Maternal stress and perinatal features in autism and attention deficit/hyperactivity disorder

A case-control study on pre-, peri-, and neonatal risk factors associated with autism spectrum disorder among Armenian children

We aimed to investigate the role of pre-, peri- and neonatal risk factors in the development of autism spectrum disorder (ASD) among Armenian children with the goal of detecting and addressing modifiable risk factors to reduce ASD incidence. For this purpose a retrospective case-control study using a random proportional sample of Armenian children with ASD to assess associations between various factors and ASD was conducted. The study was approved by the local ethical committee, and parental written consent was obtained. A total of 168 children with ASD and 329 controls were included in the analysis. Multivariable logistic regression analysis revealed that male gender, maternal weight gain, use of MgB6, self-reported stress during the pregnancy, pregnancy with complications, as well as use of labor-inducing drugs were associated with a significant increase in the odds of ASD, whereas Duphaston use during pregnancy, the longer interpregnancy interval and birth height were associated with decreased odds of ASD. These findings are pertinent as many identified factors may be preventable or modifiable, underscoring the importance of timely and appropriate public health strategies aimed at disease prevention in pregnant women to reduce ASD incidence.

A Systematic Review and Meta-analysis of Prenatal, Birth, and Postnatal Factors Associated with Attention-Deficit/Hyperactivity Disorder in Children

Previous studies have shown mixed results on the relationship between prenatal, birth, and postnatal ("pregnancy-related") risk factors and attention-deficit/hyperactivity disorder (ADHD). We conducted meta-analyses to identify potentially modifiable pregnancy-related factors associated with ADHD. A comprehensive search of PubMed, Web of Science, and EMBASE in 2014, followed by an updated search in January 2021, identified 69 articles published in English on pregnancy-related risk factors and ADHD for inclusion. Risk factors were included in the meta-analysis if at least three effect sizes with clear pregnancy-related risk factor exposure were identified. Pooled effect sizes were calculated for ADHD overall, ADHD diagnosis, inattention, and hyperactivity/impulsivity. Odds ratios (OR) were calculated for dichotomous measures and correlation coefficients (CC) for continuous measures. Prenatal factors (pre-pregnancy weight, preeclampsia, pregnancy complications, elevated testosterone exposure), and postnatal factors (Apgar score, neonatal illness, no breastfeeding) were positively associated with ADHD overall; the findings for ADHD diagnosis were similar with the exception that there were too few effect sizes available to examine pre-pregnancy weight and lack of breastfeeding. Prenatal testosterone was significantly associated with inattention and hyperactivity/impulsivity. Effect sizes were generally small (range 1.1-1.6 ORs, -0.16-0.11 CCs). Risk factors occurring at the time of birth (perinatal asphyxia, labor complications, mode of delivery) were not significantly associated with ADHD. A better understanding of factors that are consistently associated with ADHD may inform future prevention strategies. The findings reported here suggest that prenatal and postnatal factors may serve as potential targets for preventing or mitigating the symptoms of ADHD.

A Systematic Review and Meta-analysis of Parental Depression, Antidepressant Usage, Antisocial Personality Disorder, and Stress and Anxiety as Risk Factors for Attention-Deficit/Hyperactivity Disorder (ADHD) in Children

Poor parental mental health and stress have been associated with children's mental disorders, including attention-deficit/hyperactivity disorder (ADHD), through social, genetic, and neurobiological pathways. To determine the strength of the associations between parental mental health and child ADHD, we conducted a set of meta-analyses to examine the association of parent mental health indicators (e.g., parental depression, antidepressant usage, antisocial personality disorder, and stress and anxiety) with subsequent ADHD outcomes in children. Eligible ADHD outcomes included diagnosis or symptoms. Fifty-eight articles published from 1980 to 2019 were included. We calculated pooled effect sizes, accounting for each study's conditional variance, separately for test statistics based on ADHD as a dichotomous (e.g., diagnosis or clinical cutoffs) or continuous measurement (e.g., symptoms of ADHD subtypes of inattentiveness and hyperactivity/impulsivity). Parental stress and parental depression were significantly associated with increased risk for ADHD overall and both symptoms and diagnosis. Specifically, maternal stress and anxiety, maternal prenatal stress, maternal depression, maternal post-partum depression, and paternal depression were positively associated with ADHD. In addition, parental depression was associated with symptoms of ADHD inattentive and hyperactive/impulsive subtypes. Parental antisocial personality disorder was also positively associated with ADHD overall and specifically ADHD diagnosis. Prenatal antidepressant usage was associated with ADHD when measured dichotomously only. These findings raise the possibility that prevention strategies promoting parental mental health and addressing parental stress could have the potential for positive long-term impacts on child health, well-being, and behavioral outcomes.

Prenatal maternal stress, breastfeeding and offspring ADHD symptoms

There is increasing evidence to suggest that environmental factors are associated with ADHD, but results regarding prenatal maternal stress, unwanted pregnancy, breastfeeding, and ADHD in children are controversial and few prospective studies have been conducted. Using prospectively collected data from the Northern Finland Birth Cohort 1986 (n = 7,910) we studied potential risk factors for ADHD symptoms at 8 and 16 years of age, including prenatal maternal stress and unwanted pregnancy, and protective factors including the duration of breastfeeding. Prenatal stress was associated with an increased risk of ADHD symptoms at the age of 16 (OR = 1.95, 95% CI: 1.34-2.80) and an unwanted pregnancy correlated with hyperactivity symptoms in the offspring at the age of 8 (OR = 2.08, 95% CI: 1.55-2.77). We did not find an association between prenatal maternal stress and hyperactivity symptoms in the offspring at the age of 8 (OR = 0.87, 95% CI: 0.69-1.08) or with unwanted pregnancy and ADHD symptoms at the age of 16 (OR = 1.13, 95% CI: 0.57-2.02). In relation to breastfeeding, over three months of exclusive breastfeeding was associated with lower hyperactivity symptoms in the 8-year follow-up (OR = 0.65, 95% CI: 0.46-0.92) and there was evidence of same kind of relationship concerning non-exclusive breastfeeding, but the association was not statistically significant (OR = 0.76, 95% CI: 0.54-1.06). In 16-year follow-up, under six months of non-exclusive breastfeeding showed an association with ADHD symptoms (OR = 0.68, 95% CI: 0.48-0.95) while exclusive breastfeeding did not (OR = 1.00, 95% CI: 0.66-1.55). In conclusion, our findings suggest that prenatal maternal stress increases the risk of more severe forms of ADHD symptoms in the offspring and breastfeeding can protect against such symptoms at the ages of 8 and 16.

Maternal Migration, Prenatal Stress and Child Autistic Traits: Insights From a Population-Based Cohort Study

OBJECTIVE

There is emerging evidence for an increased prevalence of autism in children of mothers with a migration background. To date, the mechanisms underlying this relationship are poorly understood. We investigated whether prenatal stress exposure mediates the association between maternal migration and child autistic traits, assessing first- and second-generation migrant mothers in the Netherlands and their children.

METHOD

The study was embedded in the prospective population-based Generation R cohort. Of the 4,727 participants, 1,773 mothers (38%) had a migration background. Prenatal stress was assessed using questionnaires related to stressful life events, family functioning, self-esteem, long-lasting difficulties, symptoms of psychopathology, social support, and perceived discrimination. Autistic traits were measured at age 6 years with the parent-reported Social Responsiveness Scale exclusively. Longitudinal multiple mediation analyses were performed. Analyses were stratified by migration origin (Europe and outside Europe) because of differences in migration characteristics.

