A Prospective Ultrasound Study of Prenatal Growth in Infant Siblings of Children With Autism

Fetal brain growth and infant autistic traits

BACKGROUND

Structural differences exist in the brains of autistic individuals. To date only a few studies have explored the relationship between fetal brain growth and later infant autistic traits, and some have used fetal head circumference (HC) as a proxy for brain development. These findings have been inconsistent. Here we investigate whether fetal subregional brain measurements correlate with autistic traits in toddlers.

METHODS

A total of 219 singleton pregnancies (104 males and 115 females) were recruited at the Rosie Hospital, Cambridge, UK. 2D ultrasound was performed at 12-, 20- and between 26 and 30 weeks of pregnancy, measuring head circumference (HC), ventricular atrium (VA) and transcerebellar diameter (TCD). A total of 179 infants were followed up at 18-20 months of age and completed the quantitative checklist for autism in toddlers (Q-CHAT) to measure autistic traits.

RESULTS

Q-CHAT scores at 18-20 months of age were positively associated with TCD size at 20 weeks and with HC at 28 weeks, in univariate analyses, and in multiple regression models which controlled for sex, maternal age and birth weight.

LIMITATIONS

Due to the nature and location of the study, ascertainment bias could also have contributed to the recruitment of volunteer mothers with a higher than typical range of autistic traits and/or with a significant interest in the neurodevelopment of their children.

CONCLUSION

Prenatal brain growth is associated with toddler autistic traits and this can be ascertained via ultrasound starting at 20 weeks gestation.

Parent-child interaction and developmental outcomes in children with typical and elevated likelihood of autism

BACKGROUND

Early parent-child interactions have a critical impact on the developmental outcomes of the child. It has been reported that infants with a family history of autism and their parents may engage in different patterns of behaviours during interaction compared to those without a family history of autism. This study investigated the association of parent-child interactions with child developmental outcomes of those with typical and elevated likelihood of autism.

METHOD

This longitudinal study investigated the relationship between global attributes of parent-child interaction and the developmental outcomes of infant siblings with elevated likelihood (EL: n = 29) or typical likelihood (TL: n = 39) of developing autism. Parent-child interactions were recorded during a session of free-play when the infants were six months of age. Developmental assessments were carried out when the children were 12 and 24 months of age.

RESULTS

The intensity of mutuality was significantly higher in the TL group than in the EL group, and developmental outcomes were poorer in the EL group when compared to the TL group. Positive associations between parent-child interaction scores at six months and developmental outcomes at 12 months were observed only in the TL group. However, in the EL group, higher levels of infant positive affect and attentiveness paid to the caregiver is associated with lower autism symptoms. Due to the sample size and design of the study, the findings must be viewed as indicative.

CONCLUSION

This preliminary investigation demonstrated differences in the association between parent-child interaction quality and developmental outcomes for children with typical and elevated likelihood for autism. Future studies should combine micro-analytic and macro-analytic approaches to parent-child interaction to further examine the nature of this relationship.

OUP accepted manuscript

Multiple pieces of evidence support the prenatal predisposition of autism spectrum disorder (ASD). Nevertheless, robust data about abnormalities in foetuses later developing into children diagnosed with ASD are lacking. Prenatal ultrasound is an excellent tool to study abnormal foetal development as it is frequently used to monitor foetal growth and identify foetal anomalies throughout pregnancy. We conducted a retrospective case-sibling-control study of children diagnosed with ASD (cases); their own typically developing, closest-in-age siblings (TDS); and typically developing children from the general population (TDP), matched by year of birth, sex and ethnicity to investigate the association between ultrasonography foetal anomalies and ASD. The case group was drawn from all children diagnosed with ASD enrolled at the National Autism Research Center of Israel. Foetal ultrasound data from the foetal anatomy survey were obtained from prenatal ultrasound clinics of Clalit Health Services in southern Israel. The study comprised 659 children: 229 ASD, 201 TDS and 229 TDP. Ultrasonography foetal anomalies were found in 29.3% of ASD cases versus only 15.9% and 9.6% in the TDS and TDP groups [adjusted odds ratio (aOR) = 2.23, 95% confidence interval (CI) = 1.32-3.78, and aOR = 3.50, 95%CI = 2.07-5.91, respectively]. Multiple co-occurring ultrasonography foetal anomalies were significantly more prevalent among ASD cases. Ultrasonography foetal anomalies in the urinary system, heart, and head and brain were the most significantly associated with ASD diagnosis (aORUrinary = 2.08, 95%CI = 0.96-4.50 and aORUrinary = 2.90, 95%CI = 1.41-5.95; aORHeart = 3.72, 95%CI = 1.50-9.24 and aORHeart = 8.67, 95%CI = 2.62-28.63; and aORHead&Brain = 1.96, 95%CI = 0.72-5.30 and aORHead&Brain = 4.67, 95%CI = 1.34-16.24; versus TDS and TDP, respectively). ASD females had significantly more ultrasonography foetal anomalies than ASD males (43.1% versus 25.3%, P = 0.013) and a higher prevalence of multiple co-occurring ultrasonography foetal anomalies (15.7% versus 4.5%, P = 0.011). No sex differences were seen among TDS and TDP controls. ASD foetuses were characterized by a narrower head and a relatively wider ocular-distance versus TDP foetuses (ORBPD = 0.81, 95%CI = 0.70-0.94, and aOROcular distance = 1.29, 95%CI = 1.06-1.57). Ultrasonography foetal anomalies were associated with more severe ASD symptoms. Our findings shed important light on the multiorgan foetal anomalies associated with ASD.

