Foetal infections up risk of depression, autism in later life
A mother contracting an infection while pregnant may raise the risk of autism and depression during the child’s life, but not bipolar disorder and psychosis, according to a recent study.
“The effect of infection during pregnancy on the foetal brain and risk for subsequent development of neuropsychiatric disorders is understudied,” said researchers. “In the Swedish population, we found compelling evidence that foetal exposure to infection when the mother was hospitalized increased the risk for the child of hospital admission with autism during childhood and adulthood.”
Following 1,791,520 Swedish-born children from birth up to 41 years of age, researchers estimated the risk of developing psychopathologic conditions associated with foetal exposure to infections. Unadjusted cumulative hazard curves showed that hospital admission for autism and depression were more likely to occur by age 7 and 21 years, respectively, in those who had been exposed to infections in the womb. [JAMA Psychiatry 2019;76:594-602]
No such trends were observed for child hospitalization for bipolar disorder and psychosis.
Moreover, the type of maternal infection seemed to have little role in the associated risk of offspring psychopathologic conditions. Severe infections (sepsis, pneumonia, meningitis, pyelonephritis, encephalitis, chorioamnionitis or influenza) did not significantly increase the risk of depression and autism as compared with urinary tract infections (UTI).
Cox proportional hazards regression analysis further confirmed the principal findings. Exposure to foetal infections increased the likelihood of being diagnosed with autism by 79 percent (hazard ratio [HR], 1.79, 95 percent CI, 1.34–2.40). Likewise, there was a 24-percent rise in the risk of being diagnosed with depression in these participants (HR, 1.24, 1.08–1.42).
The same analysis verified the lack of interaction between foetal infection and bipolar disorder (HR, 0.99, 0.71–1.38) and psychosis (HR, 1.14, 0.83–1.57) risks. Adjusting for maternal mental health did not meaningfully alter findings.
The type of infection also continued to be unrelated to the effect exerted on the risk of psychopathology. Severe infections (HR, 1.89, 1.23–2.90) and UTIs (HR, 1.81, 1.18–2.78), for instance, yielded comparable risk estimates.
“Bias analyses revealed that autism results were robust to adjustment for a moderate unknown confounder, but that the depression results were vulnerable to bias from our inability to capture diagnoses among those who were never admitted to the hospital after birth,” researchers noted.
Regardless, the present findings suggest that there seems to be a foetal origin to some psychopathological conditions, they continued.
“Our findings amplify the urgency to better understand the role of maternal infection during pregnancy on foetal brain development,” researchers added. The results also “suggest that prevention of infection or anti-inflammatory therapies may be important strategies for the primary prevention of some portion of autism and depression.”