RESULTS

Maternal migration background was associated with more experienced stress and with higher child autistic trait scores (Europe: mean = 0.42, SD = 0.25; outside Europe: mean = 0.50, SD = 0.24) compared to no migration background (Netherlands: mean = 0.38, SD = 0.23; both p < .01). Prenatal stress, especially perceived discrimination and maternal psychopathology, accounted for up to half of the total effect of maternal migration, which remained after adjusting for sociodemographic factors (Bindirect = 0.035, 95% CI = 0.027, 0.043, Btotal = 0.074).

CONCLUSION

Stress during pregnancy mediated the association between maternal migration status and child autistic traits. Future research should focus on early interventions to assess whether reducing prenatal stress exposure among women with a migration background can result in lower offspring autistic traits.

DIVERSITY & INCLUSION STATEMENT

We worked to ensure that the study questionnaires were prepared in an inclusive way. We worked to ensure sex and gender balance in the recruitment of human participants. We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. We actively worked to promote sex and gender balance in our author group. The author list of this paper includes contributors from the location and/or community where the research was conducted who participated in the data collection, design, analysis, and/or interpretation of the work.

Predicting autism spectrum disorder using maternal risk factors: A multi-center machine learning study

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a complex environmental etiology involving maternal risk factors, which have been combined with machine learning to predict ASD. However, limited studies have considered the factors throughout preconception, perinatal, and postnatal periods, and even fewer have been conducted in multi-center. In this study, five predictive models were developed using 57 maternal risk factors from a cohort across ten cities (ASD:1232, typically developing[TD]: 1090). The extreme gradient boosting model performed best, achieving an accuracy of 66.2 % on the external cohort from three cities (ASD:266, TD:353). The most important risk factors were identified as unstable emotions and lack of multivitamin supplementation using Shapley values. ASD risk scores were calculated based on predicted probabilities from the optimal model and divided into low, medium, and high-risk groups. The logistic analysis indicated that the high-risk group had a significantly increased risk of ASD compared to the low-risk group. Our study demonstrated the potential of machine learning models in predicting the risk for ASD based on maternal factors. The developed model provided insights into the maternal emotion and nutrition factors associated with ASD and highlighted the potential clinical applicability of the developed model in identifying high-risk populations.

Understanding the course of attention deficit hyperactivity disorder in children born after a threatened preterm labor: a 6-year cohort study

BACKGROUND

Recent research suggests that children born after suspected preterm labor may observe a potential cluster with different attention deficit hyperactivity disorder features, depending on the time of birth. However, the evolution of symptoms and their predictors remain unknown in this population.

OBJECTIVE

This study aimed to examine the trajectories of attention deficit hyperactivity disorder symptoms of children born after suspected preterm labor, between ages 2 and 6 years, considering prematurity condition and comparing with controls. In addition, this study aimed to find potential modifiable predictors of evolution to enhance prognosis.

STUDY DESIGN

In this prospective cohort study, 119 mother-child pairs who experienced suspected preterm labor and 60 controls were included. Patients were divided according to prematurity condition in full term (n=27), late preterm (n=55), and very preterm (n=37). Attention deficit hyperactivity disorder symptoms were assessed at ages 2 and 6 years. The association between potential modifying factors (group, time of assessment, sex, birthweight percentile, maternal history of trauma, maternal anxiety at diagnosis, and maternal anxiety during the children's assessments) and disorder trajectories was assessed by adjusting the Bayesian mixed linear models. All analyses were performed in R (version 4.3.0; R Foundation for Statistical Computing, Vienna, Austria).

RESULTS

An interaction emerged between time and group, with late-preterm neonates born after suspected preterm labor being the only group to improve from ages 2 to 6 years (-2.26 points in Conners scale per percentile decrease and 0.98 probability of effect). Another interaction between time and maternal anxiety at postnatal time assessments intensified over time (0.07 and 0.84). Predictors of symptom severity included lower weight percentile at birth (-0.2 and 0.96), male sex (-2.99 and <0.99), higher maternal anxiety at diagnosis (+0.08 and 0.99), and maternal history of trauma (+0.23 and 0.98).

CONCLUSION

Unlike very-preterm and full-term children, those born late preterm showed an improvement over time, probably because late-preterm children do not carry the sequelae derived from severe prematurity but benefit from close monitoring. As maternal psychopathology emerged as a determinant modifier of course and severity, it is crucial to develop targeted psychological interventions for pregnant individuals and reevaluate monitoring programs for their offspring, regardless of prematurity.

Pre- and Perinatal Risk Factors for Youth with Autism Spectrum Disorder Versus Youth with Other Mental Health Disorders

Research has linked pre- and perinatal complications (PPCs) with increased risk for autism spectrum disorder (ASD). However, PPCs are also known risk factors for other mental health disorders. This study explored which PPCs are specific risk factors for ASD, as opposed to other forms of psychopathology, among a large sample of clinically-referred youth. Archival data were used from 1177 youth who were evaluated at a hospital-based autism clinic. Results from logistic regressions indicated that use of tobacco, alcohol, or drugs, or experiencing amniocentesis predicted inclusion in the non-ASD group, while physical difficulties with delivery predicted inclusion in the ASD group. Possible explanations and implications for these findings are discussed.

The Association between Threatened Miscarriage and Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder in Offspring by Age 14 Years

OBJECTIVE

To examine the association between threatened miscarriage, and neurodevelopmental disorders, including autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in offspring by age 14 years.

METHODS

We used data from the Millennium Cohort Study, a nationally representative longitudinal study of children born in the UK. Data on threatened miscarriage and potential confounders were maternal-reported and collected at 9 months postpartum. Data on ASD and ADHD were based on maternal-reported doctor diagnoses and collected when children were aged 5, 7, 11 and 14 years. A diagnosis of ASD or ADHD was assumed if parents reported ASD or ADHD at age 5, 7, 11 or 14 years. Crude and adjusted logistic regression examined threatened miscarriage and ASD and ADHD relationship, adjusting for several sociodemographic, maternal and lifestyle factors.

RESULTS

A total of 18,294 singleton babies were included at baseline, and 1,104 (6.0%) women experienced a threatened miscarriage during their pregnancy. Adjusted results suggested an association between threatened miscarriage and ASD (OR: 1.55, 95% CI 1.15, 2.08), and ADHD (OR: 1.51, 95% CI 1.09, 2.10) by age 14 years. E-values for threatened miscarriage and ASD were 2.47, while the lower limits of the 95% CI were 1.57. E-values for threatened miscarriage and ADHD were 2.39, while the corresponding lower limits of the 95% CI were 1.40.

CONCLUSION

Threatened miscarriage was associated with an increased likelihood of ASD and ADHD by the age of 14 years, however, residual confounding cannot be ruled out. Placental pathology may be a potential mechanism for the observed associations.

