Comparison of clinical parameters between infants with and without IVH
| IVH (n=12 163) | No IVH (n=43 038) | P value | OR (95% CI) | |
| Mean maternal age (SD) | 28.5 (7.1) | 29.2 (6.7) | <0.001 | |
| Maternal ethnicity (%) | ||||
| Indigenous* | 1455 (11.9) | 4786 (11.1) | 0.01 | 1.1 (1.0 to 1.1) |
| Asian | 809 (6.7) | 2956 (6.9) | 0.4 | 1.0 (0.9 to 1.0) |
| Caucasian | 8335 (68.5) | 30 078 (69.9) | 0.01 | 0.9 (0.9 to 1.0) |
| Other | 200 (1.6) | 733 (1.7) | 0.7 | 1.0 (0.7 to 1.1) |
| Assisted conception (%) | 1223 (11.7) | 4658 (12.6) | 0.01 | 0.9 (0.9 to 1.0) |
| Multiple gestation (%) | 2924 (24.0) | 12 793 (29.7) | <0.001 | 0.8 (0.7 to 0.8) |
| Vaginal birth (%) | 6615 (54.7) | 14 681 (34.4) | <0.001 | 2.5 (2.0 to 2.5) |
| PROM >24 hours (%) | 2575 (22.8) | 8701 (21.5) | <0.01 | 1.0 (1.0 to 1.1) |
| PIH (%) | 1354 (11.5) | 8128 (19.2) | <0.001 | 0.6 (0.5 to 0.6) |
| APH (%) | 2737 (23.5) | 9292 (22.2) | <0.01 | 1.1 (1.0 to 1.1) |
| Antenatal steroids (%) | 9763 (83.0) | 36 627 (88.0) | <0.001 | 0.7 (0.6 to 0.7) |
| GA ≤27 weeks (%) | 6523 (53.6) | 11 555 (26.8) | <0.001 | 3.2 (3.0 to 3.3) |
| Mean GA, weeks (SD) | 27.2 (2.4) | 28.7 (2.1) | <0.001 | |
| Mean birth weight, g (SD) | 1070 (374) | 1239 (373) | <0.001 | |
| SGA (%) | 315 (2.6) | 1329 (3.1) | <0.01 | 0.8 (0.7 to 0.9) |
| Outborn (%) | 2034 (17.2) | 4890 (11.5) | <0.001 | 1.7 (1.4 to 1.7) |
| Male (%) | 7042 (57.9) | 22 945 (53.4) | <0.001 | 1.3 (1.1 to 1.3) |
| Apgar score <7 at 5 min (%) | 3100 (25.5) | 5669 (13.2) | <0.001 | 2.5 (2.0 to 2.5) |
| Congenital anomalies (%) | 833 (7.1) | 2311 (5.5) | <0.001 | 1.3 (1.3 to 1.4) |
| Surfactant (%) | 8770 (72.5) | 21 892 (51.5) | <0.001 | 2.5 (2.0 to 2.5) |
| Survival (%) | 9876 (81.2) | 40 947 (95.1) | <0.001 | 0.2 (0.2 to 0.2) |
| Other major morbidities† (%) | 4194 (34.5) | 8386 (19.5) | <0.001 | 2.0 (2.0 to 2.5) |
*Includes person of Aboriginal or Torres Strait Islander descent, Pacific Islander background or Maori.
†Having any one or more of: NEC stage 2 or higher, BPD, stage 3 or higher ROP, excluding severe IVH.
APH, antepartum haemorrhage; BPD, bronchopulmonary dysplasia; GA, gestational age; IVH, intraventricular haemorrhage; NEC, necrotising enterocolitis; PIH, pregnancy-induced hypertension; PROM, prolonged rupture of membrane; ROP, retinopathy of prematurity; SGA, small for gestational age.