Table 2.
Characteristics of mothers and children who participated in study: categorical variables. (Values are numbers (percentages) of participants)
| All | Boys | Girls | |
|---|---|---|---|
| Maternal education: | |||
| None, CSE, or vocational | 824 (18) | 389 (18) | 435 (18) |
| O levels | 1285 (28) | 611 (28) | 674 (28) |
| A levels | 1638 (36) | 771 (35) | 867 (36) |
| Degree | 867 (19) | 416 (19) | 451 (19) |
| Social class: | |||
| IV or V | 753 (16) | 340 (16) | 413 (17) |
| III Manual | 1187 (26) | 547 (25) | 640 (26) |
| III Non-manual | 1275 (28) | 617 (28) | 658 (27) |
| I or II | 1399 (30) | 683 (31) | 716 (30) |
| Maternal smoking during pregnancy: | |||
| No | 3752 (81) | 1777 (81) | 1975 (81) |
| Yes | 862 (19) | 410 (19) | 452 (19) |
| Maternal pre-pregnancy obesity: | |||
| No | 4381 (95) | 2074 (95) | 2307 (95) |
| Yes | 233 (5) | 113 (5) | 120 (5) |
| Child’s pubertal stage at 12 years old: | |||
| Stage 1 | 548 (21) | 388 (37) | 160 (10) |
| Stage 2 | 945 (35) | 456 (43) | 489 (30) |
| Stage 3 | 722 (27) | 162 (15) | 560 (35) |
| Stage 4* | 376 (14) | 50 (5) | 326 (20) |
| Stage 5* | 77 (3) | 77 (5) | |
| Child’s pubertal stage at 14 years old: | |||
| Stage 1 | 119 (6) | 105 (11) | 14 (1) |
| Stage 2 | 288 (14) | 197 (21) | 91 (8) |
| Stage 3 | 553 (27) | 272 (29) | 281 (25) |
| Stage 4* | 832 (40) | 358 (38) | 474 (42) |
| Stage 5* | 268 (13) | 268 (24) |
*For boys, stages 4 and 5 have been amalgamated.