Adverse neonatal outcomes according to gestational weeks at birth
| Outcome | Week 37 (n=1185) | Week 38 (n=7227) | Week 39 (n=7656) | Week 40 (n=3069) | Week ≥41 (n=802) | p for trend * |
| Adverse respiratory outcome | ||||||
| Respiratory distress syndrome—no (%) | 19 (1.6) | 42 (0.6) | 19 (0.2) | 14 (0.5) | 5 (0.6) | <0.001/0.076 |
| Transient tachypnoea of the newborn—no (%) | 36 (3.0) | 118 (1.6) | 55 (0.7) | 45 (1.5) | 18 (2.2) | <0.001/<0.001 |
| Respiratory complications—no (%) | 53 (4.5) | 154 (2.1) | 73 (1.0) | 58 (1.9) | 23 (2.9) | <0.001/<0.001 |
| Neonatal infection—no (%) | 12 (1.0) | 26 (0.4) | 22 (0.3) | 17 (0.6) | 4 (0.5) | <0.001/0.103 |
| Hypoxic ischaemic encephalopathy—no (%) | 2 (0.2) | 1 (0) | 1 (0) | 1 (0) | 2 (2.5) | 0.005/0.003 |
| Meconium aspiration syndrome—no (%) | 1 (0.1) | 1 (0) | 0 | 1 (0) | 0 (0) | 0.055/0.252 |
| Necrotising enterocolitis—no (%) | 6 (0.5) | 5 (0.1) | 1 (0) | 1 (0) | 2 (2.5) | <0.001/0.003 |
| Neonate deaths—no (%)† | 0 (0) | 2 (0) | 2 (0) | 1 (0) | 0 (0) | 0.712/0.879 |
| Hyperbilirubinaemia—no (%) | 24 (2.0) | 54 (0.7) | 47 (0.6) | 22 (0.7) | 4 (0.5) | <0.001/0.735 |
| Treated hypoglycaemia—no (%) | 23 (1.9) | 59 (0.8) | 41 (0.5) | 23 (0.7) | 16 (2.0) | <0.001/<0.001 |
| NICU admission—no (%) | 87 (7.3) | 206 (2.9) | 165 (2.2) | 91 (3.0) | 27 (3.4) | <0.001/0.011 |
| Hospitalisation ≥5 days | 56 (4.7) | 71 (1.0) | 52 (0.7) | 38 (1.2) | 13 (1.6) | <0.001/0.002 |
*The p value was calculated by the Cochran–Armitage test for trend for the period from 37 weeks to 39 weeks and from 39 weeks to ≥41 weeks, respectively.
†There were five neonatal deaths, one intrapartum stillbirth due to amniotic fluid embolism during operation.
NICU, neonatal intensive care unit.