Maternal age at delivery mean (SD) years | 25.5 (5.3) | 24.8 (4.9) | 0.04 | 25.1 (4.7) | 0.001 |
Maternal age categories | | | | | |
<20 | 12.2 (11.3 to 13.1) | 15.9 (11.2 to 21.7) | | 10.2 (8.7 to 11.9) | |
21–35 | 81.4 (80.3 to 82.4) | 81.1 (75.0 to 86.3) | | 86.2 (84.4 to 87.8) | |
⩾36 | 6.4 (5.8 to 7.1) | 3.0 (1.1 to 6.4) | 0.05 | 3.7 (2.8 to 4.7) | <0.001 |
Maternal smoking in pregnancy% (95% CI) | 41.1 (39.4 to 42.9) | 29.7 (23.3 to 36.9) | 0.003 | 33.0 (30.0 to 36.2) | <0.001 |
Nulliparous % (95%CI) | 38.9 (37.6 to 40.2) | 74.5 (68.0 to 80.1) | <0.001 | 60.6 (58.3 to 62.8) | <0.001 |
Grandmother had pre-eclampsia in mothers pregnancy% (95% CI) | 3.6 (3.1 to 4.1) | 8.1 (4.8 to 13.4) | 0.004 | 4.8 (3.8 to 6.1) | 0.05 |
Grandmother had gestational hypertension in mothers pregnancy% (95% CI) | 13.6 (12.7 to 14.6) | 21.3 (16.0 to 27.7) | 0.003 | 19.0 (17.1 to 21.1) | <0.001 |
Birth weight of offspring mean (SD) grams | 3302.8 (548.6) | 3036.6 (678.9) | <0.001 | 3330.8 (551.5) | 0.10 |
Gestational age of offspring mean (SD) weeks | 39.5 (1.9) | 38.5 (2.5) | <0.001 | 39.5 (2.0) | 0.67 |
Standard deviation (Z) score of offspring birth weight for gestational age | −0.06 (1.00) | −0.28 (1.01) | 0.003 | −0.04 (0.99) | 0.29 |