Table 1 Birth, medical and demographic information
PI group | PC group | TR group | |
|---|---|---|---|
N =72 | N =74 | N =75 | |
Infant characteristics | 1,396 ± 429 | 1,381 ± 436 | 3,619 ± 490 |
BW, mean ± SD, g | 20 (28) | 20 (27) | |
400 to 1000 g, n (%) | 15 (21) | 20 (27) | |
1001 to 1500 g, n (%) | 37 (51) | 34 (46) | |
1501 to 2000 g, n (%) | 30.2 ± 3.1 | 29.9 ± 3.5 | 39.3 ± 1.3 |
GA, mean ± SD, week | 17 (24) | 19 (27) | |
<28 week, n (%) | 36 (50) | 19 (27) | |
28 to 32 week, n (%) | 38 (53) | 37 (50) | |
≥33 week, n (%) | 16 (22) | 18 (24) | |
Boy, n (%) | 38 (53) | 39 (53) | 40 (54) |
Twin, n (%) | 16 (22) | 14 (19) | 0 |
Prenatal steroid use, n (%) | 53 (74) | 57 (77) | |
SNAP II, 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, n (%) | 7.0 ± 18.6 | 7.1 ± 17.3 | |
Postnatal steroid use, n (%) | 9 (13) | 10 (14) | |
Oxygen therapy at 38 week GA, 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 | 29.7 ± 6.1 |
First-born child, n (%) | 40 (56) | 37 (54) | 27 (37) |
Mother’s education, mean ± SD, years, N =131 | 14.6 ± 2.8 | 13.5 ± 3.2 | 14.9 ± 2.8 |
Father’s education, mean ± SD, years, N =131 | 13.8 ± 3.1 | 13.5 ± 3.2 | 14.4 ± 3.2 |
Mother’s monthly income, mean ± SD, 1,000 Norwegian kroner, N =131 | 15.8 ± 7.7 | 14.6 ± 6.7 | 15.9 ± 8.0 |
Father’s monthly income, mean ± SD, 1,000 Norwegian kroner, N =131 | 21.1 ± 8.7 | 19.9 ± 8.1 | 21.9 ± 9.8 |