Characteristics of infants with and without ROP
| No ROP (n=206) | ROP (n=76) | p Value | |
| Gestational age (weeks), median (IQR) | 29 (28–30) | 26 (25–28) | 0.00 |
| Birth weight (g), median (IQR) | 1250 (1027–1427) | 790 (680–964) | 0.00 |
| SNAP-PE II , median (IQR) | 14 (5–24) | 32 (19–48) | 0.00 |
| Oxygen (days), median (IQR) | 5 (12–28) | 69 (31–95) | 0.00 |
| Ventilator (days), median (IQR) | 1 (0–2) | 11 (2–25) | 0.00 |
| Pre-eclampsia, n (%) | 71 (34.5) | 26 (34.2) | 0.54 |
| C-section, n (%) | 124 (60.2) | 51 (67.1) | 0.17 |
| Caucasian, n (%) | 163 (79.1) | 51 (67.1) | 0.02 |
| Multiples, n (%) | 24 (11.7) | 6 (7.9) | 0.25 |
| Chorioamnionitis, % | 66 (32.0) | 32 (42.1) | 0.07 |
| Males, n (%) | 115 (55.9) | 36 (47.4) | 0.13 |
| IUGR, n (%) | 22 (10.7) | 17 (22.4) | 0.01 |
| RDS, n (%) | 145 (70.4) | 71 (93.4) | 0.00 |
| Surfactant, n (%) | 96 (46.6) | 58 (76.3) | 0.00 |
| PDA, n (%) | 60 (29.1) | 54 (71.1) | 0.00 |
| Positive blood cultures, n (%) | 18 (8.7) | 21 (27.6) | 0.00 |
| Blood transfusion, n (%) | 32 (15.5) | 47 (61.8) | 0.00 |
| IVH, n (%) | 16 (7.8) | 19 (25.0) | 0.00 |
| Grades 3 and 4, IVH, n (%) | 3 (1.5) | 6 (7.9) | 0.00 |
| NEC, n (%) | 4 (1.9) | 9 (11.8) | 0.00 |
| BPD, n (%) | 28 (13.6) | 50 (65.8) | 0.00 |
BPD, bronchopulmonary dysplasia; C-section, caesarean section; IUGR, intrauterine growth restriction; IVH, intraventricular haemorrhage; NEC, necrotising enterocolitis; PDA, patent ductus arteriosus; RDS, respiratory distress syndrome; ROP, retinopathy of prematurity; SNAP-PE, Score for Neonatal Acute Physiology-Physiological Extension.