Baseline characteristics of the infants and their families
| Characteristics (families) | MRI (n=214)* | Ultrasound (n=220)* |
| Mother’s age at randomisation, median (IQR) | 32.4 (28.8, 37.0) | 32.8 (29.0, 36.6) |
| Maternal ethnicity, n (%) | ||
| White | 110 (52.1) | 104 (47.7) |
| Black or Black British | 38 (18.0) | 55 (25.2) |
| Asian or Asian British | 55 (26.1) | 50 (22.9) |
| Mixed | 4 (1.9) | 4 (1.8) |
| Other ethnicity group | 4 (1.9) | 5 (2.3) |
| Missing | 3 | 2 |
| Mother’s age when leaving full time education, n (%) | ||
| ≤16 years | 26 (12.5) | 19 (9.0) |
| 17–19 years | 33 (15.9) | 33 (15.6) |
| ≥19 years | 142 (68.3) | 151 (71.6) |
| Still in full time education | 7 (3.4) | 8 (3.8) |
| Missing | 6 | 9 |
| Index of multiple deprivation quintiles, n(%) | ||
| 1 | 30 (14.0) | 46 (20.9) |
| 2 | 37 (17.3) | 31 (14.1) |
| 3 | 54 (25.2) | 50 (22.7) |
| 4 | 62 (29.0) | 57 (25.9) |
| 5 | 31 (14.5) | 36 (16.4) |
| Mode of delivery, n (%) | ||
| Emergency caesarean—not in labour | 71 (33.5) | 75 (34·4) |
| Emergency caesarean—in labour | 49 (23.1) | 43 (19·7) |
| Elective section—not in labour | 14 (6.6) | 18 (8.3) |
| Elective section—in labour | 0 (0) | 2 (0.9) |
| Vaginal—forceps assisted | 6 (2.8) | 3 (1.4) |
| Vaginal—spontaneous | 72 (34.0) | 77 (35.3) |
| Missing | 2 | 2 |
| Antenatal steroids, n (%) | ||
| Full | 179 (86.5) | 183 (86.4) |
| Partial | 30 (12.2) | 28 (11.8) |
| None | 5 (2.3) | 9 (4.1) |
| Characteristics (infants) | MRI (n=255)† | Ultrasound (n=255)† |
| Sex: Male, n (%) | 127 (49.8) | 126 (49.4) |
| Gestational age at birth (weeks), median (IQR) | 30 (27, 31) | 30 (27, 31) |
| Birth weight (g), mean (SD) | 1303.5 (393.0) | 1306.0 (387.7) |
| Gestational age at scan (weeks), median (IQR) | 43 (41, 44) | 43 (41, 44) |
| Twin or triplet birth, n (%) | 77 (30.2) | 67 (26.3) |
| Surfactant treatment, n (%) | 139 (54.5) | 138 (54.1) |
| Days ventilated, median (IQR) | 1 (0, 3) | 1 (0, 2) |
| Days on CPAP, median (IQR) | 7 (1, 32) | 7 (2, 28) |
*Number of mothers in each group (MRI and ultrasound).
†Number of infants in each group (MRI and ultrasound).
Index of multiple deprivation quintile group for a valid postcode (1, ≤8.49 (least deprived); 2, 8.5–13.79; 3, 13.8–21.35; 4, 21.36–34.17; 5: ≥34.18 (most deprived); http://tools.npeu.ox.ac.uk/imd/).
CPAP, continuous positive airway pressure.