Decreased amygdala-sensorimotor connectivity mediates the association between prenatal stress and broad autism phenotype in young adults: Project Ice Storm

Studies show that prenatal maternal stress (PNMS) is related to risk for child autism, and to atypical amygdala functional connectivity in the autistic child. Yet, it remains unclear whether amygdala functional connectivity mediates the association between PNMS and autistic traits, particularly in young adult offspring. We recruited women who were pregnant during, or within 3 months of, the 1998 Quebec ice storm crisis, and assessed three aspects of PNMS: objective hardship (events experienced during the ice storm), subjective distress (post-traumatic stress symptoms experienced as a result of the ice storm) and cognitive appraisal. At age 19, 32 young adults (21 females) self-reported their autistic-like traits (i.e., aloof personality, pragmatic language impairment and rigid personality), and underwent structural MRI and resting-state functional MRI scans. Seed-to-voxel analyses were conducted to map the amygdala functional connectivity network. Mediation analyses were implemented with bootstrapping of 20,000 resamplings. We found that greater maternal objective hardship was associated with weaker functional connectivity between the left amygdala and the right postcentral gyrus, which was then associated with more pragmatic language impairment. Greater maternal subjective distress was associated with weaker functional connectivity between the right amygdala and the left precentral gyrus, which was then associated with more aloof personality. Our results demonstrate that the long-lasting effect of PNMS on offspring autistic-like traits may be mediated by decreased amygdala-sensorimotor circuits. The differences between amygdala-sensory and amygdala-motor pathways mediating different aspects of PNMS on different autism phenotypes need to be studied further.

Developmental Neuroendocrinology of Early-Life Stress: Impact on Child Development and Behavior

Our internal balance, or homeostasis, is threatened or perceived as threatened by stressful stimuli, the stressors. The stress system is a highly conserved system that adjusts homeostasis to the resting state. Through the concurrent activation of the hypothalamic-pituitary-adrenal axis and the locus coeruleus/norepinephrine-autonomic nervous systems, the stress system provides the appropriate physical and behavioral responses, collectively termed as "stress response", to restore homeostasis. If the stress response is prolonged, excessive or even inadequate, several acute or chronic stress-related pathologic conditions may develop in childhood, adolescence and adult life. On the other hand, earlylife exposure to stressors has been recognized as a major contributing factor underlying the pathogenesis of non-communicable disorders, including neurodevelopmental disorders. Accumulating evidence suggests that early-life stress has been associated with an increased risk for attention deficit hyperactivity disorder and autism spectrum disorder in the offspring, although findings are still controversial. Nevertheless, at the molecular level, early-life stressors alter the chemical structure of cytosines located in the regulatory regions of genes, mostly through the addition of methyl groups. These epigenetic modifications result in the suppression of gene expression without changing the DNA sequence. In addition to DNA methylation, several lines of evidence support the role of non-coding RNAs in the evolving field of epigenetics. In this review article, we present the anatomical and functional components of the stress system, discuss the proper, in terms of quality and quantity, stress response, and provide an update on the impact of early-life stress on child development and behavior.

Environmental Influences on Individuals with Autistic Spectrum Disorders with Special Emphasis on Seasonality: An Overview

This paper offers an in-depth exploration of the intricate relationship between environmental factors and autism spectrum disorder (ASD), with a special emphasis on seasonality. It reviews existing research, providing a comprehensive summary of findings and highlighting the multifaceted dimensions of several environmental factors influencing the etiology of ASD. The discussion encompasses various elements, including birth months, maternal health, dietary choices, and vitamin D deficiency, delving into the intricate interplay of seasonality with environmental influences such as viral infections and solar radiation. The present study raises essential questions regarding the timing of environmental influences and the factors contributing to the rising prevalence of ASD. Ultimately, it underscores the need for future epidemiological research to incorporate more extensive investigations of environmental risk factors and employ advanced statistical analyses. This comprehensive overview contributes to a deeper understanding of how environmental factors, particularly seasonality, may be linked to the occurrence of ASD and its increasing prevalence, recognizing the multifaceted and diverse nature of these interactions.

Infant feeding practices and autism spectrum disorder in US children aged 2-5 years: the national survey of children's health (NSCH) 2016-2020

OBJECTIVE

To investigate the relationship between infant feeding practices and autism spectrum disorder (ASD) among children aged 2-5 years in the United States (US).

METHODS

Data from the 2016-2020 National Survey of Children's Health, a nationally representative cross-sectional survey, were utilized for this study. Questionnaires were administered to parents of children aged 2-5 years to gather information on ASD diagnosis, infant feeding practices, and demographic factors (e.g., child sex, ethnic group, and maternal age at birth). Logistic regression with sample weights was employed to assess the association between infant feeding practices and ASD, while controlling for demographic variables. Polynomial regression models were used to examine trends in exclusive breastfeeding and ever breastfeeding rates among children with and without ASD.

RESULTS

A total of 35,050 children aged 2-5 years were analyzed, including 616 diagnosed with ASD, after excluding participants with missing information on breastfeeding and ASD diagnosis. Of these children with ASD, 76.6% (n = 472) had a breastfeeding history, with 67.5% (n = 416) engaged in partial breastfeeding and 9.1% (n = 56) exclusively breastfed. Adjusted odds ratios for each additional month of breastfeeding compared to never being breastfed were 0.98 (95% CI, 0.96-1.01). The adjusted odds ratios for breastfeeding durations of > 0-6 months, > 6-12 months, > 12-24 months, and > 24 months were 0.81 (95% CI, 0.50-1.31), 0.65 (95% CI, 0.36-1.18), 0.81 (95% CI, 0.44-1.49), and 0.48 (95% CI, 0.23-1.01), respectively. Compared to children who were never breastfed, the adjusted odds ratio for children who were ever breastfed was 0.74 (95% CI, 0.47-1.18). Among children with ASD, the proportion of ever breastfeeding declined from 82.0% in 2017 to 64.3% in 2020, while exclusive breastfeeding decreased from 12.0% in 2016 to 4.2% in 2020.

CONCLUSIONS AND RELEVANCE

Although no significant association was found between infant feeding practices and ASD among US children aged 2-5 years, the rates of breastfeeding, particularly exclusive breastfeeding, were suboptimal among children with ASD. This highlights the need for specific policies and practices to promote and support breastfeeding among parents of children with ASD or those at high risk of having a child with ASD.

Preconception and prenatal maternal stress are associated with broad autism phenotype in young adults: Project Ice Storm

Studies show associations between prenatal maternal stress (PNMS) and child autism, with little attention paid to PNMS and autism in young adulthood. The broad autism phenotype (BAP), encompassing sub-clinical levels of autism, includes aloof personality, pragmatic language impairment and rigid personality. It remains unclear whether different aspects of PNMS explain variance in different BAP domains in young adult offspring. We recruited women who were pregnant during, or within 3 months of, the 1998 Quebec ice storm crisis, and assessed three aspects of their stress (i.e., objective hardship, subjective distress and cognitive appraisal). At age 19, the young adult offspring (n = 33, 22F / 11M) completed a BAP self-report. Linear and logistic regressions were implemented to examine associations between PNMS and BAP traits. Up to 21.4% of the variance in BAP total score and in BAP three domains tended to be explained by at least one aspect of maternal stress, For example, 16.8% of the variance in aloof personality tended to be explained by maternal objective hardship; 15.1% of the variance in pragmatic language impairment tended to be explained by maternal subjective distress; 20.0% of the variance in rigid personality tended to be explained by maternal objective hardship and 14.3% by maternal cognitive appraisal. Given the small sample size, the results should be interpreted with caution. In conclusion, this small prospective study suggests that different aspects of maternal stress could have differential effects on different components of BAP traits in young adults.

