Risk factor/characteristics | Data |
Antenatal/developmental factors | |
Parity | 2 (1–2) |
Pre-eclampsia, No (%) | 15 394 (8.7) |
Birth weight (g) | 3606 (491) |
Birth length (cm) | 51.1 (2.1) |
Head circumference (cm) | 34.9 (1.5) |
Intrapartum/neonatal factors | |
Maternal infection, No (%) | 2111 (1.2) |
Neonatal infection, No (%) | 314 (0.2) |
Mode of delivery, No (%) | |
Vaginal | 151 971 (86.1) |
Instrumental | 13 306 (7.5) |
Caesarean section | 11 247 (6.4) |
Season of birth, No (%) | |
Spring | 50 717 (28.7) |
Summer | 43 984 (24.9) |
Autumn | 40 636 (23.0) |
Winter | 41 187 (23.3) |
Year of birth, No (%) | |
1973 | 44 779 (25.4) |
1974 | 46 714 (26.5) |
1975 | 43 593 (24.7) |
1976 | 41 438 (23.5) |
Maternal data | |
Maternal age (years) | 26.5 (23.3–29.8) |
Maternal occupation, No (%) | |
Manual worker | 66 428 (37.6) |
Non-manual worker | 80 213 (45.4) |
Self-employed | 8170 (4.6) |
Other | 21 713 (12.3) |
Maternal education status, No (%) | |
<9 Years | 28 935 (16.4) |
9–10 Years | 35 379 (20.0) |
Full secondary | 68 253 (38.7) |
Higher education | 43 957 (24.9) |
Paternal data | |
Paternal age (years) | 28.8 (25.8–32.2) |
Paternal occupation, No (%) | |
Manual worker | 63 453 (36.0) |
Non-manual worker | 76 669 (43.4) |
Self-employed | 17 657 (10.0) |
Other | 18 745 (10.6) |
Paternal education status, No (%) | |
<9 Years | 49 120 (27.8) |
9–10 Years | 25 827 (14.6) |
Full secondary | 61 758 (35.0) |
Higher education | 39 819 (22.6) |
Data are mean (SD), median (IQR) or number (%) as appropriate.