title: Early growth patterns in children with autism.
abstract: BACKGROUND
  Case-control studies have found increased head growth during the first year of life in children with autism spectrum disorder. Length and weight have not been as extensively studied, and there are few studies of population-based samples.
  
  
  METHODS
  The study was conducted in a sample of 106,082 children from the population-based Norwegian Mother and Child Cohort. The children were born in 1999-2009; by the end of follow-up on 31 December 2012, the age range was 3.6 through 13.1 years (mean 7.4 years). Measures were obtained prospectively until age 12 months for head circumference and 36 months for length and weight. We compared growth trajectories in autism spectrum disorder cases and noncases using Reed first-order models.
  
  
  RESULTS
  Subjects included 376 children (310 boys and 66 girls) with specialist-confirmed autism spectrum disorder. In boys with autism spectrum disorder, mean head growth was similar to that of other boys, but variability was greater, and 8.7% had macrocephaly (head circumference > 97th cohort percentile) by 12 months of age. Autism spectrum disorder boys also had slightly increased body growth, with mean length 1.1 cm above and mean weight 300 g above the cohort mean for boys at age 12 months. Throughout the first year, the head circumference of girls with autism spectrum disorder was reduced-by 0.3 cm at birth and 0.5 cm at 12 months. Their mean length was similar to that of other girls, but their mean weight was 150-350 g below at all ages from birth to 3 years. The reductions in mean head circumference and weight in girls with autism spectrum disorder appear to be driven by those with intellectual disability, genetic disorders, and epilepsy.
  
  
  CONCLUSIONS
  Growth trajectories in children with autism spectrum disorder diverge from those of other children and the differences are sex specific. Previous findings of increased mean head growth were not replicated.
authors.affiliation: Centre for Paediatric Epidemiology and Biostatistics, UCL Institute of Child Health, London, United Kingdom. pal.suren@fhi.no
authors.forename: Pål
authors.initials: P
authors.lastname: Surén
authors.forename: Camilla
authors.initials: C
authors.lastname: Stoltenberg
authors.forename: Michaeline
authors.initials: M
authors.lastname: Bresnahan
authors.forename: Deborah
authors.initials: D
authors.lastname: Hirtz
authors.forename: Kari Kveim
authors.initials: KK
authors.lastname: Lie
authors.forename: W Ian
authors.initials: WI
authors.lastname: Lipkin
authors.forename: Per
authors.initials: P
authors.lastname: Magnus
authors.forename: Ted
authors.initials: T
authors.lastname: Reichborn-Kjennerud
authors.forename: Synnve
authors.initials: S
authors.lastname: Schjølberg
authors.forename: Ezra
authors.initials: E
authors.lastname: Susser
authors.forename: Anne-Siri
authors.initials: AS
authors.lastname: Oyen
authors.forename: Leah
authors.initials: L
authors.lastname: Li
authors.forename: Mady
authors.initials: M
authors.lastname: Hornig
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001827:Body Height / Q000502:physiology*; D001835:Body Weight / Q000502:physiology*; D002648:Child; D002657:Child Development / Q000502:physiology*; D002659:Child Development Disorders, Pervasive / Q000503:physiopathology*; D002675:Child, Preschool; D005260:Female; D006257:Head / Q000254:growth & development*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009664:Norway