A new study suggests a link between antidepressants taken by women during pregnancy and autism in their children, researchers report.

The findings are strong evidence that the drugs known as selective serotonin reuptake inhibitors, including the most commonly-prescribed antidepressants, such as Prozac, Zoloft or Paxil, when taken during the final two pregnancy trimesters, may be linked to an elevated risk of autism spectrum disorder in a child, they say.

SSRIs work by affecting naturally-occurring chemicals that act as messengers in the brain, and some scientists have suggested that in children with autism, the capacity of the brain to synthesize serotonin has developed atypically.

For the study appearing in JAMA Pediatrics, the researchers analyzed a Canadian registry of more than 145,000 newborns which were followed for around six years.

Included in the Quebec registry were medical records of the mothers for at least a year prior to delivery, allowing the researchers to see whether they had been prescribed SSRIs during their pregnancy.

The average risk for autism rose by 87 percent among children whose mothers had taken antidepressants during their pregnancy, the study found.

However, lead study author Anick Bérard from the University of Montreal emphasizes, autism remains a rare condition; even in the women who took antidepressants, the risk of autism rose from 0.7 percent of total births to just 1.2 percent.

The study findings should not be an occasion for panic, she says.

"This study is not to be viewed as a scary thing for mothers," Bérard says.

Rather, she says, it should be considered more information on the proper treatment of depression during pregnancy.

"We strongly believe depression is a serious condition and should be treated," she says. "But we're advocating treating depression differently, at least during pregnancy."

While use of SSRIs in pregnant women is increasing in the United States, Dr. Susan Hyman, a professor of pediatrics at the University of Rochester Medical Center, emphasizes a key finding of the study, namely that "the dramatic, overwhelming number of children exposed to SSRIs don't have autism."

On the other hand, says Hyman — who was not involved in the study — untreated depression can be bad for mother and child.

"We would not want people to feel guilty," about the use of antidepressants, she says. "That is something that is not productive."

The study's findings highlight the need for women who suffer from depression to talk to their doctors before pregnancy about possible non-drug options for treating their condition, she says.