Antenatal characteristics
| Neonatal encephalopathy (n=1494) | Neonatal encephalopathy with sepsis (n=38) | P value | |
| Maternal age, years (IQR) | 30 (26–47) | 29.5 (27–32) | 0.2 |
| Ethnicity (%) | |||
| Aboriginal | 41 (3) | 1 (2) | 0.68 |
| Asian | 224 (15) | 9 (23) | 0.99 |
| Caucasian | 967 (64) | 20 (50) | 0.18 |
| Indigenous, other | 50 (3) | 1 (2) | 0.09 |
| Pacific | 49 (3) | 3 (8) | 0.99 |
| Māori | 91 (6) | 4 (10) | 0.15 |
| Not specified | 91 (6) | 2 (5) | 0.3 |
| Presenting problem (%) | |||
| Preterm prologed rupture of membranes (PPROM) | 19 (2) | 3 (8) | 0.02 |
| Preterm labour | 19 (2) | 0 (0) | 0.13 |
| Hypertension | 88 (6) | 3 (8) | 0.51 |
| Antepartum haemorrhage (APH) | 91 (6) | 1 (3) | 0.73 |
| Intrauterine growth restriction (IUGR) | 28 (2) | 0 (0) | 0.1 |
| Fetal distress | 637 (42) | 18 (45) | 0.75 |
| Spontaneous labour, term | 438 (29) | 13 (33) | 0.6 |
| Fetal malformation | 5 (0.3) | 0 (0) | |
| Not specified | 203 (13) | 3 (8) | 0.35 |
| Previous perinatal death (%) | 25 (2) | 1 (2) | 0.5 |
| Plurality, twins (%) | 40 (3) | 1 (2) | 0.99 |
| Twins (%) | |||
| First born | 12 (30) | 1 (100) | <0.001 |
| Second born | 28 (70) | 0 (0) | |
| Gestation (IQR) | 39 (38–40) | 39 (38–40) | 0.64 |
| Birth weight, g (IQR) | 3385 (3000–3730) | 3413 (3093–3903) | 0.25 |
| Male (%) | 848 (56) | 24 (60) | 0.25 |
| Delivery (%) | |||
| Vaginal | 459 (31) | 14 (35) | 0.81 |
| Instrumental vaginal | 317 (21) | 2 (5) | 0.01 |
| Caesarean in labour | 493 (33) | 17 (43) | 0.23 |
| Caesarean without labour | 233 (15) | 7 (18) | 0.66 |
| Not specified | 11 (0.7) | 0 (0) | – |
| Breech (%) | 94 (6) | 3 (8) | 0.74 |
Data are presented as median (IQR) or n (%). The Mann-Whitney U test and the Pearson χ2 test or the Fisher’s exact test were used for comparison between groups.