More of Autsim's possible links

Children who are firstborn or breech or whose mothers are 35 or older when giving birth are at significantly greater risk for developing an autism spectrum disorder.

In the April 27, 2009, online issue of the journal Pediatrics, the researchers showed that women who give birth at 35 or older are 1.7 times more likely to have a child with an autism spectrum disorder (ASD), compared with women between the ages of 20-34. Children diagnosed with ASD also were nearly 1.8 times more likely to be the firstborn child, the researchers found.

Although they didn't identify a causal relationship between breech births and autism, children diagnosed with the disorder were more than twice as likely to have been a breech presentation, meaning they were not born head first.

The study looked at 8-year-old children in Utah's three most populous counties—Salt Lake, Davis, and Utah—and used nationally accepted criteria for an ASD classification. The researchers compared birth records for children identified with an ASD with unaffected children born in those three counties in 1994. Of that group, 196 were identified with an ASD. Birth certificates were available for 132 of those children, and the researchers examined those records for possible prenatal, perinatal, and neonatal risk factors related to ASD.

Their investigation showed that the mother's age when giving birth (older than 34), breech presentation, and being firstborn were significant risk factors for the development of an ASD. The researchers also identified a small but significant relationship between the increased duration of education among mothers of those children.

Bonnie - the aspect of women over 35 is compelling, especially since recent studies showed older men having children shows a greater rate of autism as well.