking time to understand children with ASD as individuals and employing principles of learning, clinicians can provide high quality dental care for the majority of patients with ASD.

ACOG Committee Opinion no. 597: Committee on Obstetric Practice: Labor induction or augmentation and autism

Functional oxytocin deficiency and a faulty oxytocin signaling pathway have been observed in conjunction with autism spectrum disorder (ASD). Because exogenous synthetic oxytocin commonly is administered for labor induction and augmentation, some have hypothesized that synthetic oxytocin used for these purposes may alter fetal oxytocin receptors and predispose exposed offspring to ASD. However, current evidence does not identify a causal relationship between labor induction or augmentation in general, or oxytocin labor induction specifically, and autism or ASD. Recognizing the limitations of available study design, conflicting data, and the potential consequences of limiting labor induction and augmentation, the Committee on Obstetric Practice recommends against a change in current guidance regarding counseling and indications for and methods of labor induction and augmentation.

Perinatal and background risk factors for childhood autism in central China

Perinatal and background risk factors for autism were identified in a cohort of autistic children in Zhengzhou, China, to formulate preventative and treatment strategies for high-risk families. In this case-control study, children were screened for suspected autism using the Autism Behavior Checklist (ABC) and diagnosed according to DSM-IV and the Childhood Autism Rating Scale (CARS). We collected perinatal histories and clinical data of 286 confirmed autistic children treated at the Third Affiliated Hospital Children׳s Psychological Clinic of Zhengzhou University from 2011 to 2013. The control group consisted of 286 healthy children from area kindergartens. Maternal age>30 years, parental introversion as measured by the Eysenck Personality Questionnaire, low level of parental education, smoking, abortion threat, pregnancy complications, maternal illness during pregnancy, maternal mental health, family history of mental illness, neonatal jaundice, birth asphyxia, premature rupture of the fetal membrane, and gestational age<37 weeks were significantly higher in the autism group. These factors were significantly correlated with behavioral symptoms as measured by ABC scores (Kendall rank correlation). Birth asphyxia, neonatal jaundice, maternal age, parental introversion, family history of mental illness, abortion threat, premature delivery, and smoking were identified as independent risk factors by multivariate logistic regression.

DSM-5 ASD moves forward into the past

The fifth edition of the diagnostic and statistical manual of mental disorders (DSM-5) (APA in diagnostic and statistical manual of mental disorders, Author, Washington, 2013) has decided to merge the subtypes of pervasive developmental disorders into a single category of autism spectrum disorder (ASD) on the assumption that they cannot be reliably differentiated from one another. The purpose of this review is to analyze the basis of this assumption by examining the comparative studies between Asperger's disorder (AsD) and autistic disorder (AD), and between pervasive developmental disorder not otherwise specified (PDDNOS) and AD. In all, 125 studies compared AsD with AD. Of these, 30 studies concluded that AsD and AD were similar conditions while 95 studies found quantitative and qualitative differences between them. Likewise, 37 studies compared PDDNOS with AD. Nine of these concluded that PDDNOS did not differ significantly from AD while 28 reported quantitative and qualitative differences between them. Taken together, these findings do not support the conceptualization of AD, AsD and PDDNOS as a single category of ASD. Irrespective of the changes proposed by the DSM-5, future research and clinical practice will continue to find ways to meaningfully subtype the ASD.

Pre- and perinatal risk factors for autism spectrum disorder in a New Jersey cohort

This study evaluated the prevalence of pre- and perinatal risk factors in a cohort of children with autism spectrum disorders compared with the New Jersey population. Our cohort included 268 individuals with an autism spectrum disorder. Birth histories were obtained by a self-administered questionnaire. The autism spectrum disorders cohort rates of 7 perinatal risk factors were significantly higher than New Jersey state rates: mother's age 35 years or older, low birth weight, multiple gestation, prematurity, vaginal bleeding, prolonged labor, and hypoxia. Analysis of clustering of risk factors in the cohort showed no significant differences across maternal and paternal age groups. Older mothers in the cohort had a higher risk of infant hypoxia. Multiple risk factors during pregnancy appear to be associated with a higher risk of autism spectrum disorders in offspring, supporting the hypothesis that environmental influences in conjunction with genetics contribute to the causes of autism spectrum disorders.

