Overview
- MRI scans of 127 women from before conception through six months postpartum found an average near‑5% drop in gray matter during pregnancy, concentrated in regions for social cognition.
- Gray matter recovered only partially by six months after birth, with greater rebound linked to stronger attachment and fewer hostile feelings toward the infant.
- Rising oestrogen levels closely tracked the structural reductions, indicating a hormonal role in the neuroanatomical changes.
- The reductions were widespread, affecting about 94% of brain regions, in comparisons with non‑expectant controls recruited in Madrid and Barcelona.
- The peer‑reviewed results in Nature Communications outline time windows that could guide maternal mental‑health support, and the study did not directly test cognitive performance.