Early Life Stress, Hormones, and Neurodevelopmental Disorders

BACKGROUND

Early life stress (ELS) describes a broad spectrum of adverse and stressful prenatal events, namely, prenatal maternal stress (PMS), or early postnatal events, which can have detrimental long-term influences on the physiology, cognition, and behavior of an individual. There is abundant evidence indicating that ELS exerts its lasting effects on the physical and mental health of the individual, likely acting through a number of mediating mechanisms, including the disruption of developmental programming of the fetus. Neurodevelopmental disorders (NDDs), for example, attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), are a group of conditions that typically manifest during infancy, childhood, or adolescence and are characterized by developmental deficits in various domains.

SUMMARY

The scope of the current mini-review is to provide an up-to-date summary of the findings regarding the association of ELS and NDDs and the possible hormonal mechanisms through which PMS exerts its impact on neurodevelopment. We focus on the available evidence regarding children and adolescents diagnosed with ADHD or ASD. ELS exposure during developmental vulnerability windows may increase the risk for either subclinical neuropsychological alterations or clinical conditions, such as NDDs. In fact, a large body of evidence underlies the association of ELS exposure and increased risk for NDDs in the offspring.

KEY MESSAGES

The majority of data suggest that ELS, including PMS, may be associated with ADHD and ASD in the offspring, although there is no consensus regarding the critical developmental periods. Carefully controlled prospective studies are needed to determine the possible causal processes and mechanisms underlying the association of ELS and NDDs.

The Association between Threatened Abortion and the Risk of Autism Spectrum Disorders among Children: A Meta-Analysis

Background

The current study is aimed at updating the observational studies on the relationship between threatened abortion and the risk of ASD.

Methods

The search keywords were covered in three electronic databases PubMed, Web of Science, and Scopus up to April 2022. The modified Newcastle-Ottawa scale (NOS) was applied to detect the quality of epidemiological studies. We used the chi-square test and the I ² statistic to show the heterogeneity among articles. I ² more than 50% was considered high heterogeneity. Egger's and Begg's line regression tests were used for evaluating the publication bias. The random-effects model was applied for the analysis of the findings. The Stata 13.0 software package was applied for analysis and indicated p value less than 0.05 as a significant level.

Results

The pooled analysis reported significant differences between threatened abortion and the risk of ASD in adjusted studies (OR = 1.93; 95% CI: 1.12, 2.73; I ² = 59.5.0%) and in crude studies (OR = 2.17; 95% CI: 1.46, 2.88; I ² = 39.5%). The evidence of publication bias was not found.

Conclusions

The findings suggest that threatened abortion is a risk factor for ASD. As a result, screening tools to detect are necessary in mothers facing a threatened abortion.

Not breastfeeding and risk of autism spectrum disorders among children: a meta-analysis

BACKGROUND

To our knowledge, this is the first meta-analysis of the association of not breastfeeding and the risk of autism spectrum disorder (ASD) based on observational studies.

PURPOSE

This meta-analysis aimed to evaluate of the association of not breastfeeding and the risk of ASD.

METHODS

Three databases (PubMed, Web of Science, and Scopus) were systematically searched until December 2021. Heterogeneity was determined using the chi-square test and its quantity was measured using the I2 statistic. The Begg line regression test was used to assess publication bias. A random-effects model was used to analyze the data. Seven studies were included in this meta-analysis.

RESULTS

The total study population included 3,270 individuals. According to the random-effects model, the estimated odds ratio of the risk of ASD associated with not breastfeeding was 1.81 (95% confidence interval, 1.35-2.27; I2=0%).

CONCLUSION

The results of the included studies were homogeneous. Our findings showed that not breastfeeding is a risk factor for ASD. These results suggest the importance of breastfeeding in decreasing the risk of ASD in children.

Attention-deficit/hyperactivity disorder and other neurodevelopmental disorders in offspring of parents with depression and bipolar disorder

BACKGROUND

Offspring of parents with major mood disorders (MDDs) are at increased risk for early psychopathology. We aim to compare the rates of neurodevelopmental disorders in offspring of parents with bipolar disorder, major depressive disorder, and controls.

METHOD

We established a lifetime diagnosis of neurodevelopmental disorders [attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, communication disorders, intellectual disabilities, specific learning disorders, and motor disorders] using the Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime Version in 400 participants (mean age 11.3 + s.d. 3.9 years), including 93 offspring of parents with bipolar disorder, 182 offspring of parents with major depressive disorder, and 125 control offspring of parents with no mood disorder.

RESULTS

Neurodevelopmental disorders were elevated in offspring of parents with bipolar disorder [odds ratio (OR) 2.34, 95% confidence interval (CI) 1.23-4.47, p = 0.010] and major depressive disorder (OR 1.87, 95% CI 1.03-3.39, p = 0.035) compared to controls. This difference was driven by the rates of ADHD, which were highest among offspring of parents with bipolar disorder (30.1%), intermediate in offspring of parents with major depressive disorder (24.2%), and lowest in controls (14.4%). There were no significant differences in frequencies of other neurodevelopmental disorders between the three groups. Chronic course of mood disorder in parents was associated with higher rates of any neurodevelopmental disorder and higher rates of ADHD in offspring.

CONCLUSIONS

Our findings suggest monitoring for ADHD and other neurodevelopmental disorders in offspring of parents with MDDs may be indicated to improve early diagnosis and treatment.

Postpartum depression and ADHD in the offspring: Systematic review and meta-analysis

BACKGROUND

Postpartum depression (PPD) is a disorder that has a severe impact on a woman's mental state and mood after birth. Research has shown that postnatal levels of family adversity and maternal psychopathology are associated with Attention Deficit Hyperactivity Disorder (ADHD). This paper is intended to examine the association among maternal PPD and the risk of ADHD in the offspring.

METHODS

Keyword search was conducted for PsycINFO, PubMed, Google Scholar, and Embase up to Feb 28, 2021; studies in English were deemed eligible. Random-effects meta-analysis and meta-regression analysis took place. Subgroup analyses by study design, geographical region, level of adjustment and study setting were performed.

RESULTS

Nine cohort studies and two case-control studies published from 2003 to 2019 were included in the qualitative synthesis; among them, eight studies were synthesized in the meta-analysis. Overall, maternal PPD was associated with an increased risk of ADHD in the offspring (pooled relative risk, RR = 1.69, 95%CI: 1.27-2.26). Significant associations were noted in the subsets of cohort studies, studies implementing multivariate analyses and registry-based surveys.

LIMITATIONS

Overall, a larger number of studies of the field are needed. Data collection relied on self-report and attrition bias limited the validity of eligible studies. Studies from developing countries were underrepresented. There was significant publication bias (p = 0.035, Egger's test).

CONCLUSIONS

The relationship between PPD and ADHD in children was found to be significant in this systematic review and meta-analysis and reveals the need for further investigation in various geographical regions.

Maternal Distress during Pregnancy and the Postpartum Period: Underlying Mechanisms and Child's Developmental Outcomes-A Narrative Review

Maternal mental health may be considered a determining factor influencing fetal and child development. An essential factor with potentially negative consequences for a child's psychophysiological development is the presence of maternal distress during pregnancy and the postpartum period. The review is organized and presented to explore and describe the effects of anxiety, stress, and depression in pregnancy and the postpartum period on adverse child developmental outcomes. The neurobiology of maternal distress and the transmission mechanisms at the molecular level to the fetus and child are noted. In addition, the paper discusses the findings of longitudinal studies in which early child development is monitored concerning the presence of maternal distress in pregnancy and the postpartum period. This topic gained importance in the COVID-19 pandemic context, during which a higher frequency of maternal psychological disorders was observed. The need for further interdisciplinary research on the relationship between maternal mental health and fetal/child development was highlighted, especially on the biological mechanisms underlying the transmission of maternal distress to the (unborn) child, to achieve positive developmental outcomes and improve maternal and child well-being.

