Study Says Prenatal Infection Raises Autism Risk
A study of 2 million Swedish people found that having a serious infection while pregnant raises a woman's risk of having a child with autism from 1 percent to a risk of 1.3 percent.1
The research, which was published last month in the journal Brain, Behavior, and Immunity, is the largest one so far looking at the effect of prenatal infections on autism risk. Scientists are interested in the effect of "environmental" exposures, which includes conditions during pregnancy, on a person's chance of developing autism.
This study examined Swedish hospital records of people born from 1984 to 2007, including 24,414 people with autism. Women who were hospitalized with a viral, bacterial or other infection while pregnant gave birth to 903 children who would later be diagnosed with autism, and also to 61,642 children who did not develop autism. The presence of a prenatal infection raised the risk for autism with intellectual disability. It also did not seem to matter in which trimester the infection occured, according to the study, which was conducted by American and Swedish scientists.