Association Between Abnormal Fetal Head Growth and Autism Spectrum Disorder

OBJECTIVE

Despite evidence for the prenatal onset of abnormal head growth in children with autism spectrum disorder (ASD), studies on fetal ultrasound data in ASD are limited and controversial.

METHOD

We conducted a longitudinal matched case-sibling-control study on prenatal ultrasound biometric measures of children with ASD, and 2 control groups: (1) their own typically developed sibling (TDS) and (2) typically developed population (TDP). The cohort comprised 528 children (72.7% male), 174 with ASD, 178 TDS, and 176 TDP.

RESULTS

During the second trimester, ASD and TDS fetuses had significantly smaller biparietal diameter (BPD) than TDP fetuses (adjusted odds ratio for the z score of BPD [aOR_zBPD] = 0.685, 95% CI = 0.527-0.890, and aOR_zBPD = 0.587, 95% CI = 0.459-0.751, respectively). However, these differences became statistically indistinguishable in the third trimester. Interestingly, head biometric measures varied by sex, with male fetuses having larger heads than female fetuses within and across groups. A linear mixed-effect model assessing the effects of sex and group assignment on fetal longitudinal head growth indicated faster BPD growth in TDS versus both ASD and TDP in male fetuses (β = 0.084 and β = 0.100 respectively; p < .001) but not in female fetuses, suggesting an ASD-sex interaction in head growth during gestation. Finally, fetal head growth showed conflicting correlations with ASD severity in male and female children across different gestation periods, thus further supporting the sex effect on the association between fetal head growth and ASD.

CONCLUSION

Our findings suggest that abnormal fetal head growth is a familial trait of ASD, which is modulated by sex and is associated with the severity of the disorder. Thus, it could serve as an early biomarker for ASD.

A white paper on a neurodevelopmental framework for drug discovery in autism and other neurodevelopmental disorders

In the last decade there has been a revolution in terms of genetic findings in neurodevelopmental disorders (NDDs), with many discoveries critical for understanding their aetiology and pathophysiology. Clinical trials in single-gene disorders such as fragile X syndrome highlight the challenges of investigating new drug targets in NDDs. Incorporating a developmental perspective into the process of drug development for NDDs could help to overcome some of the current difficulties in identifying and testing new treatments. This paper provides a summary of the proceedings of the 'New Frontiers Meeting' on neurodevelopmental disorders organised by the European College of Neuropsychopharmacology in conjunction with the Innovative Medicines Initiative-sponsored AIMS-2-TRIALS consortium. It brought together experts in developmental genetics, autism, NDDs, and clinical trials from academia and industry, regulators, patient and family associations, and other stakeholders. The meeting sought to provide a platform for focused communication on scientific insights, challenges, and methodologies that might be applicable to the development of CNS treatments from a neurodevelopmental perspective. Multidisciplinary translational consortia to develop basic and clinical research in parallel could be pivotal to advance knowledge in the field. Although implementation of clinical trials for NDDs in paediatric populations is widely acknowledged as essential, safety concerns should guide each aspect of their design. Industry and academia should join forces to improve knowledge of the biology of brain development, identify the optimal timing of interventions, and translate these findings into new drugs, allowing for the needs of users and families, with support from regulatory agencies.

