Low versus high activity centres cohorts A and B
| Cohort A (22–25 weeks GA) | Cohort B (26–27 weeks GA) | |||
| Low activity | High activity | Low activity | High activity | |
| N | 461 (49.7%) | 466 (50.3%) | 554 (52.9%) | 493 (47.1%) |
| GA (IQR) | 24.7 (24–25.3) | 24.6 (23.6–25.3) | 26.9 (26.4–27.4) | 27 (26.4–27.4) |
| BW z-score (IQR) | −0.3 (−0.8 to 0.3) | −0.4 (−1 to 0.2) | 0 (−0.7 to 0.5) | 0 (−0.8 to 0.5) |
| Male sex | 51.6% | 57.6% | 52.1% | 55.8% |
| Multiple births | 28.2% | 27.5% | 24.2% | 28.2% |
| Outborn | 3.9% | 2.1% | 5.2% | 3.4% |
| SES (IQR) | 6 (4–8) | 6 (5–8) | 6 (4–8) | 6 (4–8) |
| Activity score (IQR) | 68.1 (68.1–73.7) | 89.2 (87.5–92.7) | 84.2 (83.3–85.8) | 91 (90.2–92.3) |
| Mortality | 71.4% | 51.1% | 18.2% | 10.1% |
| Died in delivery room | 41.9% | 34.1% | 1.6% | 1.8% |
| NICU mortality | 29.5% | 17% | 16.6% | 8.3% |
| Death or NDI | 78.2% | 62.9% | 30.3% | 24.6% |
| Any major morbidity (survivors) | 62.1% | 58.7% | 43.8% | 34.2% |
| Moderate-to-severe NDI (survivors) | 18.3% | 18.6% | 11.9% | 14.3% |
| Age at death in NICU (days) (IQR) | 4 (1.5–10.2) | 8 (1.5–18) | 6 (3–14) | 13 (4–24) |
| Length of stay (days) (IQR) | 73.5 (4–101.8) | 100 (63–120) | 79 (64–95) | 85 (72–97) |
SES, socioeconomic status was calculated by means of a score reflecting both maternal education and paternal occupation, with a maximum and minimum scores of 12 and 2, indicating lower and higher status, respectively.
BW, birth weight; GA, gestational age; NDI, neurodevelopmental impairment; NICU, neonatal intensive care unit.