Table 1: Score for the assessment of ultrasound scans at time 0 and time 1 (after 15 days).
| Ultrasound scan assessment | ||
| Score: 0-6 points | ||
| Periventricular echodensity PVL (0-3 points) | Absent | 0 points |
| Mild | 1 point | |
| Moderate | 2 points | |
| De Vries’ score for PVL (0-3 points) | No PVL | 0 points |
| Grade 1 | 1 point | |
| Grade 2 | 2 points | |
| Grade 3 | 3 points | |