Prenatal exposure to certain medications that are often prescribed to treat depression, anxiety, and other mental health disorders, is associated with a higher incidence of autism spectrum disorder and developmental delays in boys, new research shows.
“This study provides further evidence that in some children, prenatal exposure to SSRIs (selective serotonin reuptake inhibitors), may influence their risk for developing an autism spectrum disorder,” says Professor Irva Hertz-Picciotto, chief of the division of environmental and occupational health at University of California, Davis.
“It also highlights the challenge for women and their physicians, to balance the risks vs. benefits from taking these medications, given that a mother’s underlying mental-health conditions may also pose a risk to both herself and her child.”
The 966 mother-child pair participants included the mothers of children with autism spectrum disorder (ASD), developmental delay (DD), and those with typical development (TD). Children ranged in age from two to five. A majority of the children in each category were boys—82.5 percent of those with ASD, 65.6 percent with DD, and 85.6 percent TD.
More common among boys
While the study, published in Pediatrics, included girls, the substantially stronger effect in boys suggests a possible gender difference in the effect of prenatal SSRI exposure, the authors write.
“We found prenatal SSRI exposure was nearly three times as likely in boys with ASD relative to those with typical development, with the greatest risk occurring when exposure took place during the first trimester,” says Li-Ching Lee, psychiatric epidemiologist. “SSRIs also were elevated among boys with developmental delay, with the strongest exposure effect in the third trimester.”
According to statistics recently released by the US Centers for Disease Control and Prevention, an estimated 1 in 68 US children are diagnosed with ASD. The condition is almost five times more commonplace among boys than girls. The researchers caution that while there has been a co-occurring increase in the use SSRIs, it likely is not a significant contributor to the increase in the prevalence of autism.
“Because of low rates of SSRI use during pregnancy and possible co-existing factors influencing susceptibility to ASD from SSRI exposure, any contribution of these medications to the increase in the prevalence of ASDs likely is minimal,” Lee says.
Maternal depression carries its own risks to the fetus, so that the benefits of using SSRIs during pregnancy should be weighed carefully against any potential harm, the authors note. They also note that large sample studies are needed to investigate the effects in girls with ASD.
The study’s limitations include the difficulty of isolating SSRIs’ effects from those of their indications for use, lack of information on SSRI dosage precluding dose-response analyses, and the relatively small sample of children with developmental delay resulting in imprecise estimates of association.
Rebecca Harrington of UC Davis, Rosa Crum of Johns Hopkins University, and Andrew W. Zimmerman of Massachusetts General Hospital for Children’s Lurie Center for Autism are other study authors. Grants from the National Institute of Environmental Health Sciences, the UC Davis MIND Institute, and Autism Speaks funded the research.
Source: UC Davis