Baseline characteristics of mothers and their children
| Maternal characteristics | |
| Subjects | 4894 |
| Age years | 30.7±4.8 |
| Ethnicity: Western | 65.4 (3201) |
| BMI kg·m−2 | 23.7 (18.8–35.7) |
| Educational level: higher | 49.2 (2408) |
| Nulliparity: yes | 62.3 (3049) |
| Psychological distress: yes | 9.2 (448) |
| Smoking during pregnancy | |
| No | 74.6 (3.650) |
| Yes: stopped | 9.5 (465) |
| Yes: continued | 15.9 (779) |
| Folic acid use | |
| No | 22.5 (1101) |
| Start before 10 weeks | 32.5 (1593) |
| Pre-conception start | 45.0 (2200) |
| Caesarean section: yes | 13.0 (637) |
| History of asthma or atopy: yes | 41.1 (2.013) |
| Blood pressure | |
| Early pregnancy weeks | 13.2 (10.5–17.5) |
| SBP mmHg | 116±12 |
| DBP mmHg | 69±9 |
| MAP mmHg | 84±9 |
| Mid pregnancy weeks | 20.5 (18.6–23.3) |
| SBP mmHg | 117±12 |
| DBP mmHg | 67±9 |
| MAP mmHg | 84±9 |
| Late pregnancy weeks | 30.4 (28.5–32.9) |
| SBP mmHg | 119±12 |
| DBP mmHg | 69±9 |
| MAP mmHg | 85±9 |
| Hypertensive disorder | |
| Gestational hypertension | 4.2 (206) |
| Pre-eclampsia/HELLP | 1.9 (91) |
| Child characteristics | |
| Sex: female | 50.4 (2467) |
| Birthweight g | 3428±553 |
| Gestational age at birth weeks | 40.1 (35.7–42.4) |
| Inhalant allergies: yes | 34.2 (1673) |
| Current eczema: yes | 9.0 (439) |
| Spirometry | |
| FEV1 L | 2.01±0.30 |
| FVC L | 2.33±0.37 |
| FEV1/FVC | 0.87±0.06 |
| FEF25–75% L·s−1 | 2.69±0.65 |
| FEF75% L·s−1 | 1.14±0.35 |
| Ever-asthma | 9.7 (368) |
| Current wheezing | 18.1 (692) |
| Current asthma | 8.3 (313) |
Data are presented as n, mean±sd, % (n) or median (95% range) based on imputed data; data on maternal blood pressure, hypertensive disorders, lung function, wheezing and asthma were not imputed. BMI: body mass index; SBP: systolic blood pressure; DBP: diastolic blood pressure; MAP: mean arterial pressure; HELLP: haemolysis, elevated liver enzymes and low platelets; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; FEF25–75%: mean forced expiratory flow between 25% and 75% of FVC; FEF75%: forced expiratory flow at 75% of FVC.