Autism Update

New research reveals clues to the causes of the spectrum disorder.


The number of children diagnosed with autism, a developmental disorder that impairs social and communication skills, has been rising—about 1 percent of children in the United States have been diagnosed with it or one of the milder autism spectrum disorders (ASD). But researchers are making strides in understanding them. Here are some of the newest findings:

  • PRENATAL VITAMINS REDUCE RISK: A new study found that women who did not take a prenatal vitamin in the months before conceiving or during their first month of pregnancy were nearly twice as likely to have a child with an ASD compared with women who took a prenatal vitamin.
  • ENVIRONMENT MAY BE MORE IMPORTANT THAN GENES: A study of identical and fraternal twins found that genes were responsible for only 38 percent of the cause, and environmental factors that the twins shared in the womb were responsible for 58 percent. "Previously it was believed that environmental factors played a much smaller role," says Alycia Halladay, Ph.D., director of research for environmental sciences at Autism Speaks, a research and advocacy organization. Possible environmental risk factors include exposure to infections or medications in the womb, maternal nutrition, premature birth and advanced parental age (autism risk increases for children in mothers 35 years and older and fathers 40 years and older).
  • ANTIDEPRESSANTS MAY RAISE RISK: A new study found an increased risk of autism in children whose mothers took SSRI antidepressants like Prozac, Zoloft or CElexa during their pregnancy or in the three months before conceiving. The authors, though, reassured women that the actual risk is still quite low: 2.3 percent for children whose mothers used them during the first trimester.

A quick screening test given to babies at 12 months old can help identify those who may have an autism spectrum disorder or other developmental delays, according to a new study. The American Academy of Pediatrics currently recommends screening at 18 months and 24 months. "If you have a concern about your baby's development, discuss it with your pediatrician as soon as possible," says Halladay.