Maternal infection increases risk for offspring autism and depression
A study done in Sweden suggests that foetal exposure to maternal infections may increase the risk of autism and depression in the offspring.
The findings were reported from a Swedish population-based birth registry study done between January 1973 and December 2014, which included a total of 1,791,520 children (48.6 percent females and 51.4 percent males) diagnosed with autism, depression, bipolar disorder or psychosis whose mothers were hospitalized during pregnancy with any maternal infection, severe maternal infection or urinary tract infection (UTI). [JAMA Psychiatry 2019, doi: 10.1001/jamapsychiatry.2019.0029]
Results showed that foetal exposure to any maternal infection increased the risk of an inpatient diagnosis in the child for autism (hazard ratio [HR], 1.79; 95 percent confidence interval [CI], 1.34 to 2.40) or depression (HR, 1.24; 95 percent CI, 1.08 to 1.42).
However, there was no apparent increased risk for diagnosis of bipolar disorder (HR, 0.99; 95 percent CI, 0.71 to 1.38) or psychosis including schizophrenia (HR, 1.14; 95 percent CI, 0.83 to 1.57) in childhood or adulthood after foetal exposure to maternal infection.
“The results of the study emphasize the importance of avoiding infections during pregnancy, which may impart subtle brain injuries contributing to the development of neuropsychiatric disorders,” the authors of the study said.
Further analysis showed that children or adults who were exposed to severe maternal infections (sepsis, pneumonia, pyelonephritis, meningitis or encephalitis, influenza and chorioamnionitis) during foetal life had similar magnitudes of increased risk for autism and depression compared with those exposed to maternal UTI.
The cumulative hazard for death by suicide among individuals exposed to infection during foetal life was significantly higher compared with unexposed individuals starting at age 21 years, mirroring the results from the inpatient registry for depression.
“It is possible that the findings from the study may not be generalizable to other populations since the study was restricted to Swedish women and their offspring. Likewise, since the analysis was solely derived from inpatient hospitalizations, the results of the study may not translate to infections diagnosed in the outpatient setting,” the authors commented.
Previous studies have shown that foetal exposure to infections may increase the risk of autism spectrum disorders and suggested that inflammation during gestation alters brain architecture or transcriptional programmes. A few studies of UTIs in pregnancy have also found an increased risk of developmental delay in the offspring. [Pediatrics 2008;121:758-765; Brain Behav Immun 2015;44:100-105; J Autism Dev Disord 2010;40:1423-1430; J Fam Pract 2001;50:433-437]