Table 1.

Participant characteristics. The last column reports the p values of the group differences computed with the Wilcoxon rank-sum test for continuous variables and with the chi-squared test for categorical variables.

	preterm (N=59)	term (N=46)	all (N=105)	preterm vs. term
PMA at birth (weeks)	23.42-32.00	37.00–42.00	23.42-42.00	$p=1.88\times {10}^{-18}$
Birth weight (grams)	454–2100	2556–4560	454–4560	$p=1.93\times {10}^{-18}$
PMA at scan (weeks)	38.00–44.56	38.28–43.84	38.00–44.56	$p=.0035$
M:F ratio	29:30	26:20	55:50	$p=.4532$

PMA = Postmenstrual age, M = male, F = female.