In the first study of its kind, researchers at the University of California, Santa Barbara, have looked in detail at the changes that occur in the brain from pre-conception, during pregnancy, and for two years after the birth.

The woman at the centre of the research, Dr Elizabeth Chrastil, also from the University of California, was scanned every two to three weeks using precision MRI scanners. Blood tests and hormone assays were undertaken at the same time as the scans in order to map brain changes against the hormonal changes of pregnancy. The results showed that the brain undergoes major changes during pregnancy some of which are still evident two years after the birth. Dr Chastril became pregnant through IVF, which allowed for exact timing of scans and greater accuracy of testing of hormonal levels. 

The researchers observed a decrease in grey matter volume but an increase in white matter, ventricle volume and cortical thickness; few areas of the brain appeared unaffected by the pregnancy. However, Dr Chastril said that she did not feel any difference in her cognition during pregnancy or experience so-called ‘pregnancy brain’. Prof Emily Jacobs, a researcher on the project, likened the changes to the neural ‘fine tuning’ that occurs in the brain during infancy and puberty. 

The authors recognised that this study involved only one individual. They concluded that there is much about the neurobiology of pregnancy that is not yet understand and that this is a by-product of the fact that the biomedical sciences have historically ignored women’s health.

The researchers hope that further studies will aid understanding of how brain changes may affect conditions such as perinatal depression, migraine or epilepsy for example.

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Read more: Pritschet, L. et al. (2024) Neuroanatomical changes observed over the course of a human pregnancy. Nature Neuroscience. DOI.org/10.1038/s41593-024-01741-0