[Early prognostic of ASD: A challenge]

Autism Spectrum Disorders (ASD) are born in the womb generated by intrauterine genetic or environmental insult. ASD diagnostic is made at the age of 3-5 years in Europe and in the US. Relying on this, we have tested the hypothesis of identifying already at birth babies who might be diagnosed later with ASD, thereby facilitating an early use of psychoeducative techniques to attenuate the severity of the symptoms. Here, we discuss the various approaches that have been used to enable an early diagnosis. We have ourselves used an approach based on a "without a priori" machine learning analysis of all maternity biological and ultrasound data available in French maternities (around 116) in utero and after birth. This program made it possible to identify at birth almost all (96%) of babies who will be later neurotypical and around half of those who will be diagnosed with ASD. Some of the parameters allowing this identification were largely unexpected with no known links with ASD. This approach will enable an early identification of babies at risk, but also might be used to diagnose ASD later on, and perhaps could help to get a better understanding of the heterogeneity of ASD.

Association of Breastfeeding for the First Six Months of Life and Autism Spectrum Disorders: A National Multi-Center Study in China

Previous studies have shown that exclusive breastfeeding is associated with lower odds of having autism spectrum disorders (ASD) in children, but data are lacking in Asian countries, especially China. This cross-sectional study of seven cities in China collected data from August 2016 to March 2017 from 6049 toddlers aged 16-30 months and their parents who responded to questionnaires. The breastfeeding status was collected via questionnaires based on recommendations from the World Health Organization. The standard procedure for screening and diagnosis was applied to identify toddlers with ASD. Among the 6049 toddlers (3364 boys [55.6%]; mean [SD] age, 22.7 [4.1] months), 71 toddlers (1.2%) were identified as ASD. The prevalence of exclusive breastfeeding, partial breastfeeding, and not breastfeeding was 48.8%, 42.2%, and 9.1%, respectively. Compared to toddlers with exclusive breastfeeding, toddlers with partial breastfeeding or without breastfeeding had higher odds of having ASD (odd ratios [OR]: 1.55, 95% confidence interval [CI]: 0.90-2.74; OR: 2.34, 95% CI: 1.10-4.82). We did not find significant modification of demographic characteristics on the associations. The results remained robust in multiple sensitivity analyses. Toddlers without breastfeeding for the first six months of life had higher odds of having ASD, and our findings shed light on the necessity of strengthening public health efforts to increase exclusive breastfeeding in China.

Risk factors associated with stress symptoms during pregnancy and postpartum: integrative literature review

Stressful events during prenatal and postpartum have been associated with an increase in the susceptibility to the onset of various diseases, threatening mental and physical health of mother and baby. The aim of this study was to synthesize and analyze the literature related to risk factors associated with stress symptoms during pregnancy and immediate postpartum by means of an integrative review. The search was conducted from January 2013 to July 2020, consulting the following databases: PubMed, PsycINFO, CINAHL, Web of Science and LILACS. In total, 1,677 studies were identified, resulting in 38 articles included in this review. The risk factors most associated with stress in pregnancy and postpartum were related to emotional factors (including mental health, traumatic events and obstetric complications); social and economic factors; mother's health conditions and life style behaviors, and social support and partner related stress. The results are discussed under the light of the biopsychosocial model, which proposes that biological, psychological, and social domains should be considered in order to minimize psychosocial risk conditions. It is concluded that strategies to promote psychological care, education, additional social support and health behaviors should be considered to prevent adverse birth outcomes and to increase maternal well-being.

Association between prenatal and perinatal factors and the severity of clinical presentation of children with ASD: Report from the ELENA COHORT

Many studies have suggested that prenatal and perinatal factors increase the risk for autism spectrum disorder (ASD). However, few reports have addressed the question of their influence on the severity of the clinical presentation of children with ASD. Our objective was to determine the prenatal and perinatal factors that are associated with the severity of autistic symptoms and intellectual and adaptive functioning deficits. Data were collected from a subset of 169 children with a confirmed diagnosis of ASD, recruited from the ELENA cohort. A risk of premature delivery was associated, with an increased risk for severe autistic symptoms and placental pathologies and birth complications were associated with an increased risk of communication adaptive deficits, in multivariate analysis. Our results highlight the importance of systematic screening for these pre/perinatal factors, especially in mothers at risk of having a child with ASD.

SARS-CoV-2 Infection in Pregnant Women: Neuroimmune-Endocrine Changes at the Maternal-Fetal Interface

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has devastating effects on the population worldwide. Given this scenario, the extent of the impact of the disease on more vulnerable individuals, such as pregnant women, is of great concern. Although pregnancy may be a risk factor in respiratory virus infections, there are no considerable differences regarding COVID-19 severity observed between pregnant and nonpregnant women. In these circumstances, an emergent concern is the possibility of neurodevelopmental and neuropsychiatric harm for the offspring of infected mothers. Currently, there is no stronger evidence indicating vertical transmission of SARS-CoV-2; however, the exacerbated inflammatory response observed in the disease could lead to several impairments in the offspring's brain. Furthermore, in the face of historical knowledge on possible long-term consequences for the progeny's brain after infection by viruses, we must consider that this might be another deleterious facet of COVID-19. In light of neuroimmune interactions at the maternal-fetal interface, we review here the possible harmful outcomes to the offspring brains of mothers infected by SARS-CoV-2.

The association between gestational diabetes and ASD and ADHD: a systematic review and meta-analysis

There is growing evidence for a role of maternal diabetes in the pathogenesis of neurodevelopmental disorders. However, the specific association between gestational diabetes (GDM), as opposed to pre-gestational diabetes, has been poorly isolated. Thus the aim was to systematically review and meta-analyse literature pertaining to prevalence and risk for two neurodevelopmental disorders: autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), when exposed to GDM. PubMed, Cochrane Library, EMBASE, PsycINFO and CINAHL were systematically searched for eligible literature, with forward and backward citation tracking. Screening for eligibility, risk of bias assessment and data extraction were performed by two independent reviewers. 18 studies measuring ASD and 15 measuring ADHD met inclusion criteria. On meta-analysis there was an increased risk of ASD (OR 1.42; 95% CI 1.22, 1.65) but not ADHD (OR 1.01; 95% CI 0.79, 1.28). We discuss potential mechanisms for these differing risks. Greater understanding of risk factors, including GDM, for these neurodevelopmental disorders and potential mechanisms may help inform strategies aimed at prevention of exposure to these adversities during pregnancy.

Perinatal Factors Associated with Autism Spectrum Disorder in Jamaican Children

Mode of delivery, preterm birth, and low birth weight (LBW) are hypothesized to be associated with autism spectrum disorder (ASD) in the offspring. Using data from 343 ASD cases (2-8 years) and their age- and sex-matched typically developing controls in Jamaica we investigated these hypotheses. Our statistical analyses revealed that the parish of residence could modify the association between cesarean delivery and ASD, with a difference found in this relationship in Kingston parish [matched odds ratio (MOR) (95% confidence interval (CI)) 2.30 (1.17-4.53)] and other parishes [MOR (95% CI) 0.87 (0.48-1.59)]. Although the associations of LBW and preterm birth with ASD were not significant, we observed a significant interaction between LBW and the household socioeconomic status. These findings require replication.