The associations between autistic and communication traits in parents and developmental outcomes in children at familial risk of autism at 6 and 24 months of age

BACKGROUND

Several studies have explored relationships between parent broader autism phenotype and offspring communication, and have reported that autistic-like traits in parents are related to offspring communication difficulties and autism severity. However, past research has focused on studying such associations in childhood and we know very little about them in infancy. With accumulating evidence that interventions administered during infancy may be most effective in reducing ASD symptoms, it is imperative to examine whether relationships between parent autistic-like traits and child communication appear even earlier during this critical period of life.

METHOD

This longitudinal study collected data from infant siblings of autistic children (N = 32) and infants with no family history of autism (N = 45) to explore how autistic-like traits in parents related to child developmental outcomes during infancy.

RESULTS

Parental communication difficulties and autistic-like traits were found to be associated with a range of child behaviours in the first two years of life, including social-emotional difficulties at 6 and 24 months, lower communication and emerging cognition at 24 months, and increased autistic behaviours at 24 months.

CONCLUSIONS

Based on the results, it appears that some of the difficulties seen in parents are relayed to children genetically. These findings contribute to ASD research concerning early communication development in children and heritability of ASD traits and may have important implications in monitoring child development. Furthermore, since the current study found a significant association between autistic traits in parents and child social-emotional behaviour as early as 6 months of age, it provides evidence of the value of assessing interventions that target infancy.

Machine learning analysis of pregnancy data enables early identification of a subpopulation of newborns with ASD

To identify newborns at risk of developing ASD and to detect ASD biomarkers early after birth, we compared retrospectively ultrasound and biological measurements of babies diagnosed later with ASD or neurotypical (NT) that are collected routinely during pregnancy and birth. We used a supervised machine learning algorithm with a cross-validation technique to classify NT and ASD babies and performed various statistical tests. With a minimization of the false positive rate, 96% of NT and 41% of ASD babies were identified with a positive predictive value of 77%. We identified the following biomarkers related to ASD: sex, maternal familial history of auto-immune diseases, maternal immunization to CMV, IgG CMV level, timing of fetal rotation on head, femur length in the 3rd trimester, white blood cell count in the 3rd trimester, fetal heart rate during labor, newborn feeding and temperature difference between birth and one day after. Furthermore, statistical models revealed that a subpopulation of 38% of babies at risk of ASD had significantly larger fetal head circumference than age-matched NT ones, suggesting an in utero origin of the reported bigger brains of toddlers with ASD. Our results suggest that pregnancy follow-up measurements might provide an early prognosis of ASD enabling pre-symptomatic behavioral interventions to attenuate efficiently ASD developmental sequels.

A methodological review of fetal neurosonographic studies: New directions in assessment of neurodevelopmental risk for mental health problems

Most mental disorders are now considered to have neurodevelopmental origins, with a growing body of research pointing to neural alterations that predate birth. However, lack of established methods for reliable investigation of fetal brain development has limited research into early neural vulnerability. Using a systematic approach and quantitative evaluation of study methodology, we review neurosonographic studies of fetal brain structure with objective quality measures. A total of 81 studies were identified. High quality studies were identified for measurement of the corpus callosum, cerebellum, vermis, ventricles and frontal cortex, with reference ranges provided to facilitate future clinical research. Fewer and lower quality studies were available for subcortical structures, prompting a need for further research to create reliable reference ranges. Development and adoption of reference ranges for fetal brain structures should facilitate future research in neurosonographic evaluation of fetal brain development and lead to a better understanding of neurodevelopmental risk and resilience processes for mental disorders.

Antenatal ultrasound value in risk calculation for Autism Spectrum Disorder: A systematic review to support future research

There is a growing research interest on the antenatal features of children with neurodevelopmental disorders. Indeed, it has been proved that the neurodevelopment is, at least partly, affected by processes occurring in fetal life and that the early neurodevelopmental disorders identification is essential to optimize long-term outcomes. This systematic review aims to summarize findings on antenatal ultrasound data, which are or might be considered early risk indexes of postnatal social impairments. We conducted systematic searches in Pubmed and PsychINFO databases to identify studies including fetal ultrasound measurements and postnatal neurodevelopmental outcome assessment. The bibliographic search included 3203 articles but after the assessment of the eligibility conducted by two independent researchers, only 26 studies were selected. Some alterations in ultrasound antenatal measurements (such as biophysical data, nuchal thickness and enlargement of cerebral ventricles) have been associated to autism spectrum disorder. However, data are still limited, controversial and not specific. Reported data are here discussed to strongly support studies on fetuses at high risk for autism spectrum disorder.

