Table 1.
Characteristics of 18,751 offspring1 in the Child Health and Development Studies, 1959 – 1967
| Male (n=9,582) |
Female (n=9,169) |
Total (n=18,751) |
|
|---|---|---|---|
| n (%) | n (%) | n (%) | |
| Offspring characteristics | |||
| Year of birth | |||
| 1959–61 | 2887 (30.1) | 2716 (29.6) | 5603 (29.9) |
| 1962–64 | 4636 (48.4) | 4409 (48.1) | 9045 (48.2) |
| 1965–67 | 2059 (21.5) | 2044 (22.3) | 4103 (21.9) |
| Race/ethnicity | |||
| Non-Hispanic White | 6266 (66.4) | 5999 (66.4) | 12265 (66.4) |
| Non-Hispanic Black | 2224 (23.6) | 2108 (23.3) | 4332 (23.5) |
| Hispanic | 305 (3.2) | 308 (3.4) | 613 (3.3) |
| Asian | 375 (4.0) | 344 (3.8) | 719 (3.9) |
| Other | 262 (2.8) | 281 (3.1) | 543 (2.9) |
| Missing | 150 | 129 | 279 |
| Gestational age | |||
| < 37 weeks | 794 (8.4) | 666 (7.4) | 1460 7.9 |
| ≥ 37 weeks | 8622 (91.6) | 8371 (92.6) | 16993 92.1 |
| Missing | 166 | 132 | 298 |
| Maternal characteristics 2 | |||
| Maternal age at pregnancy (years) | |||
| < 20 | 830 (8.8) | 847 (9.3) | 1677 (9.0) |
| 20–24 | 2863 (30.2) | 2785 (30.7) | 5648 (30.4) |
| 25–29 | 2748 (29.0) | 2632 (29.0) | 5380 (29.0) |
| 30–34 | 1721 (18.1) | 1595 (17.6) | 3316 (17.9) |
| 35–39 | 1003 (10.6) | 921 (10.1) | 1924 (10.4) |
| ≥ 40 | 326 (3.4) | 306 (3.4) | 632 (3.4) |
| Missing | 91 | 83 | 174 |
| Parity | |||
| Primiparous | 2940 (30.9) | 2825 (31.0) | 5765 (31.0) |
| Multiparous | 6567 (69.1) | 6285 (69.0) | 12852 (69.0) |
| Missing | 75 | 59 | 134 |
| Maternal education | |||
| Less than high school | 1458 (17.9) | 1441 (18.4) | 2899 (18.1) |
| High school or trade school | 3132 (38.4) | 3071 (39.1) | 6203 (38.8) |
| Some college or college degree | 3558 (43.7) | 3335 (42.5) | 6893 (43.1) |
| Missing | 1434 | 1322 | 2756 |
| Annual family income3 | |||
| ≤ median | 3460 (51.4) | 3433 (52.8) | 6893 (52.1) |
| > median | 3267 (48.6) | 3063 (47.2) | 6330 (47.9) |
| Missing | 2855 | 2673 | 5528 |
1
Live births excluding neonatal deaths among 14,507 women
2
Because mothers may have had more than one live birth during the study period, maternal characteristics are reported at the level of offspring
3
Median income adjusted to 1960 dollars = $6,303