A Columbia University study released on Wednesday said women who had infections early in pregnancy may be twice likely to have a child with autism.
"We believe the mother's immune response to HSV-2 (herpes simplex type 2) could be disrupting fetal central nervous system development, raising risk for autism," said the research team leader Milada Mahic to NBC News.
For instance, the Zika virus can infect a developing baby's brain and some viruses may cause severe birth defects, including brain damage, according to the research.
The research was published in the journal mSphere, a U.S. journal that makes fundamental contributions to microbial sciences.
However, some experts drew a different conclusion. Ian Lipkin, an infectious disease expert at Columbia University oversaw the research and believes that it's actually the mother's immune response that causes the damage.
The chemicals made by inflammation cross the placenta and directly affect the developing brain of the fetus, Lipkin said.
Autism refers to a broad range of symptoms, including relatively mild social awkwardness of Asperger's syndrome, profound mental retardation which debilitates repetitive behaviors and an inability to communicate.