Antidepressants in Pregnancy Not Linked to Autism
Large study finds little connection between mother's use of drugs like Prozac and children's autism risk
In theory, she noted, depression or other mental health disorders could contribute to autism risk because those moms may be more likely to make unhealthy lifestyle choices, such as smoking or drinking.
In this study, Hviid's team did initially see a slightly increased risk of autism among children whose mothers used SSRIs during pregnancy. But once the researchers factored in the psychiatric disorders themselves, that statistical link fell away.
On top of that, there was a slight increase in autism risk among children whose mothers had used an SSRI in the two years before pregnancy, but not during pregnancy.
Hviid said that all suggests it's the underlying conditions, rather than the drugs, that are associated with a small autism risk -- though the reasons, he added, are unknown.
The study, which was funded by the Danish government, is based on records from Denmark's national system of health databases. Of nearly 627,000 children born between 1996 and 2005, just under 3,900 were later diagnosed with autism.
Among those children, 52 were born to mothers who filled an SSRI prescription during pregnancy. There were just over 6,000 other children whose mothers used the antidepressants during pregnancy but did not develop autism.
Both Hviid and Chambers said the findings do not prove that SSRIs carry no autism risk. And a connection is biologically plausible, Hviid said.
No one knows what causes autism, which affects an estimated one in 88 children. But it involves a disruption in fetal brain development. It's thought that serotonin -- the chemical that SSRIs target -- contributes to early brain development, and in animals, altered serotonin levels can affect brain function and behavior.
"It's still worthwhile to continue to study this," Chambers said.
But, she added, based on the human studies so far, "if there is any increased risk of autism, it appears small."
And for any one woman, Chambers said, that possible risk would have to be balanced against the risks of leaving major depression untreated.
"For some women, the optimal situation may be to take an SSRI, even if there is an association [with autism]," Chambers said.
Hviid agreed, saying that's a decision that has to be left up to women and their health care provider.