How the brain changes during pregnancy

The Background

Pregnancy leads to widespread physiological changes, including in the brain. Pregnancy is known to increase neuroplasticity and lead to reduced grey matter and cortical volume postpartum, but how this happens over the course of a pregnancy remains unclear.

In this week’s study, scientists tracked brain changes in a woman from 3 weeks preconception to 2 years postpartum and provide a detailed map of how her brain changed over time.

The Findings

The study found that the grey matter volume, cortical thickness, and overall brain volume reduced during pregnancy and partially recovered after birth (left side of the above graph). In contrast, they found that the global microstructural integrity of white matter, the lateral ventricle expansion, and the cerebrospinal fluid increased during pregnancy (right side).

Next, they zoomed in on weeks 0-36 and mapped how the grey matter in specific regions of the participant’s brain changed over time. To do this, they used precision MRI scans to track local changed in brain volume in many different brain structures. They found that the changes were not uniform across the brain and were more drastic in particular brain regions, such as the region containing the hypothalamus and the hippocampus.

Unlike the grey matter, the participant’s white matter increased in integrity throughout the pregnancy and remained increased post-birth.

Overall, this study showed the remarkable ability of a pregnant woman’s brain to remodel itself. The exact mechanism behind this remodeling and its overall effect will be the focus of future studies.

They go into a lot more detail about how specific brain regions changed over the two year study, including in the medial temporal lobe, hippocampal subfields CA1, CA2/3, and parahippocampal cortex. Check out the full study if you’re interested.

See you next week for more science,

Neil