Table 1.

Characteristics of Women Selected From the Infant Growth Project for a Study of Cytokines and Small-for-Gestational-Age Birth, by Birth Status, Jefferson County, Alabama, 1985–1988

	SGA Birth (n = 75)			Not SGA Birth (n = 295)			P Valuea	Preterm Birth (n = 72)			Term Birth (n = 298)			P Valuea
	Mean (SE)	No.	%	Mean (SE)	No.	%		Mean (SE)	No.	%	Mean (SE)	No.	%
Maternal age, years	25.3 (4.6)			24.0 (4.2)			0.016	23.3 (4.3)b			24.5 (4.3)			0.047
Maternal height, cm	161.8 (6.3)			163.6 (6.5)			0.029	163.5 (5.5)			163.2 (6.7)			0.676
Prepregnancy body mass indexb	22.9 (5.7)			23.6 (5.9)			0.323	22.3 (4.6)			23.8 (6.1)			0.066
Maternal race/ethnicity							0.144							0.034
Black		59	78.7		207	70.2			59	81.9		207	69.5
White		16	21.3		88	29.8			13	18.1		91	30.5
Parity							0.455							0.144
1		52	69.3		191	64.7			42	58.3		201	67.5
2		23	30.7		104	35.3			30	41.7		97	32.5
Maternal education							0.380							0.459
Less than high school diploma		25	33.3		98	33.2			21	29.2		102	34.2
High school diploma		30	40.0		96	32.5			29	40.3		97	32.6
≥1 year of college		20	26.7		100	33.9			22	30.5		98	32.9
Missing data					1							1
Prepregnancy weight <50 kg		21	28.0		69	23.4	0.406		19	36.4		71	23.8	0.649
Cigarette smoking during pregnancy		42	56.0		117	39.7	0.011		24	33.3		135	45.3	0.066
Alcohol consumption during pregnancy		32	42.7		86	29.2	0.025		20	27.8		98	32.9	0.404
Previous infant birth weight <2,750 g		38	50.7		117	39.7	0.085		51	70.8		104	34.9	<0.001
Previous preterm birth		15	20.0		51	17.3	0.584		30	41.7		36	12.1	<0.001
Female infant		40	53.3		139	47.1	0.336		37	51.4		142	47.7	0.569

Abbreviations: SE, standard error; SGA, small-for-gestational-age.

^aP values were calculated by t statistic or chi-squared statistic and are 2-sided.

^bWeight (kg)/height (m)².