Subjects n (%) | 781 (35.2) | 533 (24.0) | 445 (19.2) | 109 (4.9) | 371 (16.7) |
Birth weight g | 3000/3320/3575 | 3050/3325/3600 | 3000/3300/3600 | 2950/3220/3450 | 2850/3130/3400 |
SGA | 7.8 | 7.2 | 10.9 | 13.0 | 16.3 |
FwGR | 8.3 | 7.7 | 8.3 | 10.2 | 17.1 |
Birth length cm | 48.2/49.9/51 | 48.5/50/51 | 48.9/50/51 | 48.8/50/51 | 48/49/50.4 |
Birth head circumference cm | 33.5/34.5/35.5 | 33.6/34.5/35.4 | 33.5/34.5/35 | 33/34/35 | 33/34/35 |
Gestational age weeks | 38.8/39.9/40.6 | 39/39.9/40.9 | 38.8/39.9/40.7 | 38.9/39.7/40.7 | 38.7/39.7/40.6 |
Males | 51.5 | 52.5 | 49.2 | 58.7 | 53.9 |
Cotinine ≥4 ng·mL−1 | 36.0 | 48.78 | 75.1 | 100 | 100 |
Cotinine ng·mL−1+ | 5.9/9.0/15.5 | 6.7/11.4/20.2 | 9.6/17.8/28.6 | 260.7/680.6/422.8 | 988.3/1864.7/2975.7 |
Smoking before pregnancy | 37.8 | 44.3 | 52.0 | 82.6 | 100.0 |
Smoking at week 12 | 0.5 | 1.3 | 1.9 | 9.3 | 100.0 |
Mean maternal age yrs | 32.6 | 31.9 | 31.3 | 30.7 | 31.2 |
Maternal asthma | 6.5 | 7.3 | 8.5 | 7.4 | 7.6 |
Higher education | 42.9 | 47.5 | 24.2 | 24.8 | 12.7 |
Manual social class | 45.1 | 43.6 | 62.2 | 56.1 | 69.5 |
Maternal BMI pre-pregnancy | 20.8/22.5/24.9 | 20.9/22.9/25.4 | 20.3/22.2/25 | 21.3/22.9/25.8 | 20.9/23/25.9 |
Nullipara | 51.8 | 58.0 | 63.4 | 56.0 | 59.0 |