Cohort frequencies and percentages of live singleton deliveries, age, smokers, diabetes, BMI and gestation for 2008–2013
| White British | Indian | Pakistani | Bangladeshi | Total | ||
| Live singletons N (%) | 6862 (46.1) | 1710 (24.8) | 5025 (33.8) | 2013 (13.5) | 14 871 | |
| p | <0.001 | 0.370 | <0.001 | <0.001 | ||
| Maternal age N (%) | 16–20 | 1006 (14.6) | 15 (1.5) | 217 (4.3) | 91 (4.5) | 1329 (8.9) |
| 21–25 | 1710 (24.8) | 200 (20.5) | 1486 (29.3) | 581 (28.5) | 3977 (26.5) | |
| 26–30 | 2010 (29.1) | 407 (41.7) | 1859 (36.6) | 801 (39.3) | 5077 (33.9) | |
| 31–35 | 1487 (21.5) | 261 (26.8) | 1099 (21.6 | 431 (21.2) | 3278 (21.9) | |
| 36–40 | 599 (8.7) | 79 (8.1) | 378 (7.4) | 123 (6) | 1179 (7.9) | |
| 40+ | 97 (1.4) | 13 (1.3) | 38 (0.7) | 9 (0.4) | 157 (1) | |
| p | <0.001 | <0.001 | <0.001 | <0.001 | ||
| Smokers N (%) | 1490 (21.6) | 19 (2) | 73 (1.4) | 18 (0.9) | 1600 (10.7) | |
| p | 0.001 | 0.002 | 0.031 | 0.016 | ||
| Diabetic | 54 (0.8) | 14 (1.4) | 117 (2.3) | 18 (0.9) | 253 (1.7) | |
| p | 0.11 | 0.08 | 0.54 | 0.39 | ||
| BMI N (%) | 19–24.9 | 2518 (36.5) | 424 (43.5) | 1624 (32) | 757 (37.2) | 5323 (35.5) |
| 25–29.5 | 1710 (24.6 | 262 (26.9) | 1297 (25.6) | 546 (26.8) | 3815 (25.5) | |
| 30–39.9 | 1146 (16.6) | 79 (8.1) | 794 (15.6) | 226 (11.1) | 2245 (15) | |
| 40–50 | 182 (2.6) | 8 (0.8) | 80 (1.6) | 24 (1.2) | 294 (2) | |
| p | <0.001 | 0.07 | <0.001 | <0.001 | ||
| Gestation (in weeks) N (%) | 24–37 | 451 (6.5) | 74 (7.6) | 308 (6.1) | 124 (6.1) | 957 (6.4) |
| 37+ | 6447 (93.5) | 899 (92.4) | 4757 (93.9) | 1908 (93.6) | 14 011 (93.6) | |
| p | <0.001 | <0.001 | <0.001 | <0.001 |
BMI, body mass index.