Antidepressants During Pregnancy Increase the Risk of Autism

According to a new study, women who take a certain class of widely used antidepressants during their 2nd and 3rd trimesters of pregnancy may face almost twice the risk of having a child with autism spectrum disorder.

The new research was published last Monday December 14, 2015 in JAMA (Journal of the American Medical Association) Pediatrics. They studied 145,456 kids in Quebec that were born between 1998 and 2009, to determine if children of mothers who took antidepressants while pregnant were at an increased risk of developing an autism disorder. This is among the strongest findings linking antidepressant use in pregnancy to poor outcomes in the children born of those pregnancies.

Researchers found that the children of mothers who took antidepressants later in pregnancy were at an 87% higher risk to develop autism than those without exposure. Of the 2,532 children who fell into this category, 31 were diagnosed with autism (1.2%). Second and third trimester are a crucial time for brain development in the fetus.

The risk was even higher for children of mothers who are taking the most common form of antidepressants, called selective serotonin reuptake inhibitors (SSRIs). They had a 117% greater chance of developing an autism disorder. Outh of the 1,583 children in this category, 22 were diagnosed with autism (about 1.4%).


"Our study has established that taking antidepressants during the second or third trimester of pregnancy almost doubles the risk that the child will be diagnosed with autism by age seven, especially if the mother takes selective serotonin re-uptake inhibitors, often known by its acronym SSRIs," according to the lead researcher Anick Berard, an expert on pharmaceutical safety during pregnancy at the University of Montreal.

SSRIs are the most commonly prescribed anti-depressants, and include brand names such as Prozac, Paxil and Zoloft.

As many as one in 45 children are diagnosed with autism spectrum disorder in the United States, according to a recent study by the US Centers for Disease Control and Prevention.

Scientists still do not fully understand what causes autism, though both genetics and environment are believed to play a role.

Researchers said their findings are significant because as many as 10% of pregnant women are currently being treated with antidepressants. However, experts also stressed that no pregnant woman currently on antidepressants should stop treatment without talking to her physician first. They also said that pregnant women who are untreated for depression faced other risk factors in their pregnancy.

Dr. Max Wiznitzer, a pediatric neurologist at University Hospitals Rainbow Babies & Children's Hospital, said pregnant women on SSRIs should not stop taking their medication without more study and information.

"The absolute risk is still low and the odds are overwhelmingly in their favor that it’s low," Wiznitzer said of the chance of a child developing autism after his or her mother took an SSRI.