In The Politics of Autism, I discuss various ideas about what causes the condition.
Here is just a partial list of correlates, risk factors, and possible causes that have been the subject of serious peer-reviewed studies:
• Air pollution and proximity to freeways;
• Maternal thyroid issues;
• Autoimmune disorders;
• Induced labor;
• Preterm birth;
• Birth by cesarean section;
• Maternal and paternal obesity;
• Maternal and paternal age;
• Maternal post-traumatic stress disorder;
• Smoking during pregnancy;
• Antidepressant use during pregnancy.
Lisa Rapaport reports at Scientific American:
Mothers who are obese during pregnancy have almost twice the odds of having a child with autism as women who weigh less, a U.S. study suggests.
When women are both obese and have diabetes, the autism risk for their child is at least quadrupled, researchers reported online January 29 in Pediatrics.
"In terms of absolute risk, compared to common pediatric diseases such as obesity and asthma, the rate of autism spectrum disorder (ASD) in the U.S. population is relatively low, however, the personal, family and societal impact of ASD is enormous," said senior study author Dr. Xiaobin Wang, a public health and pediatrics researcher at Johns Hopkins University in Baltimore.A release from Drexel University:
By comparing birth records over a period of nine years, Drexel researchers found that the children of mothers who took a certain asthma medication during pregnancy faced an elevated risk of being diagnosed with autism spectrum disorder.
"Since the teratogenic [an agent which could cause development issues in a fetus] potential of most drugs with respect to neurodevelopmental outcomes is generally understudied, I would hope my research would encourage more researchers to explore prescription drug use as a potential autism spectrum disorder risk factor," said Nicole Gidaya, PhD, a doctoral alum of Drexel's Dornsife School of Public Health and the lead author of the study.
Looking at birth records from Denmark dating between 1997 and 2007, it was determined that children whose mothers took ß-2-andrenergic receptor (B2AR) agonist drugs during pregnancy were 30 percent more likely to be eventually diagnosed with autism spectrum disorder.
The study, "In Utero Exposure to ß-2-Andregenic Receptor Agonist Drugs and Risk for Autism Spectrum Disorders," was published in the February issue of Pediatrics.A release from MIT:
In 2010, a large study in Denmark found that women who suffered an infection severe enough to require hospitalization while pregnant were much more likely to have a child with autism (even though the overall risk of delivering a child with autism remained low).
Now research from MIT, the University of Massachusetts Medical School, the University of Colorado, and New York University Langone Medical Center reveals a possible mechanism for how this occurs. In a study of mice, the researchers found that immune cells activated in the mother during severe inflammation produce an immune effector molecule called IL-17 that appears to interfere with brain development.
The researchers also found that blocking this signal could restore normal behavior and brain structure.
“In the mice, we could treat the mother with antibodies that block IL-17 after inflammation had set in, and that could ameliorate some of the behavioral symptoms that were observed in the offspring. However, we don’t know yet how much of that could be translated into humans,” says Gloria Choi, an assistant professor of brain and cognitive sciences, a member of MIT’s McGovern Institute for Brain Research, and the lead author of the study, which appears in the Jan. 28 online edition of Science.