07/27/2026
Pregnancy reduces grey matter in the cortex, concentrated in the default mode network, the system tied to self-reflection and social processing. Researchers read this as reorganization rather than damage: the pattern resembles adolescence, and women with the largest reductions showed the strongest attachment scores. A February 2026 study found a second pregnancy doesn’t repeat the first, shifting instead toward attention and sensorimotor networks. The idea that this preps you for two kids is the authors’ speculation, not a tested finding.
Source: Straathof et al., Nature Communications, Feb 2026. Pregnancy Brain Lab, Amsterdam UMC.