| HFAI (n = 97) | BiB (n = 13199) | BiB1000 (n = 1707) | |||
---|---|---|---|---|---|---|
 | n | % | n | % | n | % |
Maternal age | ||||||
  < 25 | 20 | 21.1 | 4678 | 35.4 | 612 | 35.9 |
 25–29 | 36 | 37.9 | 4275 | 32.4 | 562 | 32.9 |
 30–34 | 17 | 17.9 | 2749 | 20.8 | 325 | 19.0 |
  ≥ 35 | 22 | 23.2 | 1497 | 11.3 | 208 | 12.2 |
 Missing | 2 | 2.0 | - | - | - | - |
Maternal ethnicity | ||||||
 White British | 46 | 47.4 | 4307 | 32.63 | 652 | 38.2 |
 Pakistani | 41 | 42.3 | 4938 | 44.9 | 808 | 47.3 |
 Other | 10 | 10.3 | 1643 | 12.5 | 247 | 14.5 |
 Missing | - | - | 2311 | 17.5 | - | - |
Maternal education a | ||||||
 None | 13 | 13.7 | 2356 | 17.9 | 375 | 22.0 |
 School | 33 | 34.7 | 3361 | 25.5 | 556 | 32.6 |
 Further | 10 | 10.5 | 1563 | 11.8 | 233 | 13.7 |
 Higher | 30 | 31.6 | 2772 | 21.0 | 404 | 23.7 |
 Other/unknown | 9 | 9.5 | 828 | 6.3 | 133 | 7.8 |
 Missing | 2 | 2.0 | 2319 | 17.6 | 6 | 0.4 |
Maternal marital status | ||||||
 Married | 72 | 75.8 | 7442 | 56.4 | 1194 | 69.9 |
 Divorced | 1 | 1.1 | 230 | 1.7 | 27 | 1.6 |
 Single | 22 | 23.2 | 3227 | 24.5 | 484 | 28.4 |
 Missing | 2 | 2.0 | 2300 | 17.4 | 2 | 0.1 |
Number of persons in household | ||||||
 1 | 2 | 2.1 | 220 | 1.7 | 27 | 1.6 |
 2 | 21 | 22.1 | 2506 | 19.0 | 384 | 22.5 |
 3 | 25 | 26.3 | 2659 | 20.2 | 413 | 24.2 |
 4 | 20 | 21.1 | 1928 | 14.6 | 287 | 16.8 |
  ≥ 5 | 27 | 28.4 | 3584 | 27.2 | 594 | 34.8 |
 Missing | 2 | 2.1 | 2302 | 17.4 | 2 | 0.1 |
Maternal BMIa (Mean, SD) | 26.4 | 5.9 | 26.0 | 5.7 | 25.9 | 5.7 |