Brain development unaffected by stress during late pregnancy

Stress can impact neurodevelopment of the child, even before birth. One of the ways this is hypothesized to happen is via a mother’s heightened cortisol levels during pregnancy. In the current study, researchers were unable to find evidence for this hypothesis. This recently published study examined associations between late pregnancy maternal cortisol levels and individual differences in brain structure during early adolescence – a sensitive period of social-emotional development. This collaborative study was conducted by researchers from Radboudumc, Donders Institute, Behavioural Science Institute, and Max Planck Institute for Human Development and published in ‘rontiers in Neuroscience, on August 31^st.

The study used longitudinal data from the BIBO study, led by Professor Carolina de Weerth at Radboudumc. In the third trimester of pregnancy, salivary cortisol samples were collected from a healthy community group of mothers as indicators of physiological stress. At age 12, 98 children underwent an MRI scan. The researchers were particularly interested in changes in the prefrontal cortex, amygdala, and hippocampus – regions high in glucocorticoid receptors, and therefore theoretically particularly susceptible to prenatal cortisol. A high-resolution scan of the hippocampus was also taken to investigate specific hippocampal subfields.

Using multiple indices of grey matter volume and analysis software, Anna Tyborowska showed that prenatal maternal cortisol levels were not associated with grey matter volume differences in these adolescents. These findings suggest that late pregnancy maternal cortisol may be less strongly related to structural differences in adolescence than hypothesized, at least in healthy community samples. It might be that such effects are present only in more extreme cases of prenatal stress or that mild stress effects are masked by more pronounced developmental changes occurring during early adolescence.

Publication

Tyborowska, A., Grüber, K., Beijers, R., Kühn, S., Roelofs, K., de Weerth, C. (2022). No evidence for association between late pregnancy maternal cortisol and grey matter volume in a healthy community sample of young adolescents. Frontiers in Neuroscience. https://doi.org/10.3389/fnins.2022.893847