| EP with BPD | EP without BPD | All EP | Control | 95% CI of difference (EP–control) | |
| Neonatal characteristics | |||||
| Subjects n | 34 | 15 | 49 | 52 | |
| Boys | 35 | 40 | 37 | 37 | -18–18 |
| Gestational age weeks | 24.8±0.8 | 25.0±0.6 | 24.9±0.7 | 40.1±1.6 | -15.7–14.7*** |
| Birth weight kg | 0.740±0.101 | 0.762±0.093 | 0.747±0.098 | 3.361±0.450 | -2.75–2.48*** |
| Birth weight Z-score# | -0.06±0.71 | -0.03±0.80 | -0.05±0.74 | -0.24±1.14 | -0.57–0.20 |
| BPD | 100 | 0 | 69 | ||
| Post-natal steroids | 70 | 67 | 69 | ||
| Maternal/family details | |||||
| Antenatal steroids | 85 | 87 | 86 | ||
| PROM | 15 | 31 | 19 | ||
| Chorioamnionitis | 21 | 39 | 26 | ||
| Smoking in pregnancy | 25 | 14 | 22 | 22 | -16–17 |
| Current smoking exposure | 18 | 7 | 15 | 26 | -27–4 |
| Maternal asthma | 12 | 0 | 8 | 12 | -16–9 |
| FH of asthma | 38 | 33 | 37 | 33 | -14–22 |
| Maternal ethnicity White | 74 | 87 | 78 | 94 | -30–3* |
| Maternal education after age 16 yrs | 52 | 57 | 53 | 73 | -38–0* |
| Non-manual occupation¶ | 74 | 79 | 76 | 69 | -10–29 |
Data presented as % or mean±sd, unless otherwise indicated. BPD is defined as oxygen given at or beyond 36 weeks post-menstrual age. PROM: prolonged rupture of membranes (>24 h). *: p<0.05; **: p<0.01; ***: p<0.0001. #: according to Child Growth Foundation algorithms 22; ¶: classification based on either parent with a non-manual occupation.