A Systematic Review of the Risk Factors for Autism Spectrum Disorder in Children Born Preterm

Methodological challenges and opportunities when studying the course of autism

Longitudinal research in autism has contributed a wealth of knowledge about etiological factors, development from childhood through adulthood, life course changes and needs, as well as longer-term adult outcomes for individuals on the spectrum and their family members. This research is essential to better understand the needs of individuals as they age. However, along with the as yet unrealized opportunities to understand an individual in more nuanced ways across time, there are challenges to utilizing this research design that should be considered. These include sample and measurement diversity, retention, outcome measures, analysis, and funding considerations. This article outlines some of the most pressing challenges together with potential solutions to maximize the value of longitudinal research designs that can help address questions that are of high priority to the autism community.Lay AbstractLongitudinal research has been critical to understand the life course of people with autism, including factors which increase the probability of an autism diagnosis, the emergence of early markers, co-occurring psychiatric conditions, predication of future educational and support needs across childhood and adulthood, and understanding what makes each person unique and contributes to the well-being of autistic people and their families. However, these studies take time, patience, investment of families and individuals, scientists and are challenging to all involved. This article will outline some of the issues that have occurred in the past and provide potential solutions to improve the quality of these studies to both the scientific and autistic communities. They include sample and measurement diversity, retention, outcome measures, analysis, and funding considerations. This understanding of the field is important for both scientific research and community engagement in the studies that include the autistic community.

Autism screening and diagnostic outcomes among toddlers born preterm

AIM

To examine the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up (M-CHAT-R/F), with follow-up screening and diagnostic outcomes for children born preterm. A secondary aim was to examine diagnostic evaluation attendance after screening to inform clinical practice.

METHOD

Using a cross-sectional design, 9725 toddlers (4951 males; 4774 females) whose gestational age was reported were screened at 15-month, 18-month, or 24-month well-child visits; screen-positive children were invited for an autism evaluation. Screening measure performance and diagnostic outcomes were evaluated according to preterm classification (Screening: nExtPreterm = 111; nVeryPreterm = 186; nModPreterm = 1122; nFullTerm = 8306; Evaluation: nExtPreterm = 27; nVeryPreterm = 21; nModPreterm = 86; nFullTerm = 301).

RESULTS

Screen-positive rates were highest for children born extremely preterm (51.35%) and lowest for children born at term (6.95%). Evaluation attendance for screen-positive cases did not differ according to preterm classification. Rates of autism diagnoses differed depending on preterm birth status: for children born extremely preterm, it was 16.05%; for children born very preterm, it was 2.00%; for children born moderately preterm, it was 2.89%; and for children born at term, it was 1.49%. M-CHAT-R/F sensitivity decreased with increasing gestational age, whereas specificity improved with increasing gestational age. Positive predictive value was highest for children born extremely preterm and children born at term. Negative predictive value was consistently strong across all groups. The likelihood ratio for positive screening increased with gestational age.

INTERPRETATION

The sensitivity and specificity of the M-CHAT-R/F are acceptable in toddlers born preterm. Autism screening-positive rates and prevalence increased with earlier preterm birth. Those born extremely preterm showed the greatest likelihood of an autism diagnosis; screening should not be delayed based on adjusted age.

The impact of paternal mental illness on child development: an umbrella review of systematic reviews and meta-analyses

Whilst there is growing evidence highlighting the importance of paternal mental illness (PMI) on child development, this relationship still remains under-studied and often over-looked. Considering the increasingly active role of fathers in their children's upbringing, a comprehensive overview of the impact of PMI on child development is overdue. This study aimed to combine and synthesise currently available evidence on the relationship between PMI and multiple domains of child development. Narrative synthesis of systematic reviews and meta-analyses on the relationship between PMI and child development (mental health and social, emotional, language, cognitive or adaptive behaviour), published between 1980 to December 2021, was conducted in line with PRISMA 2020 guidelines. Review quality was assessed based on AMSTAR-2 criteria and respective study confidence was interpreted in line with GRADE scoring. All relevant meta-analytic effect sizes were converted to odds ratios (OR) and grouped using a random effects model. Grouped meta-analyses saw PMI to have a significant, detrimental effect on all studied domains of child development [OR: 1.54; 95% CI (1.36-1.74)]. Subgroup analyses saw PMI affecting both internalising [OR: 1.62; 95% CI (1.27-2.08)] and externalising [OR: 1.63; 95% CI (1.28-2.08)] child behaviours to a similar extent. However, included reviews were of poor methodological quality, demonstrating either low or critically low confidence. These results show a consistent and influential effect of PMI on child development. The relationship between fathers' mental illness and child development warrants further investigation, as current research is limited in scope, particularly regarding cognitive domains of child development and non-affective PMI diagnoses.

