Gestational age (GA), birth weight (BW), stage of retinopathy of prematurity (ROP) at first examination, final stage of ROP and treatment in 404 infants with ROP in at least one eye at the first examination
| GA (weeks) | 21/22 n=12 | 23 n=51 | 24 n=47 | 25 n=54 | 26 n=53 | 27 n=42 | 28 n=44 | 29 n=67 | 30 n=34 | Total n=404 |
| GA (weeks) | 22.6 (22.3:22.6) | 23.4 (23.0:23.6) | 24.3 (24.0:24.6) | 25.3 (25.0:25.6) | 26.3 (26.0:26.6) | 27.3 (27.0:27.6) | 28.3 (28.0:28.6) | 29.3 (29.0:29.6) | 30.4 (30.0:30.6) | 26.5 (22.3:30.6) |
| BW (g) | 531.5 (455:618) | 615.0 (420:760) | 705.0 (430:860) | 790.0 (477:1047) | 841.0 (415:1890) | 1027.5 (599:1300) | 1139.5 (658:1564) | 1195.0 (716:1690) | 1334.0 (805:1840) | 860.0 (415:1890) |
| ROP at first examination* | ||||||||||
| 1 | 4 (33.3) | 28 (54.9) | 29 (61.7) | 26 (48.1) | 31 (58.5) | 27 (64.3) | 33 (75.0) | 45 (67.2) | 28 (82.4) | 251 (62.1) |
| 2 | 6 (50.0) | 20 (39.2) | 14 (29.8) | 23 (42.6) | 19 (35.8) | 14 (33.3) | 11 (25.0) | 22 (32.8) | 6 (17.6) | 135 (33.4) |
| 3 | 2 (16.7) | 3 (5.9) | 4 (8.5) | 4 (7.4) | 3 (5.7) | 1 (2.4) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 17 (4.2) |
| 4 | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (1.9) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.2) |
| Final ROP stage | ||||||||||
| 1 | 2 (16.7) | 5 (9.8) | 9 (19.1) | 8 (14.8) | 10 (18.9) | 14 (33.3) | 21 (47.7) | 37 (55.2) | 16 (47.1) | 122 (30.2) |
| 2 | 1 (8.3) | 13 (25.5) | 6 (12.8) | 27 (50.0) | 24 (45.3) | 23 (54.8) | 17 (38.6) | 27 (40.3) | 13 (38.2) | 151 (37.4) |
| 3 | 8 (66.7) | 33 (64.7) | 31 (66.0) | 18 (33.3) | 19 (35.8) | 5 (11.9) | 6 (13.6) | 3 (4.5) | 5 (14.7) | 128 (31.7) |
| 4 | 1 (8.3) | 0 (0.0) | 0 (0.0) | 1 (1.9) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 2 (0.5) |
| 5 | 0 (0.0) | 0 (0.0) | 1 (2.1) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.2) |
| Treated ROP | 9 (75.0) | 22 (43.1) | 22 (46.8) | 13 (24.1) | 8 (15.1) | 1 (2.4) | 2 (4.5) | 0 (0.0) | 0 (0.0) | 77 (19.1) |
*Stage of ROP (worst eye if different stages right/left eye).