Table 2. Association of Gestational Age at Birth With Global Brain Volumes^a.

Model	Total brain volume		Cerebral gray matter volume		Cerebral white matter volume		Cerebellar gray matter volume		Cerebellar white matter volume		Subcortical gray matter volumeb
	Difference (95% CI)	P value	Difference (95% CI)	P value	Difference (95% CI)	P value	Difference (95% CI)	P value	Difference (95% CI)	P value	Difference (95% CI)	P value
All children
GAB, wk (n = 3079)
Model 1	6.1 (4.2 to 8.0)	<.001	3.7 (2.7 to 4.7)	<.001	1.7 (0.9 to 2.6)	<.001	0.5 (0.3 to 0.7)	<.001	0.2 (0.1 to 0.2)	<.001	0.2 (0.1 to 0.2)	<.001
Model 2	4.5 (2.7 to 6.3)	<.001c	2.8 (1.8 to 3.7)	<.001c	1.2 (0.3 to 2.0)	.006c	0.4 (0.2 to 0.5)	<.001c	0.1 (0.1 to 0.2)	<.001c	0.2 (0.1 to 0.2)	<.001c
Term children
GAB, wk (n = 2718)
Model 1	6.7 (3.6 to 9.7)	<.001	3.8 (2.2 to 5.4)	<.001	2.3 (0.9 to 3.7)	.002	0.4 (0.1 to 0.8)	NA	0.1 (0.05 to 0.2)	.003	0.1 (0.01 to 0.2)	.03
Model 2	4.8 (1.8 to 7.7)	.002c	2.8 (1.2 to 4.3)	<.001c	1.6 (0.3 to 3.0)	.02c	0.2 (−0.1 to 0.6)	NA	0.1 (0.03 to 0.2)	.01c	0.1 (0.01 to 0.2)	.03c

Abbreviations: GAB, gestational age at birth; NA, not applicable.

^a In the results of these regression models, the effect estimates represent the difference in cubic centimeters for brain volumes per 1-week-longer gestational duration. Model 1 is a minimally adjusted model corrected for child sex and age at the neuroimaging assessment. Model 2 is a fully adjusted model, corrected for child sex and age at the neuroimaging assessment, maternal ethnicity, age at intake, marital status, educational level, psychopathologic condition, smoking and alcohol use during pregnancy, and family income.

^b Intracranial volume was additionally adjusted for in both models.

^c The associations survived a false discovery rate correction for multiple testing (applied model 2 only).