Risk of Autism Spectrum Disorder (ASD) Among 18 to 48 Month Old Children: A Multi-Center Study in Qatar

Background. Little is known about autism spectrum disorder (ASD) in Qatar. The lack of consensus in ASD screening has led to differences in the reported prevalence with escalating rates over time. Objective(s). To screen for ASD and to identify associate factors among Qatary children aged 18 to 48 months. Methods. A cross-sectional study included 600 eligible children at 10 Primary Health Care Centers (PHCCs) in Qatar. Identification of ASD was based on the M-CHAT™ criteria. Results. The number of ASD screen-positive children in the M-CHAT™ was 25.13 per 10.000, and was significantly associated with older maternal age (10.5%) and history of neonatal hyperbilirubinemia (20.0%) [AOR] = 4.88; 95%[CI]: 1.50-16.30)]. The Odds of detecting ASD was lower in children below 2 years of age (AOR = 0.92; 95% CI: 0.87-0.98]). Conclusion. This study demonstrates the utility of M-CHAT™ for ASD screening in PHCCs. Identification of the factors associated with positive ASD screening can highlight areas suitable for future intervention.

Tocolytic treatment and maternal characteristics, obstetric outcomes, and offspring childhood outcomes among births at and after 37 weeks of gestation: the Japan environment and children's study

PURPOSE

To evaluate differences in maternal characteristics and obstetric and offspring childhood outcomes between births at and after 37 weeks of gestation (referred to as term and post-term births) according to the use of tocolytic treatment.

METHODS

Data for 63,409 women with singleton births at and after 37 weeks of gestation were analyzed using data from the Japan Environment and Children's Study (JECS). We compared maternal characteristics, obstetric outcomes, and offspring childhood outcomes between term and post-term births exposed and not exposed to tocolytic treatment. Additionally, multivariable logistic regression models were used to calculate adjusted odds ratios for offspring childhood outcomes with significant between-group differences in the univariable analysis, with term and post-term births without tocolytic agents as the reference group.

RESULTS

We observed differences in maternal characteristics and obstetric outcomes between term and post-term births exposed and not exposed to tocolytic treatment. The incidence of offspring childhood developmental disorders showed no significant between-group differences. However, participants exposed to tocolytic agents had higher incidence of offspring childhood allergic disorders. The adjusted odds ratio for any of the offspring childhood allergic disorders in term and post-term births with tocolytic agents was 1.08 (95% confidence interval, 1.03-1.13).

CONCLUSION

This study found no significant difference in the incidence of offspring developmental disorders between term and post-term births exposed and not exposed to tocolytic treatment. However, tocolytic treatment was associated with differences in maternal characteristics and obstetric outcomes, along with a marginal increase in the incidence of childhood allergic disorders in offspring.

Pre and perinatal predictors on autism spectrum disorders: a case-control study in the west of Iran

INTRODUCTION

The constellation of pre and perinatal predictors are introduced as predictor for autism spectrum disorders (ASD), however, the information about the direction and strength of these predictors are lacking in Western, Iran. The current study aimed to determine the pre and perinatal predictors of ASD among children in this region.

METHODS

This case-control study was conducted in Hamadan, Western Iran during January to March 2022. The study included 100 children with ASD who referred to the autism center as case group. Hundred children without ASD from registration system of health service centers were selected as control group and were matched (1:1) to cases by age and place of residency. A structured questionnaire about pre and perinatal predictors of ASD was developed by an expert panel. The questionnaire was administered by interviewing the mothers of children.

RESULTS

Boy gender (OR: 3.51, 95% CI: 1.74-7.10, p-value < 0.001), small for gestational age (SGA) (3.92, 1.64-9.39, 0.002), maternal diabetes (3.51, 1.03-24.95, 0.04) and family history of mental disorders (3.64, 1.18-11.27, 0.04) were identified as significant predictors in a multivariable analysis.

CONCLUSION

Our study emphasizes on the importance of screening and monitoring for ASD in the boys, those with history of SGA, from mothers with history of diabetes and with family history of mental disorders. Proposing the replication of findings emphasizes the necessity of conducting studies with larger sample sizes.

