| ROP stage | No. (%) | Mean gestational age (weeks) (range) | Mean birth weight (g) (range) |
| No ROP | 73 (44) | 31.8 (27 to 36) | 1521 (900 to 2500) |
| Stage I | 53 (32) | 30.8 (25 to 35) | 1421 (790 to 3300) |
| Stage II | 25 (15) | 29.4 (26 to 34) | 1231 (650 to 2100) |
| Stage III | 13 (7.8) | 29.2 (25 to 34) | 1145 (750 to 1800) |
| Threshold | 2 (1.2) | 26.5 (25 to 28) | 775 (750 to 800) |