Autism linked to breech births and older mums
CHILDREN born in a breech position or to older moms were more likely to be diagnosed with autism by age 8 in the latest study to examine the role of environment and genes in developmental disorders.
Psychiatrists from the University of Utah School of Medicine in Salt Lake City compared medical records for 132 children with autism with those of 13,200 children without the disorder who were also born in 1994. They found that autism was twice as common in babies who weren’t born head-first and 68 percent more common in those born to mothers older than age 34.
Earlier studies have suggested that factors such as genetic mutations, parental age and low-birth weight may explain the increase in autism diagnoses in the U.S. The new analysis bolsters these suggestions with epidemiologic data from the U.S. Centers for Disease Control and Prevention and a broad definition of what counts as an autism-spectrum disorder.
The new research “just helps validate those findings”, said Deborah Bilder, one of the authors, in a telephone interview April 24. “There wasn’t a finding that hadn’t been seen in some or more papers in the past,” said Bilder, an assistant professor of psychiatry at the Utah School of Medicine.
The study was released by the journal Pediatrics and was supported by the Atlanta-based CDC and the Utah Department of Health.
Autism is usually diagnosed in early childhood. Symptoms can vary and include difficulty with communication or social interaction and repetitive behaviours.
Eleven of the 132 children with autism in the study were born in the breech position, compared with 565 of the 13,200 children without the disorder. Eighteen children with autism had mothers older than age 34, compared with 1,209 children in the control group.
The disorder has been designated a priority research area by the National Institutes of Health as the agency dispenses grants using the $10.4 billion in stimulus funding it received this year, Acting NIH Director Raynard Kington said in March 26 testimony to Congress.
The CDC reported in 2007 that about 1 in 150 8-year-old children in the U.S. have an autism-spectrum disorder, more than 10 times some previous estimates that didn’t take into account the full range of symptoms. The agency now estimates that as many as 560,000 Americans age 21 and younger have an autism-spectrum disorder.
The institutes committed $60 million to address the differences across the autism spectrum of disorders. Researchers will be asked to help develop and test diagnostic screening tools, assess risk from exposures and adapt existing pediatric interventions for children diagnosed with the condition.