title: [Environmental risk factors for autism spectrum disorders in children].
abstract: OBJECTIVE
  To investigate the environmental risk factors for autism spectrum disorders (ASD) in children.
  
  
  METHODS
  In this case-control study, 81 boys with ASD, 74 boys with global developmental delay (GDD), and 163 healthy boys were enrolled. A self-designed nurturing environment questionnaire was used to record general demographic data, family social-economic status, parents' living habits and environmental exposure, maternal health status during pregnancy, birth situations, and rearing environment after birth. Multivariate logistic regression was used to identify environmental risk factors for ASD and GDD.
  
  
  RESULTS
  Multivariate logistic regression analysis showed that six environmental risk factors such as maternal occupational toxicant exposure, diseases during pregnancy and a history of passive smoking, children's birth places, the frequency of outdoor activities in the second year after birth, and the opportunities to communicate with other age-matched children were significantly associated with the incidence of ASD (OR=20.67, 3.559, 2.422, 2.646, 23.820, and 5.081, respectively; P<0.05). Among the above six risk factors, passive smoking during pregnancy, the opportunities to communicate with their peers, and the frequency of outdoor activities in the second year after birth were also significantly associated with the incidence of GDD (P<0.05).
  
  
  CONCLUSIONS
  Maternal occupational toxicant exposure, diseases during pregnancy, and low level of children's birth places may be the specific risk factors associated with ASD, and passive smoking during pregnancy, fewer opportunities to communicate with their peers, and fewer outdoor activities in the second year after birth are non-specific risk factors for ASD, indicating that the development of ASD may be influenced by both genes and environmental factors.
authors.affiliation: Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China. shaojie@zju.edu.cn.
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.forename: Jian-Ying
authors.initials: JY
authors.lastname: Zhan
authors.forename: Jie
authors.initials: J
authors.lastname: Shao
mesh_terms: D000067877:Autism Spectrum Disorder / Q000209:etiology*; D016022:Case-Control Studies; D002675:Child, Preschool; D002658:Developmental Disabilities / Q000209:etiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D018811:Maternal Exposure; D011247:Pregnancy; D012307:Risk Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects
chemical_list: D014028:Tobacco Smoke Pollution