Association of parental depression with offspring attention deficit hyperactivity disorder and autism spectrum disorder: A nationwide birth cohort study

BACKGROUND

Studies have indicated that parental depression was slightly related to the increased risk of offspring attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). However, the association between exposure to parental depression at different neurodevelopmental stages (i.e., perinatal or postnatal period) and subsequent ADHD and ASD development remained uncertain.

METHOD

708,515 children born between 2001 and 2008 were screened for ADHD and ASD based on ICD-9-CM codes of 314 and 299 given by psychiatrists from their birth to the end of 2011. Paternal and maternal depression was separately assessed during five periods, namely those before pregnancy (pre-pregnancy), during pregnancy (perinatal), and <1, 1-3, and >3 years after childbirth (postnatal). Cox regression analyses were performed.

RESULTS

Both paternal and maternal depression occurring in the pre-pregnancy, perinatal and postnatal periods were significantly associated with subsequent ADHD and ASD in the offspring, with hazard ratios between 1.42 (95% confidence interval [CI]: 1.35-1.49) and 2.25 (2.09-2.41). The chronicity and additive effect of paternal and maternal depression were related to increased risks of offspring ADHD and ASD. The effects of maternal depression were stronger than the effects of paternal depression for offspring ADHD (HR: 1.35, 95% CI: 1.27-1.45) and ASD (HR: 1.23, 95% CI: 1.05-1.46) risks.

CONCLUSION

Both paternal depression and maternal depression in the pre-pregnancy, perinatal and postnatal periods increases offspring ADHD and ASD risks, and these risks increase further with increases in the duration of parental depression and with the additive effect of parental and maternal depression.

Climate change is a major stressor causing poor pregnancy outcomes and child development

The climate crisis is the existential threat of our times and for generations to come. This is no longer a threat but a reality affecting us, our children, and the generations that follow. Pregnant mothers, their fetuses, and their children are among those at greatest risk in every population and every jurisdiction. A timely consideration is the health of racialized groups who are particularly vulnerable owing to the confluence of several risk factors that are compounded by climate change. Included among these are Indigenous communities that are the most directly threatened by climate change. This review discusses the main health challenges faced by mothers, fathers, and their children during the climate crisis, focusing on mental health as a causal factor. Exploration of this topic includes the role of prenatal maternal and paternal stresses, allostatic load, and the effect of degradation of the environment and ecosystems on individuals. These will be examined in relation to adverse pregnancy outcomes and altered developmental trajectories of children. The climate crisis is a health threat multiplier that amplifies the health inequities of the most at-risk populations and individuals. It accelerates the increase in allostatic load of those at risk. The path of tragedy begins with an accumulating allostatic load that overwhelms both individual and socio-ecological resilience. This can lead to worse mental health including depression and anxiety and, in the case of pregnant women and their children, more adverse pregnancy outcomes and impaired developmental trajectories for their newborn children. We argue that there is an urgent need to develop new (or re-discover or re-purpose existing) tools that will predict communities and individuals who are experiencing the highest levels of climate-related hazards and intervene to reduce stress and increase resilience in pre-conceptual women and men, pregnant and post-partum women, and their young children.

The GABA Developmental Shift Is Abolished by Maternal Immune Activation Already at Birth

Epidemiological and experimental studies suggest that maternal immune activation (MIA) leads to developmental brain disorders, but whether the pathogenic mechanism impacts neurons already at birth is not known. We now report that MIA abolishes in mice the oxytocin-mediated delivery γ-aminobutyric acid (GABA) shift from depolarizing to hyperpolarizing in CA3 pyramidal neurons, and this is restored by the NKCC1 chloride importer antagonist bumetanide. Furthermore, MIA hippocampal pyramidal neurons at birth have a more exuberant apical arbor organization and increased apical dendritic length than age-matched controls. The frequency of spontaneous glutamatergic postsynaptic currents is also increased in MIA offspring, as well as the pairwise correlation of the synchronized firing of active cells in CA3. These alterations produced by MIA persist, since at P14-15 GABA action remains depolarizing, produces excitatory action, and network activity remains elevated with a higher frequency of spontaneous glutamatergic postsynaptic currents. Therefore, the pathogenic actions of MIA lead to important morphophysiological and network alterations in the hippocampus already at birth.

Eating and Mealtime Behaviors in Patients with Autism Spectrum Disorder: Current Perspectives

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social and communication skills and repetitive and restrictive behaviors. Children and adolescents with ASD are more likely to present feeding problems than their typically developing peers are. The present narrative review of literature aims to highlight the most recent evidence about epidemiology and presentations of eating and mealtime behavioral abnormalities in ASD from infancy to adolescence. Abnormalities in breastfeeding and acceptance of complementary foods have been described by most of the studies evaluating ASD early feeding history. Among the various eating and mealtime behaviors identified in ASD children and adolescents, the most common was food selectivity. The present review also provides brief overviews of the various aspects of food that may influence food acceptance by ASD patients and of the correlation between eating problems and ASD core symptoms, as well as with cognitive level, language skills, and family environment. However, studies evaluating eating problems in ASD children and adolescents are very heterogeneous and they show methodological differences. Moreover, the absence of unique definitions of eating and mealtime behaviors in ASD further limits the comparability of studies.

Maternal stress in the first 1000 days and risk of childhood obesity: a systematic review

Objective: Maternal stress is associated with adverse child outcomes. Conception to 2-years postpartum (the first 1000 days) is a developmentally sensitive period for stress exposure. The role of maternal stress in the first 1000 days on child obesity risk is unclear. This review systematically examines the relationship between maternal stress across the first 1000 days and child obesity risk. Methods: The Cochrane Library, MEDLINE, PsycINFO, EMBASE, CINAHL, and Maternity and Infant Care were searched from inception to June 2018. Eligible studies included women who experienced maternal stress in the first 1000 days; an included a measure of maternal stress and of child anthropometrics. Results: Sixteen studies met inclusion criteria, the majority of these examined prenatal stress exposure. Inconsistent effects were observed for psychological and physiological stress responses, on child weight outcomes. Environmental stress exposures, including natural disaster and bereavement, were more consistently associated with increased obesity risk. Conclusion: This review does not provide support for the effects of psychological or physiological maternal stress on child weight outcomes; there is some evidence of associations between environmental stress exposures and greater childhood adiposity. Variation in conceptualisation and measurement of stress, timing of stress exposure, and limited examination of stress-related behaviours were noted.

Association of breastfeeding status with risk of autism spectrum disorder: A systematic review, dose-response analysis and meta-analysis

Current evidence indicates that nutritional status in newborns, especially the duration of breastfeeding, plays a key role in the pathogenesis of autism spectrum disorder. We aimed to systematically review and meta-analyze relevant studies with findings of an association between autism spectrum disorder and breastfeeding patterns, and undertook an extensive dose-response analysis to interpret the results more accurately. Ten electronic databases and manual search of reference lists were used to identify relevant studies in September 2018. Dose-response and conventional meta-analysis were conducted by the random-effects model. The study protocol was registered in PROSPERO with CRD42016043128. Seven case-control studies were found in which the association between ever breastfeeding and risk of autism spectrum disorder was investigated. We found a 58 % decrease in the risk of autism spectrum disorder with ever breastfeeding and a 76 % decrease in the risk with exclusive breastfeeding. According to our dose-response meta-analysis, breastfeeding for 6 months was associated with a 54 % reduction in the risk. In the conventional meta-analysis, breastfeeding for 12-24 months was associated with the most significant reduction in the risk of autism spectrum disorder. Our results highlight the importance of breastfeeding to decrease the risk of autism spectrum disorder.