Environmental chemical exposures and autism spectrum disorders: a review of the epidemiological evidence

In the past decade, the number of epidemiological publications addressing environmental chemical exposures and autism has grown tremendously. These studies are important because it is now understood that environmental factors play a larger role in causing autism than previously thought and because they address modifiable risk factors that may open up avenues for the primary prevention of the disability associated with autism. In this review, we covered studies of autism and estimates of exposure to tobacco, air pollutants, volatile organic compounds and solvents, metals (from air, occupation, diet, dental amalgams, and thimerosal-containing vaccines), pesticides, and organic endocrine-disrupting compounds such as flame retardants, non-stick chemicals, phthalates, and bisphenol A. We included studies that had individual-level data on autism, exposure measures pertaining to pregnancy or the 1st year of life, valid comparison groups, control for confounders, and adequate sample sizes. Despite the inherent error in the measurement of many of these environmental exposures, which is likely to attenuate observed associations, some environmental exposures showed associations with autism, especially traffic-related air pollutants, some metals, and several pesticides, with suggestive trends for some volatile organic compounds (e.g., methylene chloride, trichloroethylene, and styrene) and phthalates. Whether any of these play a causal role requires further study. Given the limited scope of these publications, other environmental chemicals cannot be ruled out, but have not yet been adequately studied. Future research that addresses these and additional environmental chemicals, including their most common routes of exposures, with accurate exposure measurement pertaining to several developmental windows, is essential to guide efforts for the prevention of the neurodevelopmental damage that manifests in autism symptoms.

Maternal diabetes and the risk of autism spectrum disorders in the offspring: a systematic review and meta-analysis

We performed a systematic literature search regarding maternal diabetes before and during pregnancy and the risk of autism spectrum disorders (ASD) in the offspring. Of the 178 potentially relevant articles, 12 articles including three cohort studies and nine case-control studies were included in the meta-analysis. Both the meta-analyses of cohort studies and case-control studies showed significant associations. The pooled relative risk and 95% confidence interval (CI) among cohort studies was 1.48 (1.25-1.75, p < 0.001). For case-control studies, the pooled odds ratio and 95% CI was 1.72 (1.24-2.41, p = 0.001). No indication of significant heterogeneity across studies or publication bias was observed. In conclusion, maternal diabetes was significantly associated with a greater risk of ASD in the offspring.

Are Attributes of Pregnancy and the Delivery Room Experience Related to Development of Autism? A Review of the Perinatal and Labor Risk Factors and Autism

Autism is a neurodevelopmental disorder marked by severe deficits in social communication and interactions. It is a complex condition that lacks an established preventive method, warranting a need for research to identify possible environmental triggers. The identification of external factors particularly perinatal risk factors forms the initial critical step in preventing and alleviating risks. We conducted a literature review to assess evidence suggested in the worldwide literature. Perinatal risk factors that have a suggested association include β2 adrenergic receptor agonists, labor induction and augmentation, maternal infection and disease (i.e., antiphospholipid syndrome), antiepileptic drugs, cocaine use, and oral supplements. Smoking has not been found to have a direct association. Pollutants, selective serotonin reuptake inhibitors, artificial insemination, and fertility medications may have a link, but results are often conflicted. Factors related to the delivery room experience may be associated with meconium aspiration syndrome, birth weight, and labor time. Several risk factors during the pregnancy and labor periods have been associated with autism; yet further studies with large populations are needed to establish definitive associations. The fact that several risk factors during the prenatal and labor periods are implicated in autism should prompt the medical community to focus on the pregnancy and labor periods as preventive measures to curb the incidence of autism.

Is oxytocin a maternal-foetal signalling molecule at birth? Implications for development

The neuropeptide oxytocin was first noted for its capacity to promote uterine contractions and facilitate delivery in mammals. The study of oxytocin has grown to include awareness that this peptide is a neuromodulator with broad effects throughout the body. Accumulating evidence suggests that oxytocin is a powerful signal to the foetus, helping to prepare the offspring for the extrauterine environment. Concurrently, the use of exogenous oxytocin or other drugs to manipulate labour has become common practice. The use of oxytocin to expedite labour and minimise blood loss improves both infant and maternal survival under some conditions. However, further investigations are needed to assess the developmental consequences of changes in oxytocin, such as those associated with pre-eclampsia or obstetric manipulations associated with birth. This review focuses on the role of endogenous and exogenous oxytocin as a neurochemical signal to the foetal nervous system. We also examine the possible developmental consequences, including those associated with autism spectrum disorder, that arise from exogenous oxytocin supplementation during labour.

