Clinical characteristics and outcomes of study participants as stratified by gestational age
| Characteristics | Gestational age | ||||
| 22 weeks n=10 | 23 weeks n=90 | 24 weeks n=268 | 25 weeks n=346 | Total n=714 | |
| Male gender (%) | 7 (70) | 52 (57.8) | 137 (51.1) | 193 (55.8) | 389 (54.5) |
| Birth weight, gms (%) | |||||
| <500 | 3 (30) | 7 (7.8) | 12 (4.5) | 11 (3.2) | 33 (4.6) |
| 501–700 | 7 (70) | 77 (85.6) | 160 (59.7) | 82 (23.7) | 326 (45.7) |
| 701–1000 | 0 (0) | 6 (6.7) | 96 (35.8) | 253 (73.1) | 355 (49.7) |
| Mean birth weight, gm (SD) | 542.8 (60.1) | 598.8 (67.5) | 671.9 (92.0) | 773.6 (121.7) | 710.2 (124.2) |
| Indigenous status (%) | 0 (0) | 3 (3.3) | 9 (3.4) | 9 (2.6) | 21 (2.9) |
| Vaginal delivery (%) | 10 (100) | 73 (81.1) | 165 (61.6) | 160 (46.2) | 408 (57.1) |
| Intubated at delivery (%) | 9 (90) | 84 (93.3) | 236 (88.1) | 276 (79.8) | 605 (84.7) |
| Antenatal corticosteroids (%) | 4 (40) | 72 (80) | 228 (85.1) | 259 (74.9) | 563 (78.9) |
| Singleton (%) | 9 (90) | 65 (72.2) | 195 (72.8) | 260 (75.1) | 529 (74.1) |
| Mean CRIB2 Score (SD) | 19.3 (1.3) | 16.1 (1.7) | 14.5 (1.5) | 12.8 (1.6) | 13.9 (2.0) |
| Any major morbidity (%) | 6 (60) | 66 (73.3) | 173 (64.6) | 213 (61.6) | 458 (64.1) |
| Moderate to severe neurodevelopmental impairment (%) | 1 (10) | 13 (14.4) | 28 (10.4) | 33 (9.5) | 75 (10.5) |
| Death | |||||
| Overall (%) | 7 (70) | 47 (52.2) | 130 (48.5) | 104 (30.1) | 288 (40.3) |
| Predischarge death (%) | 7 (70) | 46 (51.1) | 128 (47.8) | 97 (28) | 278 (38.9) |
| Death/major morbidity (%) | 10 (100) | 81 (90) | 233 (86.9) | 254 (73.4) | 578 (81.0) |
| Death/moderate to severe neurodevelopmental impairment (%) | 8 (80) | 60 (66.7) | 158 (59) | 137 (39.6) | 363 (50.8) |
Note: Overall neurodevelopmental assessment follow-up rate was 78%. CRIB: Clinical Risk Index for Babies.