Cumulative evidence for association of parental diabetes mellitus and attention-deficit/hyperactivity disorder

We conducted a systematic review and meta-analysis to evaluate the association between parental diabetes mellitus and the risk of ADHD in offspring. The PubMed, EMBASE, Cochrane, and Web of Science databases were searched from inception to May 31, 2019. Thirteen observational studies containing 5,052,736 participants were included. Two reviewers independently extracted data and assessed the quality of the studies using predefined standard procedures. Random-effects model were used. We found that maternal pregestational diabetes mellitus (PGDM) was associated with an increased risk of ADHD in offspring (odds ratio [OR]: 1.40; 95% confidence interval [CI]:1.31-1.50) in adjusted analyses. Increased risks of ADHD in offspring were also observed among those with maternal preexisting type 1 diabetes (T1D) (OR: 1.39; 95% CI: 1.27-1.52) and paternal T1D (OR: 1.20; 95% CI: 1.13-1.28) in adjusted analyses. Sensitivity analyses supported the robustness of our findings. Future studies should use robust designs to address whether the association with parental diabetes mellitus is causal.

Prenatal maternal stress and risk of neurodevelopmental disorders in the offspring: a systematic review and meta-analysis

PURPOSE

Exposure to prenatal stress has been reported to affect the risk of adverse neurodevelopmental outcomes in the offspring; however, there is currently no clear consensus. The aim of this systematic review and meta-analysis was to examine the existing literature on the association between prenatal stress and autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) in the offspring.

METHODS

Based on a registered protocol, we searched several electronic databases for articles in accordance with a detailed search strategy. We performed this study following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA).

RESULTS

Prenatal stress was significantly associated with an increased risk of both ASD (pooled OR 1.64 [95% CI 1.15-2.34]; I² = 90%; 15 articles) and ADHD (pooled OR 1.72 [95% CI 1.27-2.34]; I² = 85%; 12 articles).

CONCLUSIONS

This study suggests that prenatal stress may be associated with ASD and ADHD; however, several limitations in the reviewed literature should be noted including significant heterogeneity and there is a need for carefully controlled future studies in this area.

Multiple prenatal stresses increase sexual dimorphism in adult offspring behavior

INTRODUCTION

Maternal gestational stress and immune activation have independently been associated with affective and neurodevelopmental disorders across the lifespan. We investigated whether rats exposed to prenatal maternal stressors (PNMS) consisting of psychological stress, interleukin (IL)-1β or both (two-hit stress) during critical developmental windows displayed a behavioral phenotype representative of these conditions.

METHODS

Long-Evans dams were exposed to psychological stressors consisting of restraint stress and forced swimming from gestational day (GD)12 to 18 or to no stress (controls). From GD17 until day of delivery, these same animals were injected with saline or IL-1β as a second hit and immune stressor (5 μg/day, intraperitoneally). The behavior of F1 offspring adults was tested on the open field test, elevated plus maze and affective exploration task on postnatal days (P)90, 100 and 110 respectively.

RESULTS

The effects of PNMS differed depending on the specific testing environment and potentially the age at assessment, especially in female offspring. Both locomotion and anxiety-like behavioral measures were susceptible to PNMS effects. In females, psychological stress increased anxiety-like behavior, whereas IL-1β had an opposite effect, inducing exploration and risk-taking behavior on the open field test and the elevated plus maze. When present, interactions between both stressors limited the anxiogenic effect of psychological stress on its own. In contrast, prenatal psychological stress increased anxiety-like behavior in adult males overall. A similar anxiogenic effect of IL-1β was only found on the open field test while the Stress*IL-1β interaction appeared to limit the effect of either alone. Contrarily, the PNMS effects on anxiety-like behavior on the affective exploration task were highly similar between both sexes. Analysis of males and females together revealed an additive effect of Stress and IL-1β on the number of exits from the refuge, a measure of risk assessment and thus correlated with anxiety.

CONCLUSION

PNMS affected offspring adult behavior in a sex-dependent manner. Effects on females were more variable, whereas psychological stress mostly induced anxiety-like behavior in males. These data highlight the sexual dimorphism in vulnerability to prenatal stressors. Maternal or stress-induced programming of the stress response and neuroinflammation may play an important role in mediating stress effects on offspring adult behavior.

Are preconceptional stressful experiences crucial elements for the aetiology of autism spectrum disorder? Insights from an animal model

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders characterized by changes in social interactions, impaired language and communication, fear responses and presence of repetitive behaviours. Although the genetic bases of ASD are well documented, the recent increase in clinical cases of idiopathic ASD indicates that several environmental risk factors could play a role in ASD aetiology. Among these, maternal exposure to psychosocial stressors during pregnancy has been hypothesized to affect the risk for ASD in offspring. Here, we tested the hypothesis that preconceptional stressful experiences might also represent crucial elements in the aetiology of ASD. We previously showed that social isolation stress during adolescence results in a marked decrease in the brain and plasma concentrations of progesterone and in the quality of maternal care that these female rats later provide to their young. Here we report that male offspring of socially isolated parents showed decreased agonistic behaviour and social transmission of flavour preference, impairment in reversal learning, increased seizure susceptibility, reduced plasma oxytocin levels, and increased plasma and brain levels of BDNF, all features resembling an ASD-like phenotype. These alterations came with no change in spatial learning, aggression, anxiety and testosterone plasma levels, and were sex-dependent. Altogether, the results suggest that preconceptional stressful experiences should be considered as crucial elements for the aetiology of ASD, and indicate that male offspring of socially isolated parents may be a useful animal model to further study the neurobiological bases of ASD, avoiding the adaptations that may occur in other genetic or pharmacologic experimental models of these disorders.

Association Between Breastfeeding Initiation and Duration and Autism Spectrum Disorder in Preschool Children Enrolled in the Study to Explore Early Development

Studies report inconsistent findings on the relationship between ASD and breastfeeding. We explored associations between ASD and breastfeeding initiation (yes/no) and duration (months categorized in tertiles) in the Study to Explore Early Development, a community-based case-control study in six sites in the Unites States. We adjusted for various child and mother demographic and pregnancy factors. Breastfeeding initiation was reported in 85.7% of mothers of children with ASD and 90.6% of mothers of controls. After adjustment, we found no significant difference in breastfeeding initiation (adjusted odds-ratio [aOR]: 0.88 and 95% confidence interval (CI) 0.60-1.28). However, mothers of children with ASD were less likely to report duration of breastfeeding in the high (≥12 months) versus low tertile (<6 months) (aOR and 95% CI: 0.61 [0.45-0.84]) or the middle (6-<12 months) versus low tertile (0.72: 0.54-0.98). The association of ASD and breastfeeding duration was slightly attenuated when the presence of the broader autism phenotype (BAP) in the mother was accounted for, but still remained for the highest tertile. This association does not appear to be totally explained by maternal BAP. We were unable to distinguish whether the difference in duration was due to difficulties breastfeeding children who later develop ASD, other factors not adjusted in our study, or greater ASD risk resulting from shorter breastfeeding duration. Longitudinal studies that compare reasons why mothers stop breastfeeding between ASD and controls and establish a temporal relation between ASD and breastfeeding are needed. Future studies should also evaluate interactions between ASD risk genes and breastfeeding. Autism Research 2019, 12: 816-829. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: In this study, we compared breastfeeding practices between mothers of children with and without autism spectrum disorder (ASD). We found that the percentage of mothers who started breastfeeding was similar between the two groups, but mothers of children with ASD breastfed for a shorter amount of time compared to mothers of children without ASD. Future studies are needed to evaluate the reasons why the duration of breastfeeding was shorter for mothers of children with ASD compared to those without ASD.

