Santa Clara, CA: Evidence from a new study provides the strongest evidence to date that the use of an antidepressant like Prozac (fluoxetine), Paxil (paroxetine) or Zoloft (sertraline) during the final two trimesters of pregnancy, may be linked to a higher risk of autism spectrum disorder for the newborn.
Prozac, Paxil and Zoloft belong to a class of medications known as selective serotonin reuptake inhibitors (SSRIs), which are the most commonly prescribed type of antidepressant on the market today. According to the study, published in The Journal of the American Medical Association (JAMA) Pediatrics, the researchers analyzed health records from the Province of Quebec in Canada, from January 1999 to December 2009. During that period, some 145,456 full-term singleton infants were born, and 1,054 or 0.72 percent were subsequently diagnosed with autism.
The data showed the average age at first diagnosis was 4.6 years and the average age of children at the end of follow-up was 6.2 years. Boys with autism outnumbered girls 4 to 1. Further findings indicate that 4,724 infants (3.2 percent) were exposed to antidepressants in utero, with 4,200 exposed during the first trimester; 2,532 during the second and/or third trimester. Children in the first group diagnosed with autism numbered 40, while 31 were diagnosed in the latter group.
The researchers, led by Anick Bérard, of the University of Montreal, wrote in their article that when taking into account maternal depression as a factor, that translates to no association for use of antidepressants in the first trimester but an 87percent increased risk when used in the second or third trimester.
The researchers said that there may be several mechanisms at work that explain the phenomenon and it has to do with how serotonin impacts brain development. Scientists believe that the capacity of the brain to synthesize serotonin develops atypically in children with autism.
Prescribing antidepressants to pregnant women has long been controversial among doctors, due in part to existing data which show an increased risk for spontaneous abortion, prematurity and other physical issues. The US Food and Drug Administration has warned that one drug, Paxil, may increase the risk of birth defects.