Neurodevelopmental outcomes after prenatal exposure to lamotrigine monotherapy in women with epilepsy: a systematic review and meta-analysis

BACKGROUND

Lamotrigine has become one of the most commonly prescribed antiseizure medications (ASM) in epileptic women during pregnancy and therefore requires regular updates regarding its safety. The aim of this study was to estimate the association between in utero exposure to lamotrigine monotherapy and the occurrence of neurodevelopmental outcomes.

METHODS

All comparative studies assessing the occurrence of neurodevelopmental outcomes after epilepsy-indicated lamotrigine monotherapy exposure during pregnancy were searched. First, references were identified through a snowballing approach, then, through electronic databases (Medline and Embase) from 2015 to June 2022. One investigator evaluated study eligibility and extracted data and a second independent investigator reviewed the meta-analysis (MA). A systematic review and random-effects model approach were performed using a collaborative WEB-based meta-analysis platform (metaPreg.org) with a registered protocol (osf.io/u4gva).

RESULTS

Overall, 18 studies were included. For outcomes reported by at least 4 studies, the pooled odds ratios and 95% confidence interval obtained with the number of exposed (N1) and unexposed children (N0) included were: neurodevelopmental disorders as a whole 0.84 [0.66;1.06] (N1 = 5,271; N0 = 22,230); language disorders or delay 1.16 [0.67;2.00] (N1 = 313; N0 = 506); diagnosis or risk of ASD 0.97 [0.61;1.53] (N1 = at least 5,262; N0 = 33,313); diagnosis or risk of ADHD 1.14 [0.75;1.72] (N1 = at least 113; N0 = 11,530) and psychomotor developmental disorders or delay 2.68 [1.29-5.56] (N1 = 163; N0 = 220). The MA of cognitive outcomes included less than 4 studies and retrieved a significant association for infants exposed to lamotrigine younger than 3 years old but not in the older age groups.

CONCLUSION

Prenatal exposure to lamotrigine monotherapy is not found to be statistically associated with neurodevelopmental disorders as a whole, language disorders or delay, diagnosis or risk of ASD and diagnosis or risk of ADHD. However, the MA found an increased risk of psychomotor developmental disorders or delay and cognitive developmental delay in less than 3 years old children. Nevertheless, these findings were based exclusively on observational studies presenting biases and on a limited number of included children. More studies should assess neurodevelopmental outcomes in children prenatally exposed to lamotrigine.

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

Background

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

Results

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

Conclusion

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

Reelin cells and sex-dependent synaptopathology in autism following postnatal immune activation

BACKGROUND AND PURPOSE

Autism spectrum disorders (ASD) are heterogeneous neurodevelopmental disorders with considerably increased risk in male infants born preterm and with neonatal infection. Here, we investigated the role of postnatal immune activation on hippocampal synaptopathology by targeting Reelin+ cells in mice with ASD-like behaviours.

EXPERIMENTAL APPROACH

C57/Bl6 mouse pups of both sexes received lipopolysaccharide (LPS, 1 mg·kg-1 ) on postnatal day (P) 5. At P45, animal behaviour was examined by marble burying and sociability test, followed by ex vivo brain MRI diffusion kurtosis imaging (DKI). Hippocampal synaptogenesis, number and morphology of Reelin+ cells, and mRNA expression of trans-synaptic genes, including neurexin-3, neuroligin-1, and cell-adhesion molecule nectin-1, were analysed at P12 and P45.

KEY RESULTS

Social withdrawal and increased stereotypic activities in males were related to increased mean diffusivity on MRI-DKI and overgrowth in hippocampus together with retention of long-thin immature synapses on apical dendrites, decreased volume and number of Reelin+ cells as well as reduced expression of trans-synaptic and cell-adhesion molecules.

CONCLUSION AND IMPLICATIONS

The study provides new insights into sex-dependent mechanisms that may underlie ASD-like behaviour in males following postnatal immune activation. We identify GABAergic interneurons as core components of dysmaturation of excitatory synapses in the hippocampus following postnatal infection and provide cellular and molecular substrates for the MRI findings with translational value.

