Infant characteristics and social factors at randomisation
| Infant characteristics | Intervention (N=72) | Control (N=74) |
|---|---|---|
| BW, mean (SD), g | 1396 (429) | 1381 (436) |
| 400–1000 g, n (%) | 20 (28) | 20 (27) |
| 1001–1500 g, n (%) | 15 (21) | 20 (27) |
| 1501–2000 g, n (%) | 37 (51) | 34 (46) |
| GA, mean, (SD), weeks | 30.2 (3.1) | 29.9 (3.5) |
| <28 weeks, n (%) | 17 (24) | 19 (27) |
| 28–32 weeks, n (%) | 36 (50) | 37 (50) |
| ≥33 weeks, n (%) | 19 (26) | 18 (24) |
| SGA* (%) | 11 (13) | 10 (14) |
| Twins, n (%) | 16 (22) | 14 (19) |
| Prenatal steroids, n (%) | 53 (74) | 57 (77) |
| SNAP-II score, mean (SD) | 8.3 (10.9) | 10.4 (11.3) |
| CRIB score, mean (SD) (N=85) | 3.2 (2.8) | 2.7 (2.9) |
| Received ventilation, n (%) | 29 (40) | 37 (50) |
| Duration of ventilation, mean (SD), d (N=66) | 7.0 (18.6) | 7.1 (17.3) |
| Postnatal steroid use, n (%) | 9 (13) | 10 (14) |
| Oxygen therapy at 36 weeks of gestation, n (%) | 11 (15) | 14 (19) |
| Abnormal cerebral ultrasound, n (%) | ||
| IVH grade 1 or 2 | 7 (10) | 8 (11) |
| IVH grade 3 or 4 | 3 (4) | 5 (7) |
| Periventricular leukomalacia | 4 (6) | 8 (11) |
| Maternal and social characteristics | ||
| Mother's age, mean (SD), years | 30.8 (6.1) | 29.1 (6.4) |
| Firstborn children, n (%) | 40 (56) | 37 (54) |
| Mother's education, mean (SD), years (N=131)† | 14.6 (2.8) | 13.5 (3.2) |
| Father’s education mean, (SD), years (N=131)† | 13.8 (3.1) | 13.5 (3.2) |
| Mother's monthly income‡ | 15.8 (7.7) | 14.6 (6.7) |
| Father’s monthly income‡ | 21.1 (8.7) | 19.9 (8.1) |
SNAP-II indicates the Score for Neonatal Acute Physiology II (includes mean blood pressure, lowest temperature, P02/fraction of inspired oxygen ratio, serum pH, multiple seizures and urine output); CRIB, Clinical Risk Index for Babies (includes BW, GA, congenital malformations, maximal base deficits in the first 12 h, minimal appropriate fraction of inspired oxygen in the first 12 h and maximal appropriate fractions of inspired oxygen in the first 12 h).
*SGA, defined as a BW >2 SD below the mean for GA.
†Calculated for 131 families due to 15 twin pairs.
‡Average monthly income (SD) in 1000 Norwegian kroner.
BW, birth weight; GA, gestational age; IVH, intraventricular haemorrhage; SGA, small for gestational age.