TABLE 1—
Baseline Characteristics of Participants in the Aberdeen Children of the 1950s Cohort
| Characteristic | Sample (n = 12 150) |
| Female, no. (%) | 5 868 (48.3) |
| Father’s occupational social class category at birth, no. (%) | |
| I/II | 1 163 (9.6) |
| III nonmanual | 1 335 (11.0) |
| III manual | 5 319 (43.8) |
| IV | 1 689 (13.9) |
| V | 1 963 (16.2) |
| Unemployed/unknown/disabled/dead | 681 (5.6) |
| Mother’s no. of previous pregnancies, no. (%) | |
| 1 | 3 991 (32.8) |
| 2 | 3 505 (28.9) |
| 3 | 2 202 (18.1) |
| 4 | 1 208 (9.9) |
| ≥ 5 | 1 243 (10.2) |
| Missing | 1 (< 1.0) |
| Maternal height, cm, no. (%) | |
| ≤ 152 | 3 101 (25.5) |
| 155 | 1 911 (15.7) |
| 157 | 2 169 (17.9) |
| 160 | 1 777 (14.6) |
| 162 | 1 489 (12.3) |
| ≥ 165 | 1 703 (14.0) |
| Maternal age at birth, y, no. (%) | |
| 15–19 | 567 (4.6) |
| 20–24 | 3 798 (31.3) |
| 25–29 | 3 777 (31.1) |
| 30–34 | 2 546 (21.0) |
| 35–39 | 1 108 (9.1) |
| ≥ 40 | 354 (2.9) |
| Birth outside marriage, no. (%) | 555 (4.6) |
| Gestational age, wk, no. (%) | |
| < 37 | 760 (7.0) |
| 37–40 | 7 806 (71.7) |
| > 40 | 2 323 (21.3) |
| Missing | 1 262 (10.0) |
| Birthweight | |
| No. with data | 12 128 |
| Mean, kg (SD) | 3.3 (0.5) |
| Height at primary school entry | |
| No. with data | 11 719 |
| Mean, cm (SD) | 108.7 (10.4) |
| Weight at primary school entry | |
| No. with data | 11 639 |
| Mean, kg (SD) | 18.9 (2.9) |
| Educational attainment, no. (%) | |
| No formal qualifications | 1 624 (22.9) |
| School leaving certificate | 173 (2.4) |
| Certificate of secondary education | 165 (2.3) |
| Ordinary-level qualifications | 1 684 (23.8) |
| Advanced-level qualifications | 926 (13.1) |
| Higher national certificate | 1 138 (16.1) |
| University degree | 1 374 (19.4) |
| Missing | 5 067 (41.7) |