corrected at q < 0.05. Inset, right ventral diencephalon displayed the strongest 
negative association with gestation (left; baseline—36 weeks, 19 scans) and did 
not return to baseline postpartum (right; gestation and postpartum, 26 scans). 
b, The participant’s hippocampus and surrounding cortex were segmented 
into seven bilateral subregions. Quadratic (CA1, CA2/CA3) and linear regression 
analyses (PHC) revealed subfields were negatively associated with gestation 
week (baseline—36 weeks, 18 scans) and did not return to baseline postpartum 
(gestation and postpartum, 25 scans). Shaded regions in scatterplots represent 
a 95% confidence interval. Each boxplot represents IQR for each stage, with a 
horizontal line representing the median value. The whiskers indicate variability 
outside (±1.5) of this range. Outside values are >1.5× and <3× IQR beyond either 
end of the box. FDR-corrected at q < 0.05. For a and b, nonsignificant regions 
were set to zero for interpretability. See Supplementary Fig. 6 for complete 
labeling of regions in both segmentations. Brain visualizations created with R 
package ggseg48. DC, diencephalon.