Skeletal Growth Dysregulation in Australian Male Infants and Toddlers With Autism Spectrum Disorder

Recent findings suggest that children with Autism Spectrum Disorder (ASD) are larger in size for head circumference (HC), height, and weight compared to typically developing (TD) children; however, little is known about their rate of growth, especially in height and weight. The current study aimed to: (a) confirm and extend upon previous findings of early generalized overgrowth in ASD; and (b) determine if there were any differences in the rate of growth between infants and toddlers with ASD compared to their TD peers. Measurements of HC, height, and weight were available for 135 boys with ASD and 74 TD boys, from birth through 3 years of age. Size and growth rate in HC, height, and weight were analyzed using a linear mixed-effects model. Infants with ASD were significantly smaller in size at birth for HC, body length, and weight compared to TD infants (all P < 0.05); however, they grew at a significantly faster rate in HC and height in comparison to the TD children (P < 0.001); there was no significant difference between the groups in growth rate for weight (P > 0.05). The results confirmed that male infants and toddlers with ASD exhibit skeletal growth dysregulation early in life. Autism Res 2018, 11: 846-856. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

Recent findings suggest that infants with Autism Spectrum Disorder (ASD) are smaller in size at birth compared to typically developing infants but grow larger than their peers during the first year. Little is known about their rate of growth, especially for height and weight. Our findings confirmed that infants with ASD are smaller in size at birth for head circumference (HC), height, and weight, but grow at a faster rate in HC and height than their peers from birth to 3 years.

A prospective study of fetal head growth, autistic traits and autism spectrum disorder

Altered trajectories of brain growth are often reported in Autism Spectrum Disorder (ASD), particularly during the first year of life. However, less is known about prenatal head growth trajectories, and no study has examined the relation with postnatal autistic symptom severity. The current study prospectively examined the association between fetal head growth and the spectrum of autistic symptom severity in two large population-based cohorts, including a sample of individuals with clinically diagnosed ASD. This study included 3,820 children from two longitudinal prenatal cohorts in The Netherlands and Australia, comprising 60 individuals with a confirmed diagnosis of ASD. Latent growth curve models were used to examine the relationship between fetal head circumference measured at three different time points and autistic traits measured in postnatal life using either the Social Responsiveness Scale or the Autism-Spectrum Quotient. While lower initial prenatal HC was weakly associated with increasing autistic traits in the Dutch cohort, this relationship was not observed in the Australian cohort, nor when the two cohorts were analysed together. No differences in prenatal head growth were found between individuals with ASD and controls. This large population-based study identified no consistent association across two cohorts between prenatal head growth and postnatal autistic traits. Our mixed findings suggest that further research in this area is needed. Autism Res 2018, 11: 602-612. © 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc.

LAY SUMMARY

It is not known whether different patterns of postnatal brain growth in Autism Spectrum Disorder (ASD) also occurs prenatally. We examined fetal head growth and autistic symptoms in two large groups from The Netherlands and Australia. Lower initial prenatal head circumference was associated with autistic traits in the Dutch, but not the Australian, group. No differences in head growth were found in individuals with ASD and controls when the data was combined. Our mixed findings suggest that more research in this area is needed.

Acoustic Properties of Cries in 12-Month Old Infants at High-Risk of Autism Spectrum Disorder

There is preliminary evidence that infant siblings of children with Autism Spectrum Disorder (ASD) have an atypical pattern of cry, characterized by higher fundamental frequency and increased dysphonation. This prospective study collected multiple cry samples of 12-month old siblings of children with ASD (n = 22, 'high-risk' group) and 12-month olds with no family history of ASD (n = 27, 'low risk' group). While there was no difference between groups in the fundamental frequency or degree of phonation of the cry samples, the duration of each cry unit was significantly shorter in the high-risk siblings (p < .05). The six infant siblings who received a diagnosis of ASD at age two had amongst the shortest recorded cry durations.