Neurodevelopmental outcome of Italian preterm ELBW infants: an eleven years single center cohort

BACKGROUND

Preterm extremely low birth weight infants (ELBWi) are known to be at greater risk of developing neuropsychiatric diseases. Identifying early predictors of outcome is essential to refer patients for early intervention. Few studies have investigated neurodevelopmental outcomes in Italian ELBWi. This study aims to describe neurodevelopmental outcome at 24 months of corrected age in an eleven-year single-center cohort of Italian ELBWi and to identify early risk factors for adverse neurodevelopmental outcomes.

METHODS

All infants born with birth weight < 1000 g and admitted to the Neonatal Intensive Care Unit of the "Fondazione IRCCS Policlinico San Matteo" hospital in Pavia, Italy, from Jan 1, 2005 to Dec 31, 2015 were eligible for inclusion. At 24 months, Griffiths' Mental Developmental Scales Extended Revised (GMDS-ER) were administered. Neurodevelopmental outcome was classified as: normal, minor sequelae (minor neurological signs, General Quotient between 76 and 87), major sequelae (cerebral palsy; General Quotient ≤ 75; severe sensory impairment). Univariate and multivariate multinomial logistic regression models were performed to analyze the correlation between neonatal variables and neurodevelopmental outcome.

RESULTS

176 ELBWi were enrolled (mean gestational age 26.52 weeks sd2.23; mean birthweight 777.45 g sd142.89). 67% showed a normal outcome at 24 months, 17% minor sequelae and 16% major sequelae (4.6% cerebral palsy on overall sample). The most frequent major sequela was cognitive impairment (8.52%). In the entire sample the median score on the Hearing-Speech subscale was lower than the median scores recorded on the other subscales and showed a significantly weaker correlation to each of the other subscales of the GMDS-ER. Severely abnormal cUS findings (RRR 10.22 p 0.043) and bronchopulmonary dysplasia (RRR 4.36 p 0.008) were independent risk factors for major sequelae and bronchopulmonary dysplasia for minor sequelae (RRR 3.00 p 0.018) on multivariate multinomial logistic regression.

CONCLUSIONS

This study showed an improvement in ELBWI survival rate without neurodevelopmental impairment at 24 months compared to previously reported international cohorts. Cognitive impairment was the most frequent major sequela. Median scores on GMDS-ER showed a peculiar developmental profile characterized by a selective deficit in the language domain. Severely abnormal cUS findings and bronchopulmonary dysplasia were confirmed as independent risk factors for major sequelae.

Extremely preterm birth and autistic traits in young adulthood: the EPICure study

Background

A high prevalence of autism spectrum disorder is reported in children born extremely preterm (EP), but an even larger proportion of survivors are affected by subclinical difficulties than meet diagnostic criteria. The aims of this study were to investigate autistic traits associated with the broader autism phenotype in a cohort of young adults born EP, and explore how these traits relate to emotion recognition, empathy and autism symptom presentation in childhood. The prevalence of autism diagnoses was also investigated.

Methods

One hundred and twenty-nine young adults born before 26 weeks of gestation and 65 term-born controls participated in the 19-year follow-up phase of the EPICure studies. In addition to a clinical interview, participants completed the Broader Autism Phenotype Questionnaire (BAPQ), the Empathy Quotient questionnaire, and the Frankfurt Test and Training of Facial Affect Recognition. The Social Communication Questionnaire (SCQ) was completed by the participants’ parents at age 11 years.

Results

EP born young adults scored significantly higher on the BAPQ in comparison with their term-born peers, indicating greater autistic traits. Among EP participants, BAPQ scores were correlated with SCQ scores in childhood (r = 0.484, p < 0.001). EP young adults had significantly lower scores in emotion recognition and empathy in comparison with controls; however, this effect was mediated by IQ. At 19 years, a diagnosis of autism was reported by 10% of EP participants versus 1.6% of controls, whereas 31% of EP participants scored above the cut-off for the broader autism phenotype in comparison with 8.5% of term-born controls.

Limitations

The high attrition of EP participants from lower socio-economic backgrounds and with lower cognitive functioning may have led to an underrepresentation of those presenting with difficulties associated with autism.

Conclusions

A larger proportion of EP survivors are affected by difficulties associated with autism than have confirmed diagnoses, with a moderate correlation between autism symptom scores in childhood and autistic traits in young adulthood. EP young adults had significantly higher autism symptom scores and a larger proportion had a diagnosis of autism than controls. Screening for autistic traits at set points throughout childhood will help identify those EP individuals at risk of social difficulties who may benefit from intervention.

Supplementary information

The online version contains supplementary material available at 10.1186/s13229-021-00414-0.