Fetal Head Growth in Children with Autistic Traits and Autism Spectrum Disorder

Saturday, May 14, 2016: 11:30 AM-1:30 PM
Hall A (Baltimore Convention Center)
L. M. Blanken1, A. Dass2, G. Alvares2, J. van der Ende3, M. Maybery4, C. Dissanayake5, C. Pennel6, M. Hickey7, F. Verhulst3, H. Tiemeier3, A. Whitehouse8 and T. J. White9, (1)Erasmus Medical Center - Sophia Children's Hospital, Leiden, Netherlands, (2)Telethon Kids Institute, West Perth, Australia, (3)Department of Child and Adolescent Psychiatry/Psychology, Erasmus MC-Sophia, Rotterdam, Netherlands, (4)University of Western Australia, Perth, Australia, (5)Olga Tennison Autism Research Centre, La Trobe University, Melbourne, Australia, (6)The University of Western Australia, Crawley, Australia, (7)Department of Obstetrics of Gynaecology and Obstetrics, University of Melbourne, Melbourne, Australia, (8)University of Western Australia, West Perth, WA, Australia, (9)Erasmus University Medical Centre, Rotterdam, Netherlands
Background:  Altered trajectories of brain development are often reported in Autism Spectrum Disorder (ASD), particularly early brain overgrowth in the first year of life (Hazlett, Poe et al. 2011). However, less is known about prenatal head growth trajectories. The few studies available have small sample sizes, typically depend on retrospectively collected ultrasound data and do not include repeated measurements of growth (Whitehouse, Hickey et al. 2011). While there is increasing support for the notion that ASD lies at the extreme end of a continuum of autistic traits, and that characteristics of the neurobiology may form a continuum as well (Blanken, Mous et al. 2015), there are no studies that investigate growth characteristics of the full spectrum of symptom severity (Constantino and Todd 2003). 

Objectives:  The objective of the current study is to prospectively evaluate prenatal head growth in children from the general population that later develop autistic traits. A second objective is to compare prenatal head growth between children with clinically diagnosed ASD and typically developing children.

Methods:  This study included over 5,700 children participating  in two large longitudinal prenatal cohorts, including more than 80 children with a confirmed diagnosis of ASD. Fetal head circumference (HC) was measured repeatedly during pregnancy using ultrasound. Autistic traits were measured with the Social Responsiveness Scale and the Autism Quotient. A diagnosis of ASD was based on mother report and confirmed with medical records. Additionally,  ultrasounds were retrospectively collected for 45 children with ASD at a clinical research center. Longitudinal HC measurements at three time points were analyzed using a Latent Growth curve model approach to assess the relation of prenatal growth on autistic traits measured later in life.

Results:  Preliminary analyses suggested an inverse relationship between prenatal head growth and autistic traits later in life. Children with more autistic traits showed HC growth curves that were characterized by smaller slopes and intercepts. 

Conclusions:  To our knowledge, this is the first large population-based study looking into prenatal brain growth and autistic traits. Preliminary results suggest that atypical brain growth in ASD may start in utero. Additional analyses comparing prenatal head growth between children with clinically diagnosed ASD and typically developing children will be conducted.