Table 2.

Increase of fetal brain volume measurements with gestational age by dates and biometry.

Measure	Increase /wk, %*		Power-law exponent*
	GA (dates)	GA (US)	BPD	HC
Supratentorial parenchyma	16.5	16.0	2.7	3.4
Ventricles	4.2	3.7	0.6	0.6
Extra-axial cerebrospinal fluid	12.6	11.9	2.2	2.8
Cerebellum: overall	15.8	15.2	2.5	3.2
axial	14.4	13.8	2.3	2.9
coronal	15.9	15.1	2.5	3.2
sagittal	17.1	16.6	2.8	3.5

^*From mixed-model analysis of variance; see Methods for details. All rates and exponents differ significantly from zero, p<0.05. All were invariant across plane of observation, p>0.10, except for cerebellum, which by all measures increased more rapidly in sagittal plane, least in axial plane (p<0.01). HC= head circumference; GA= gestational age BPD=biparietal diameter