Back here at home, a new headline, discussed around the kitchen table tonight about autism. We know that 1 in 88 children are diagnosed with the disorder, and this new study suggests that about a flu,... See More
Back here at home, a new headline, discussed around the kitchen table tonight about autism. We know that 1 in 88 children are diagnosed with the disorder, and this new study suggests that about a flu, during a pregnancy, can increase a child's risk. Abc's chief medical editor dr. Richard besser here with the whole picture. So many pregnant couples are going to be in fear. What do you want to say to them s snr. Reporter: The study found that moms that remembered having the flu during pregnancy, the risk of having an autistic child doubled, from 1% to 2%. Still very, very small. And this type of study is called exploratory. Doesn't prove anything but says we have to look at it further. Let's look at the other risk factors, where does this rank with them? You know, it's along the same level. We have some clues. Genetic factors are important. We know that autism runs in families. More common in boys. Parents age matters, as fathers in particular get older and hit 40, the risk goes up. And then spacing between pregnancies. If you have children closer than ever three years, the risk goes up, too. Lots of clues, no hard answers. You want to reassure everybody tonight about that 2% and the 98%? Reporter: That's right. Very small number. Women who had the flu during pregnancy don't need to worry about this. They should get a flu shot, though, if they are pregnant buzz they are at great risk for the flu.
This transcript has been automatically generated and may not be 100% accurate.