No evidence of early head circumference enlargements in children later diagnosed with autism in Israel

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.

Correlation analysis of maternal condition during pregnancy with head circumference and autism spectrum disorder: A propensity score-matched study

To determine whether health status during pregnancy is associated with autism spectrum disorder (ASD) and abnormal head circumference (HC) in the offspring. This study included 41 Han children with ASD who visited the Children's Health Clinic of the Second Hospital of Shandong University between March 2018 and February 2019, and 264 Han children with typical development (TD) who visited the clinic during the same period. Physical measurements were performed on the children. The questionnaire obtained information on maternal risk factors that may be related to the increased risk of ASD and folic acid (FA) supplementation. We designed an observational case-control study using propensity score matching and multivariate logistic regression analysis. The incidence of macrocephaly in the ASD group was 22.0%, significantly higher than that in the TD group (1.8%). The incidence of microcephaly in the ASD group was 17.1% (n = 7), significantly higher than that in the TD group (1.8%). The differences between the comparisons were statistically significant. Maternal FA supplementation during pregnancy was significantly associated with ASD (P < .05), with an odds ratio (95% confidence interval of 3.69 (1.76, 7.76)). Also was associated with macrocephaly (P < .05), odds ratio (95% confidence interval) were 8.13 (1.63, 40.61) and 4.16 (1.18, 14.60), respectively. The incidence of abnormal HC was higher in the ASD group than that in the TD group. Maternal FA supplementation during pregnancy may be negatively associated with the occurrence of ASD and abnormal HC in the offspring. Further examination of the role of maternal health status in the etiology of ASD is recommended.

Factors in Infancy That May Predict Autism Spectrum Disorder

The global increase in the prevalence of ASD (Autism Spectrum Disorder) is of great medical importance, but the reasons for this increase are still unknown. This study sought to identify possible early contributing factors in children who were later diagnosed with ASD. In this retrospective cohort study, postnatal records of 1105 children diagnosed with ASD were analyzed to determine if any signs of ASD could be found in a large database of births and well-baby care programs. We compared the recordings of typically developing children and analyzed the differences statistically. Rapid increases in weight, height, and head circumference during early infancy predict the development of ASD. In addition, low birth weight, older maternal age, and increased weight and height percentiles at six months of age together predict the development of ASD. At two years of age, these four parameters, in addition to impaired motor development, can also predict the development of ASD. These results suggest that the recent increase in ASD prevalence is associated with the "obesity epidemic" and with recommendations of supine sleeping to prevent Sudden Infant Death Syndrome, associated with atypical neural network development in the brain.

Head circumference trends in autism between 0 and 100 months

LAY ABSTRACT

Summaries of studies that have measured head size in those with autism, known as meta-analyses, currently exist. However, this approach does not adequately explain extreme cases (such as those with extremely small, or extremely large, head size). Because of this, we obtained all available published data measuring head size (12 studies). The data from each study were then combined to make a larger dataset. We found that females with autism aged 12-17 months had, on average, smaller head sizes. Otherwise, average head size was not atypical in autism. However, we found that males with autism were more likely to have extreme head sizes at birth and between 60 and 100 months, a small head between 6 and 11 months, and a large head between 12 and 17 months. Females with autism were more likely to have extreme head sizes between 36 and 59 months and were less likely at birth. Our approach was able to measure the influence of age and biological sex on head size in autism, as well as the frequency of extreme cases of head size in autism. These results add to what we already know about head size in autism.

The Predictive Value of Head Circumference Growth during the First Year of Life on Early Child Traits

Atypical head circumference (HC) growth has been associated with neurodevelopmental disorders. However, whether it is associated with specific aspects of development in early childhood in the general population is unknown. The objective of this study was to assess the predictive value of HC growth as an early biomarker of behavioral traits. We examined longitudinal associations between HC growth from 0 to 12 months and temperament, cognitive, and motor development at 24 months. A subsample of healthy children (N = 756) was drawn from the 3D (Design, Develop, Discover) cohort study. Early HC growth was modeled with latent growth curve analysis. Greater postnatal HC growth predicted lower temperamental effortful control and lower surgency/extraversion in boys. HC growth did not predict cognitive or fine motor scores, but did predict greater gross motor skills in boys. No significant effect of HC growth was found in girls. This study is the first to demonstrate an association between postnatal HC growth and specific aspects of child development in a healthy population. Results suggest HC growth overshadows brain mechanisms involved in behavioral traits in early infancy. Whether links are maintained throughout development and the mechanisms involved correspond to traits found in atypical populations remains to be studied.

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.

Errant gardeners: glial-cell-dependent synaptic pruning and neurodevelopmental disorders

The final stage of brain development is associated with the generation and maturation of neuronal synapses. However, the same period is also associated with a peak in synapse elimination - a process known as synaptic pruning - that has been proposed to be crucial for the maturation of remaining synaptic connections. Recent studies have pointed to a key role for glial cells in synaptic pruning in various parts of the nervous system and have identified a set of critical signalling pathways between glia and neurons. At the same time, brain imaging and post-mortem anatomical studies suggest that insufficient or excessive synaptic pruning may underlie several neurodevelopmental disorders, including autism, schizophrenia and epilepsy. Here, we review current data on the cellular, physiological and molecular mechanisms of glial-cell-dependent synaptic pruning and outline their potential contribution to neurodevelopmental disorders.