A groundbreaking study has revealed that the brains of mothers undergo significant structural changes during pregnancy, with 94% of the grey matter in the brain being affected. Conducted by a team from Universitat Autonoma de Barcelona (UAB), the research found that grey matter volume decreases by nearly 5% during pregnancy, particularly in regions associated with social cognition. Interestingly, the changes partially recover after childbirth.

This study, published in Nature Communications, is the first to use neuroimaging techniques to analyse the brains of pregnant women. It compared the brains of pregnant women with those of non-pregnant mothers whose partners were pregnant, allowing the researchers to distinguish biological changes from those influenced by the experience of motherhood.

The collaborative effort involved several esteemed institutions, including UAB, the Gregorio Maranon Health Research Institute, Hospital del Mar Research Institute, and other international partners.

Key findings from the study indicate that pregnancy induces a dynamic shift in brain structure, closely linked to hormonal fluctuations and the psychological health of mothers. The research specifically observed a 4.9% reduction in grey matter volume during the first pregnancy, particularly in brain areas involved in social cognition. This reduction was followed by a partial recovery after childbirth.

A key aspect of the study is its identification of a connection between changes in brain grey matter and estrogen levels during pregnancy. Researchers found that greater increases in estrogen levels, followed by their subsequent decline after childbirth, were associated with more substantial reductions in brain grey matter and its eventual recovery.

These insights contribute to a deeper understanding of the complex transformations that occur in the maternal brain, highlighting the interplay of biological changes, hormonal shifts, and emotional experiences during pregnancy. The research provides new perspectives on maternal brain health, offering valuable information for future studies on the neurological impacts of pregnancy.