Women who take antidepressants during the last two trimesters of their pregnancy may be increasing their babies’ risk for autism spectrum disorder, suggests a new Canadian study. The research, published online Dec. 14 in the journal JAMA Pediatrics, found that the risk was highest if women took selective serotonin reuptake inhibitors (SSRIs) — marketed as Prozac, Zoloft and Paxil.
“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 7, especially if the mother takes … SSRIs,” co-author Anick Berard, PhD, a professor at the University of Montreal School of Pharmacy and an expert in the field of pharmaceutical safety during pregnancy, said in a news release.
Working with data collected on all pregnancies in Quebec from 1998 through 2009, Berard and her colleagues identified 145,456 full-term singleton infants. Among this group, 4,724 infants were exposed to antidepressants and 1,054 were diagnosed with autism spectrum disorder. The research team followed this group of children from conception through age 10. Study data also included information that allowed the investigators to take into account other factors associated with autism risk, including family history, mother’s depression, mother’s age at the time of pregnancy, and socioeconomic influences such as exposure to poverty.
The team defined exposure to antidepressants as the mother having filled one or more prescriptions for the drugs during the second or third trimester of pregnancy. “This period was chosen as the infant’s critical brain development occurs during this time” Berard explained.
The team used hospital records to identify which children had been diagnosed as having autism spectrum disorder. Comparing this group with children in the study who had not been exposed to antidepressants during their mothers’ pregnancies, the team found there was an 87 percent increased risk for autism among the children whose moms took an antidepressant during the final two trimesters of pregnancy. Findings showed the risk was double if SSRIs were taken, but exposure during the first trimester did not appear to increase the risk.
“It is biologically plausible that antidepressants are causing autism if used at the time of brain development in the womb, as serotonin is involved in numerous pre- and post-natal developmental processes, including cell division, migration of neuros, cell differentiation and synaptogenesis — the creation of links between the brain cells,” Berard said in the news release.
Still, experts not involved in the study point out that the overall risk of autism to a child born to a mother taking antidepressants is low, and that a woman’s untreated anxiety and depression are bad for both the mother and the child.
“It is critical to caution currently pregnant women who are on antidepressants who read about this study to not panic and suddenly discontinue their medication,” Alan Manevitz, MD, a clinical psychiatrist at Lenox Hill Hospital in New York City, told HealthDay.
“They could go through withdrawal symptoms that could be a higher risk than continuing on their medicine. They should consult their obstetrician and psychiatrist before deciding anything,” added Manevitz.