Women's posttraumatic stress symptoms and autism spectrum disorder in their children

Maternal posttraumatic stress disorder (PTSD) may be associated with autism spectrum disorder (ASD) in offspring through multiple pathways: maternal stress may affect the fetus; ASD in children may increase risk of PTSD in mothers; and the two disorders may share genetic risk. Understanding whether maternal PTSD is associated with child's ASD is important for clinicians treating children with ASD, as PTSD in parents is associated with poorer family functioning. We examined the association of maternal PTSD with offspring ASD in a large US cohort (N ASD cases = 413, N controls = 42,868). Mother's PTSD symptoms were strongly associated with child's ASD (RR 4-5 PTSD symptoms=1.98, 95% CI=1.39, 2.81; RR 6-7 symptoms=2.89, 95% CI=2.00, 4.18). Clinicians treating persons with ASD should be aware of elevated risk of PTSD in the mother. Genetic studies should investigate PTSD risk alleles in relation to ASD.

The prenatal, perinatal and neonatal risk factors for children's developmental coordination disorder: a population study in mainland China

We initially conducted a population-based study on developmental coordination disorder (DCD) in mainland China to explore the prenatal, perinatal and neonatal risk factors on DCD. A total of 4001 children were selected from 160 classes in 15 public nursery schools. The Movement Assessment Battery for Children-Second Edition (MABC-2) was used to assess the children's motor function. Crude and adjusted odds ratios were estimated to determine the strength of association using a multilevel logistic regression model with a random intercept. Three hundred and thirty children out of 4001 subjects met the DSM-IV criteria for DCD, and 3671 children were non-DCD. Maternal age, threatened abortion, fetal distress during labor, preterm birth, chronic lung disease and newborn pathological jaundice were related with DCD (OR=1.72, 2.72, 9.14, 5.17, 1.43, and 2.54, respectively, each p<0.05). Considered collectively, these risk factors may provide clues to an etiology of DCD. Additionally, the practitioners of maternity and child health care should improve the assessment and monitoring of the prenatal, perinatal and neonatal risk factors for DCD.

Obstetric risk factors and autism spectrum disorders in Finland

OBJECTIVE

To examine the relationship between obstetric risk factors and childhood autism, Asperger syndrome, and other pervasive developmental disorders (PDDs).

STUDY DESIGN

Registry-based case-control study from all singleton births in Finland from 1990-2005. Cases with childhood autism, Asperger syndrome, or PDD (n = 4713) were identified from the Finnish Hospital Discharge Register. Each case was matched to 4 controls on sex, date of birth, and place of birth. Information on obstetric risk factors was from the Finnish Medical Birth Register. Conditional logistic regression models were used for statistical analyses.

RESULTS

When adjusted with confounders, childhood autism was associated with maternal high blood pressure (OR 1.49, 95% CI 1.1-2.1, P = .018), Apgar scores less than 7 (1 minute, OR 1.46, 95% CI 1.1-2.0, P = .021), and neonatal treatment with monitoring (OR 1.40, 95% CI 1.02-1.9, P = .038). PDD was associated with induced labor (OR 1.25 95% CI 1.1-1.5, P = .007), planned cesarean delivery (OR 1.34, 95% CI 1.1-1.7, P = .009), 1-minute Apgar scores 7-8 ( OR 1.22, 95% CI 1.1-1.4, P = .008) and less than 7 (OR 1.34, 95% CI 1.03-1.8, P = .032), and neonatal intensive care unit treatment (OR 1.52, 95% CI 1.2-2.0, P = .003). Asperger syndrome was associated only with 1-minute Apgar scores 7-8 (OR 1.19, 95% CI 1.03-1.4, P = .018).

CONCLUSIONS

Low Apgar scores as well as conditions requiring neonatal special follow-up are important risk factors for childhood autism and PDD. These findings suggest that fetal distress is a potential risk factor for these disorders, but not for Asperger syndrome.

Low maternal progesterone may contribute to both obstetrical complications and autism

Studies show increased autism risk among children born to mothers experiencing obstetrical complications. Although this is usually interpreted as suggesting that the obstetrical complications could be causing autism, it is possible that a single factor could be responsible for both complications and autism. We hypothesized that low levels of the hormone progesterone is responsible since it is supplied to the fetus maternally and does not only support pregnancy but also promotes brain development. Following a review of the literature, we report findings from a survey of mothers of autistic children (n=86) compared to mothers of typically-developing children (n=88) regarding obstetrical histories, including five obstetrical risk factors indicative of low progesterone. Using this analysis, the ASD group had significantly more risk factors than controls (1.21 ± 0.09 vs. 0.76 ± 0.08, p<.0001), suggesting low progesterone. Thus, results suggest that low progesterone may be responsible for both obstetrical complications and brain changes associated with autism and that progesterone levels should be routinely monitored in at-risk pregnancies. Our hypothesis also suggests that ensuring adequate levels of progesterone may decrease the likelihood of autism.