text: Pre  1st  2nd  3rd  Post 
  Stage 
  
  **Fig. 4 | White matter microstructure changes throughout the experiment.**
  **a**, Numerous white matter tracts demonstrate increasing QA in relation to 
  advancing gestation week (baseline—36 weeks, 16 scans), as determined by 
  correlational tractography analysis (FDR,*q*< 0.0001). See Supplementary 
  Table 9 for complete list of tracts with a significant correlation between QA and 
  gestation week.**b**, Summary of QA values by pregnancy stage (gestation and 
  postpartum, 23 scans) for representative ROIs significantly tied to gestation. 
  ROI-based tractometry was used to extract QA values. 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. Values were*z*scored and transformed 
  to have a mean of zero and s.d. of one for easier comparison across individual 
  tracts. AF, arcuate fasciculus; C, cingulum bundle; CC, corpus callosum; CPT, 
  corticopontine tracts; CS, corticostriatal tracts; CST, corticospinal tracts; DT, 
  dentatorubrothalamic tract; IFOF, inferior frontal occipital fasciculus; ILF, 
  inferior longitudinal fasciculus; MLF, middle longitudinal fasciculus. 