In the new study, researchers analyzed data from more than 14,500 children born in the United Kingdom during the 1990s.
The study found that people with a maternal grandmother who smoked during her pregnancy had a 53 percent increased risk of developing autism.
The findings also showed that girls whose maternal grandmother smoked during pregnancy were 67 percent more likely to have autism-linked traits -- symptoms such as poor social communication skills and repetitive behaviors.
The researchers agreed with Halladay: Exposure to cigarette smoke while in the womb could affect a female's developing eggs, causing changes that may eventually affect the development of her own children.
Still, the study authors stressed that further investigation is needed to determine what those molecular changes might be, and to find out if the same associations occur in other groups of people.
