Children who are born with fetal inflammatory response syndrome are at an increased risk for psychiatric disorders including autism spectrum disorder, attention-deficit/hyperactivity disorder (ADHD), and conduct disorder, according to a studypublished yesterday in Translational Psychiatry.
Fetal inflammatory response syndrome (FIRS) results from excess activation of the developing fetus’ immune system (caused by infection, damage to the placenta, or other stresses), leading to inflammation of the placenta.
“These results suggest that inflammation of the placenta has a critical role in the pathogenesis of neuropsychiatric disorders during childhood, independent of many potential confounders,” wrote Blake Gibson, M.D., of the University of Pittsburgh School of Medicine and colleagues.
Gibson and colleagues analyzed electronic health record data from a women’s hospital at the University of Pittsburgh Medical Center. They looked specifically at children who were born between January 1, 1999, and April 1, 2018, and met criteria for FIRS. They also randomly selected a subset of children born during the same period for the control group. The control group had either normal placenta reports or no placenta reports at all. (Placentas are not routinely examined after delivery unless there are suspected abnormalities or the newborn has poor health.)
Participants were required to have at least five years of electronic health record follow-up data to enable researchers to capture information about the onset of a psychiatric disorder in the children. Additionally, the researchers examined the mothers’ history of psychiatric disorders and substance use.
A total of 4,861 children with FIRS were included, as well as 31,927 children in the control group. Children born with FIRS were about 20% more likely to be diagnosed with any psychiatric disorder compared with children without FIRS during the follow-up period (average length 7.5 years); this association was significant even after controlling for maternal history of psychiatric disorders, maternal substance use during pregnancy, and maternal lifetime history of suicide attempts. Regarding individual disorders, a significant association was found between FIRS and risk of ADHD, autism spectrum disorder, conduct disorders, and posttraumatic stress disorder.
There was no difference in the mothers’ history of psychiatric disorders among children with and without FIRS, but those with FIRS were significantly more likely to have been exposed to any substance—especially alcohol, cannabis, and nicotine—in utero.
Children who meet criteria for FIRS “should be monitored closely for early identification and treatment,” the authors concluded. “Future studies are needed to identify the biological mechanisms through which inflammation in general and FIRS [specifically] increases risk for neuropsychiatric disorders.”
For related information see the American Journal of Psychiatry article “Guilt by Association: Inflammation and Shared Genetic Risk Between Stress-Related and Immune Disorders”.