Table I.

Baseline characteristics.

Variable	Caucasians					African Americans
	Term labor (n = 100), median [range]a		Preterm labor (n = 105), median [range]a		P-valueb	Term labor (n = 91), median [range]a		Preterm labor (n = 41), median [range]a		P-valueb
Maternal age (years)	28 [18–40]		28 [18–40]		0.309	24 [18–38]		25 [18–38]		0.474
Gestation age (weeks)	39 [37–42]		34 [24–36]		<0.001	39 [37–41]		34 [23–36]		<0.001
Birth weight (g)	3352 [2134–4252]		2151 [370–3790]		<0.001	3255 [2075–4382]		2267 [746–3685]		<0.001
APGAR 1	9 [4–9]		8 [1–9]		<0.001	8 [2–9]		8 [1–9]		0.012
APGAR 5	9 [8–10]		9 [1–9]		<0.001	9 [7–10]		9 [6–9]		<0.001
Smoking (Count Y, yes; N, no)	18Y	80N	25Y	71N	0.198	13Y	77N	10Y	31N	0.165

^aRange-upper and lower range of the data; ^bP-value compares preterm labor to term labor. Non-parametric Mann–Whitney two-sample rank-sum tests were used if data was not normally distributed.