| Characteristic | No or mild BPD | Moderate or severe BPD | p-value |
| Subjects n | 49 | 13 | |
| Males/females n | 26/23 | 9/4 | 0.36 |
| Born before 28 weeks | 9 (18.4) | 5 (38.5) | 0.50 |
| Gestational age weeks | 32.1±3.1 | 29.7±3.2 | 0.02 |
| Birth weight g | 1794±556 | 1256±488 | 0.002 |
| Length cm | 42.4±4.5 | 38.0±6.1 | 0.005 |
| OFC cm | 29.2±3.0 | 27.0±3.2 | 0.03 |
| Maternal smoking | 4 (8.2) | 2 (15.4) | 0.60 |
| Pre-eclampsia | 10 (20.4) | 3 (23.1) | 1.00 |
| Diabetes | 4 (8.2) | 2 (15.4) | 0.60 |
| Prenatal corticosteroids | 34 (69.4) | 10 (90.9) | 0.26 |
| Caesarean section | 22 (44.9) | 8 (61.5) | 0.36 |
| Maternal antibiotics | 43 (87.8) | 10 (76.9) | 0.38 |
| Chorioamnionitis | 9 (19.1) | 1 (7.7) | 0.44 |
| IUGR | 3 (6.1) | 3 (23.1) | 0.10 |
| Apgar score | |||
| 1 min | 7 (5–8) | 5 (2–7) | 0.004 |
| 5 min | 9 (7–9) | 7 (4–8) | 0.003 |
| Ventilator days | 0 (0–2) | 4 (1–26) | <0.001 |
| CPAP days | 1 (0–3) | 4 (2–19) | 0.02 |
| CPAP plus ventilator days | 2 (0–6) | 9 (7–37) | <0.001 |
| Total supplemental O2 days | 11 (0–43) | 67 (60–93) | <0.001 |
| Intraventricular haemorrhage | 1 (2.0) | 4 (30.8) | 0.006 |
| ROP | |||
| Abnormal exam | 15 (30.6) | 9 (69.2) | 0.02 |
| Laser treatment | 1 (2.0) | 0 (0) | 1.00 |
| Necrotising enterocolitis | 2 (14.1) | 1 (7.7) | 0.51 |
| Patent ductus arteriosus | 2 (4.1) | 7 (53.8) | <0.001 |
| Post-natal sepsis | 4 (8.2) | 0 (0) | 0.57 |
Data are presented as n (%), mean±sd or median (interquartile range), unless otherwise stated. Bold indicates statistical significance. BPD: bronchopulmonary dysplasia; OFC: occipitofrontal circumference; IUGR: intrauterine growth restriction; CPAP: continuous positive airway pressure; ROP: retinopathy of prematurity.