Maternal inflammation during pregnancy may affect a child’s brain development

CRP levels within the normal range (<10 mg/L) were associated with differences in cortical thickness, surface area, and volume in the child’s brain, with effects varying between boys and girls. In boys, effects were observed in two brain regions, while in girls, changes were noted in one region. Higher CRP levels (>10 mg/L) were particularly linked to structural brain features in girls.

The study suggests that the effects of immune system activation on brain development are sex-dependent. This is an important finding, as previous research has also indicated that prenatal stressors may influence brain development and mental health risks differently in boys and girls. For instance, high CRP levels have previously been associated with an increased risk of autism spectrum disorders and schizophrenia.

“Our results show that maternal inflammation during pregnancy can have sex-specific effects on a child’s brain development, but we still do not fully understand why these differences arise or how exactly they manifest,” explains Postdoctoral Researcher Lassi Björnholm. “However, our study provides a more detailed understanding of the links between the immune system and brain development. These findings also open up new avenues to investigate how maternal immune activation might relate to the risk of neurodevelopmental or psychiatric disorders later in life.”

The study utilised extensive birth cohorts from Finland (FinnBrain, NFBC1986), the Netherlands (Generation R), and Spain (PREOBE). The structure of the children’s brains was studied when they were between 5 and 26 years old, depending on the cohort.

Research article: Niskanen A, Barron A, Azaryah H et al. Sex-specific associations between maternal prenatal inflammation and offspring cortical morphology in youth: A harmonised study across four birth cohorts. Brain, Behavior, and Immunity, Vol 123, 2025.