Prenatal maternal stress and risk of neurodevelopmental disorders in the offspring: A systematic review and meta-analysis protocol

Background: Prenatal maternal stress (PNMS) is defined as the experience of significant levels of prenatal stress, depression or anxiety during pregnancy. PNMS has been associated with increased risk of autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) in exposed offspring. However, these findings are inconsistent and other studies found no association, meaning a clear consensus on the impact of PNMS on ASD and ADHD risk is required. The purpose of this systematic review and meta-analysis is to summarize and critically review the existing literature on the effects of PNMS on ASD and ADHD risk. Methods: Electronic databases (PubMed, PsycINFO, Web of Science, Scopus and EMBASE) will be searched for articles following a detailed search strategy. We will include cohort and case-control studies that assessed maternal exposure to psychological and/or environmental stress and had ASD or ADHD as an outcome. Two reviewers will independently screen the titles, abstracts and full articles to identify eligible studies. We will use a standardised data extraction form for extracting data and a bias classification tool for assessing study quality. This systematic review will be reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). The generic inverse variance method will be used if possible to perform meta-analyses. Ethics and dissemination: Ethical approval is not required for this study because it will not involve the conduct or inclusion of any experimental or personal data that would require informed consent.  The systematic review will be disseminated in peer-reviewed journals. PROSPERO registration number: CRD42018084222.

Prenatal exposure to environmental insults and enhanced risk of developing Schizophrenia and Autism Spectrum Disorder: focus on biological pathways and epigenetic mechanisms

When considering neurodevelopmental disorders (NDDs), Schizophrenia (SZ) and Autism Spectrum Disorder (ASD) are considered to be among the most severe in term of prevalence, morbidity and impact on the society. Similar features and overlapping symptoms have been observed at multiple levels, suggesting common pathophysiological bases. Indeed, recent genome-wide association studies (GWAS) and epidemiological data report shared vulnerability genes and environmental triggers across the two disorders. In this review, we will discuss the possible biological mechanisms, including glutamatergic and GABAergic neurotransmissions, inflammatory signals and oxidative stress related systems, which are targeted by adverse environmental exposures and that have been associated with the development of SZ and ASD. We will also discuss the emerging role of the gut microbiome as possible interplay between environment, immune system and brain development. Finally, we will describe the involvement of epigenetic mechanisms in the maintenance of long-lasting effects of adverse environments early in life. This will allow us to better understand the pathophysiology of these NDDs, and also to identify novel targets for future treatment strategies.

Prenatal maternal stress and risk of neurodevelopmental disorders in the offspring: A systematic review and meta-analysis protocol

Background: Prenatal maternal stress (PNMS) is defined as the experience of significant levels of prenatal stress, depression or anxiety during pregnancy. PNMS has been associated with increased risk of autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) in exposed offspring. However, these findings are inconsistent and other studies found no association, meaning a clear consensus on the impact of PNMS on ASD and ADHD risk is required. The purpose of this systematic review and meta-analysis is to summarize and critically review the existing literature on the effects of PNMS on ASD and ADHD risk. Methods: Electronic databases (PubMed, PsycINFO, Web of Science, Scopus and EMBASE) will be searched for articles following a detailed search strategy. We will include cohort, case-control and cross-sectional studies that assessed maternal exposure to psychological and/or environmental stress and had ASD or ADHD as an outcome. Two reviewers will independently screen the titles, abstracts and full articles to identify eligible studies. We will use a standardised data extraction form for extracting data and a bias classification tool for assessing study quality. This systematic review will be reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). The generic inverse variance method will be used if possible to perform meta-analyses. Ethics and dissemination: Ethical approval is not required for this study because it will not involve the conduct or inclusion of any experimental or personal data that would require informed consent.  The systematic review will be disseminated in peer-reviewed journals. PROSPERO registration number: CRD42018084222.

Additive effect of congenital heart disease and early developmental disorders on attention-deficit/hyperactivity disorder and autism spectrum disorder: a nationwide population-based longitudinal study

In this retrospective nationwide population-based case-control study, we investigated the impact of congenital heart disease (CHD) on the development of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), which remains unclear. Children aged <18 years that were diagnosed with CHD (n = 3552) between January 1, 1997 and December 31, 2009 were identified from the National Health Insurance Research Database in Taiwan. Non-CHD controls (n = 14,208) matched for age and sex (1:4) were selected from the same dataset. All subjects were observed until December 31, 2011 or their death. Comorbid perinatal conditions and early developmental disorders (EDD) that were diagnosed before ADHD and ASD diagnosis were also analyzed. The incidence rates of perinatal comorbidities, EDD, ADHD, and ASD were higher in the CHD group than in the control group. Multivariate Cox regression analysis revealed that the CHD group had an increased risk of developing ADHD (adjusted hazard ratio [aHR] 2.52, 95% confidence interval CI 1.96-3.25) and ASD (aHR 1.97, 95% CI 1.11-3.52) after adjusting for confounding comorbidities. EDD, but not perinatal comorbidities were also independent risk factors for ADHD and ASD after adjustment. Subgroup analysis indicated that the risk for ADHD (HR 16.59, 95% CI 12.17-22.60) and ASD (HR 80.68, 95% CI 39.96-176.12) was greatly increased in CHD subjects with EDD than in non-CHD subjects without EDD. These findings suggested that CHD at birth and EDD during early childhood were two independent risk factors for ADHD and ASD and that concurrent CHD and EDD might additively increase these risks.

Prenatal, perinatal, and postnatal factors associated with autism: A meta-analysis

BACKGROUND

The aim of this meta-analysis was to investigate the prenatal, perinatal, and postnatal risk factors for children autism.

METHODS

PubMed, Embase, Web of Science were used to search for studies that examined the prenatal, perinatal, and postnatal risk factors for children autism. A fixed-effects model or random-effects model was used to pool the overall effect estimates.

RESULTS

Data from 37,634 autistic children and 12,081,416 nonautistic children enrolled in 17 studies were collated. During the prenatal period, the factors associated with autism risk were maternal and paternal age≥35 years, mother's and father's race: White and Asian, gestational hypertension, gestational diabetes, maternal and paternal education college graduate+, threatened abortion, and antepartum hemorrhage. During perinatal period, the factors associated with autism risk were caesarian delivery, gestational age≤36 weeks, parity≥4, spontaneous labor, induced labor, no labor, breech presentation, preeclampsia, and fetal distress. During the postnatal period, the factors associated with autism risk were low birth weight, postpartum hemorrhage, male gender, and brain anomaly. Parity≥4 and female were associated with a decreased risk of autism. In addition, exposure to cigarette smoking, urinary infection, mother's and father's race: Black and Hispanic, mother's country of birth outside Europe and North America, umbilical cord around neck, premature membrane rupture, 5-minutes Apgar score<7, and respiratory infection were not associated with increased risk of autism.

CONCLUSION

The present meta-analysis confirmed the relation between some prenatal, perinatal, and postnatal factors with autism. All these factors were examined individually, thus it was still unclear that whether these factors are causal or play a secondary role in the development of autism. Further studies are needed to verify our findings, and investigate the effects of multiple factors on autism, rather than the single factor.