Pregnancy Intervals and Autism

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Pregnant_woman2A study that was recently published in the Journal of the American Academy of Child and Adolescent Psychiatry found that children conceived either less than one year or more than five years after the birth of their prior sibling were more likely to be autistic than children who were conceived between two to five years after their last sibling. The study was one of the most comprehensive ever to study autism and Asperger’s treatment.

The study, which was researched at Columbia University, used data from the Finnish Prenatal Study of Autism. Using data collected from 7,371 children born between the years of 1987 and 2005, researchers found that a third of the children overall became diagnosed with autism. The study used information gathered from several national registries to compare the pregnancy intervals between children diagnosed with autism and Asperger’s syndrome and those who did not develop a form of autism spectrum disorder.

The childhood study found that the risk of an autism diagnosis for children conceived less than one year following a sibling’s birth was one and a half times higher than those conceived 24-59 months after a sibling’s birth. In addition, children conceived from 60 months to120 months after their sibling were 30% more likely to be diagnosed with autism. Finally, the study concluded that for children born two years after the birth of their closest sibling, the risk of autism and Asperger’s syndrome rose to 40%.

The child psychiatry study took into account other factors that might contribute to autism as well, including both parents’ ages, the prior number of siblings and each child’s family history of autism and Asperger’s, which has already been linked to genetics.

Dr. Keely Cheslack-Postava, who led the study, stated that while the study provided intriguing new information in the field of behavioral health services, it was not evidence that the spacing of pregnancy was a direct cause of autism spectrum disorder. Instead, Cheslack-Postava concluded that birth intervals were instead a proxy of other factors that could be more directly related to a child’s development to ASD. The most important finding of the study was the link between certain prenatal factors and their related outcomes after birth.

Dr. Alan Brown, the senior author of the study determined that the study provides evidence that environmental factors that occur near or during the pregnancy and the prenatal period can play a role in the development of ASD. The study also showed the importance of a large sample set for studies of child psychiatry. The number of pregnancies studied and amount of data collected during pregnancy was one of the largest in a study of this scope and exemplified the importance of national databases of reproductive factors and psychiatric diagnoses.