Maternal infections associated with increased suicide risk in offspring

Maternal infections during pregnancy are associated with an increased risk of suicide attempt in the offspring later in life, according to a new large study based on Danish register data.

The study included more than 2.1 million individuals aged 10 years and older living in Denmark between 1987 and 2021. In this group, more than 32,000 individuals had a suicide attempt.

Among individuals exposed to maternal infection during pregnancy, the risk of suicide attempt was higher than for those who were not exposed. Even after accounting for other relevant factors, children who were exposed to maternal infection during pregnancy had a 46% higher risk of suicide attempt compared to those not exposed. The association was particularly pronounced for infections occurring during the second and third trimesters of pregnancy, periods that are critical for fetal brain development. It is, however, important to underscore that suicide attempts are rare, it occurs among 1-2 out of 1000 individuals.

“Maternal infections during pregnancy may influence neurodevelopment of the fetus through immune and inflammatory pathways” said Dr. Massimiliano Orri, assistant professor at McGill University, and adjunct senior researcher at the Danish Research Institute for Suicide Prevention (DRISP). “Our findings suggest that these early biological processes may have consequences for mental health that extend well into adolescence and adulthood”.

The findings underline the importance of maternal health across the life course and suggest that suicide prevention efforts may benefit from a broader perspective that includes prenatal and perinatal factors. The study was published in the journal Molecular Psychiatry