Variable | N = 851 | Cases, n or mean | % or s.d. | N = 2257 | Controls, n or mean | % or s.d. | Chi-square or t-test (p-value) |
---|---|---|---|---|---|---|---|
Maternal age | 12.24 (0.06) | ||||||
< 20 | 846 | 33 | 3.9 | 2238 | 59 | 2.6 | |
20–24 | 115 | 13.6 | 274 | 12.2 | |||
25–29 | 228 | 27.0 | 631 | 28.2 | |||
30–34 | 265 | 31.3 | 794 | 35.5 | |||
35–39 | 160 | 18.9 | 396 | 17.7 | |||
40+ | 45 | 5.3 | 84 | 3.8 | |||
Maternal BMI | 842 | 27.7 | 6.9 | 2229 | 26.3 | 6.1 | 4.99 (< 0.0001) |
Maternal ethnicity | 21.43 (0.0015) | ||||||
White | 851 | 522 | 61.3 | 2257 | 1545 | 68.5 | |
Black | 22 | 2.6 | 42 | 1.9 | |||
South Asian | 90 | 10.6 | 219 | 9.7 | |||
South East and East Asian | 40 | 4.7 | 111 | 4.9 | |||
Maori | 46 | 5.4 | 107 | 4.7 | |||
Pacific | 91 | 10.7 | 154 | 6.8 | |||
Others | 40 | 4.7 | 79 | 3.5 | |||
Parity | 56.49 (< 0.0001) | ||||||
Nulliparous | 851 | 446 | 52.4 | 2257 | 930 | 41.2 | |
1–2 | 292 | 34.3 | 1110 | 49.2 | |||
3–4 | 87 | 10.2 | 176 | 7.8 | |||
5+ | 26 | 3.1 | 41 | 1.8 | |||
Maternal education | 39.59 (< 0.0001) | ||||||
Primary | 842 | 187 | 22.2 | 2249 | 348 | 15.5 | |
Secondary | 161 | 19.1 | 343 | 15.3 | |||
University | 328 | 39.0 | 1069 | 47.5 | |||
Post-graduate degree | 73 | 8.7 | 240 | 10.7 | |||
Non-university trading education | 93 | 11.0 | 249 | 11.1 | |||
Marital status | 22.60 (< 0.0001) | ||||||
Not in stable relationship | 847 | 92 | 10.9 | 2255 | 143 | 6.3 | |
Stable relationship | 755 | 89.1 | 2112 | 93.7 | |||
Smoking status | 39.19 (< 0.0001) | ||||||
Current smoker | 848 | 145 | 17.1 | 2247 | 205 | 9.1 | |
Non-smoker or quit smoking before end of 1st trimester | 703 | 82.9 | 2042 | 90.9 | |||
Gestational age (weeks) | 851 | 36.7 | 3.6 | 2257 | 36.3 | 3.7 | 2.64 (0.008) |
28–32 | 151 | 17.7 | 479 | 21.2 | 5.78 (0.06) | ||
33–36 | 214 | 25.2 | 523 | 23.2 | |||
37+ | 486 | 57.1 | 1255 | 55.6 |