Table 1.
Characteristics of the study population (n = 400)1
| Maternal age (y) | 24.2 ± 4.32 |
| Race [n (%)] | |
| White | 114 (28.5) |
| Black | 286 (71.5) |
| Parity [n (%)] | |
| 1 | 265 (66.3) |
| 2 | 135 (33.8) |
| Highest grade completed [n (%)]3 | |
| ≤8 | 15 (3.9) |
| 9–11 | 120 (31.1) |
| 12 | 136 (35.2) |
| 13–15 | 108 (28.0) |
| ≥16 | 9 (2.3) |
| Household income below 1986 poverty level [n (%)]4 | 243 (70.0) |
| Maternal raw PPVT-R score | 129 ± 15 |
| Home Screening Questionnaire score | 36.5 ± 6.4 |
| Infant characteristics | |
| Gestational age (wk) | 38.2 ± 2.6 |
| Birth weight (g) | 3028 ± 643 |
| Male [n (%)] | 211 (52.8) |
| SGA [n (%)] | 40 (10) |
| Head circumference (cm) | 33.5 ± 2.1 |
| Child WPPSI-R scores | |
| Full Scale IQ | 82.4 ± 12.1 (45–118)5 |
| Verbal IQ | 84.0 ± 11.9 (27–116) |
| Performance IQ | 84.4 ± 13.3 (49–130) |
| Information subscale | 6.6 ± 2.7 (1–16) |
| Block Design subscale | 6.8 ± 2.5 (1–15) |
1
PPVT-R, Peabody Picture Vocabulary Test–Revised; SGA, small for gestational age; WPPSI-R, Wechsler Preschool and Primary Scale of Intelligence–Revised; IQ, intelligence quotient.
2
x¯ ± SD (all such values).
3
n = 386.
4
n = 347.
5
x¯ ± SD; range in parentheses (all such values).