Table I.
Neonatal and demographic characteristics of participants
| Characteristic | All participants (n=193) |
Excluding infants with cerebral palsy at 2y (n=178) |
|---|---|---|
| Gestational age, wk | ||
| Mean (SD) | 27.5 (1.9) | 27.5 (1.9) |
| Range | 22–32 | 22–32 |
| Birthweight, g | ||
| Mean (SD) | 962 (220) | 965 (221) |
| Range | 414–1425 | 414–1425 |
| Birthweight z-score | ||
| Mean (SD) | −0.55 (0.93) | −0.54 (0.93) |
| Range | −3.54 to 1.15 | −3.54 to 1.15 |
| n (%) | n (%) | |
| Males/Females | 97/96 | 89/89 |
| Twins/triplets | 77 (39) | 73 (41) |
| High social risk (score≥2)a | 115 (60) | 105 (60) |
| Number missing | 2 | 2 |
| Bronchopulmonary dysplasiaa | 62 (32) | 57 (32) |
| Number missing | 1 | 1 |
| Postnatal corticosteroidsa | 17 (9) | 15 (8) |
| Number missing | 1 | 1 |
| Necrotizing enterocolitis (including suspected) | 16 (8) | 13 (7) |
| Sepsisa | 54 (33) | 47 (31) |
| Number missing | 27 | 24 |
| Grade 3/4 intraventricular haemorrhage | 7 (4) | 6 (3) |
| Cystic periventricular leukomalacia | 7 (4) | 5 (3) |
| White matter abnormalities on MRI | ||
| Nil | 61 (32) | 61 (34) |
| Mild | 102 (53) | 94 (53) |
| Moderate–severe | 30 (16) | 23 (13) |
a
Percentages of those with data available. MRI, magnetic resonance imaging.