Table 2.

Sample Demographic Characteristics

Characteristic	N	%
Child Birth Weight (Mean ± SD)	3524.0 ± 466.4
Infant Gender
Male	1081	(50.4)
Female	1063	(49.6)
Gestational Duration (Mean ± SD)	40.2 ± 2.1
< 37 weeks	97	(4.5)
37-41 weeks	1633	(76.2)
> 41 weeks	395	(18.4)
Missing	19	(0.9)
Birth Order
1	827	(38.6)
2	766	(35.7)
3+	520	(24.3)
Missing	31	(1.4)
Year of Birth
1969-1973	248	(11.6)
1974-1978	695	(32.4)
1979-1983	1201	(56.0)
Adequate Prenatal Care
Yes	1546	(72.1)
No	212	(9.9)
Missing	386	(18.0)
Inadequate Weight Gain
Yes	179	(8.3)
No	1858	(86.7)
Missing	107	(5.0)
Maternal Age (Mean ± SD)	27.5 ± 4.5
Maternal Race
White	2062	(96.2)
Non-White	82	(3.8)
History of Diabetes
Yes	66	(3.1)
No	2027	(94.5)
Missing	51	(2.4)
History of Hypertension
Yes	159	(7.4)
No	1930	(90.0)
Missing	55	(2.6)
Cervical Incompetence
Yes	42	(2.0)
No	2073	(96.6)
Missing	29	(1.4)
Prior Low Birth Weight Infant
Yes	94	(4.4)
No	2008	(93.7)
Missing	42	(2.0)
Prior Preterm Infant
Yes	128	(6.0)
No	1963	(97.5)
Missing	53	(2.5)
Mother Smoked During Pregnancy
None	1526	(71.2)
Average 1-10 cigarettes per day	289	(13.5)
Average 11-20 cigarettes per day	206	(9.6)
Average 20 + cigarettes per day	83	(3.9)
Missing	40	(1.9)
Mother Consumed Alcohol During Pregnancy
None	1256	(58.6)
During 1-2 trimesters	209	(9.8)
During 3 trimesters	615	(28.7)
Missing	64	(3.0)
Maternal Education
< HS Education	78	(3.6)
HS Graduate	763	(35.6)
Some College	1302	(60.7)
Missing	1	(0.0)
Paternal Occupation
White collar	1054	(49.2)
Blue collar	694	(32.4)
Service occupations	359	(16.7)
Missing	37	(1.7)