Characteristic | Participants, n=189 | Non-participants, n=12 | P value |
Gestational age at birth in weeks, mean (SD) | 34.4 (1.3) | 34.6 (1.0) | 0.5 |
Birth weight in grams, mean (SD) | 2160 (455) | 2181 (593) | 0.9 |
Birth weight z-score, mean (SD) | −0.3 (1.1) | −0.5 (1.6) | 0.7 |
Small for gestational age, n (%) | 17 (9) | 3 (25) | 0.07 |
Males, n (%) | 90 (48) | 6 (50) | 0.9 |
Multiple births, n (%) | 71 (38) | 3 (25) | 0.4 |
Intraventricular haemorrhage (any), n (%) | 0 (0) | 0 (0) | NA |
Cystic periventricular leucomalacia, n (%) | 0 (0)n=188 | 0 (0)n=10 | NA |
Antenatal corticosteroids, n (%) | 115 (61) | 6 (50) | 0.5 |
Higher social risk, n (%) | 62 (34)n=184 | 4 (36)n=11 | 0.9 |
Some cells are NA when P values could not be calculated because both groups are 0. Some measures do not have data for the total n=189 participants; in these cases, the number of infants who contributed data are provided as superscripts.
NA, not applicable.