Characteristics of 14 656 eligible registrants
| Characteristic | No. with data | Value | Eligible registrants |
| Maternal age (mean (SD))* | 14 617 | Years | 30.4 (5.8) |
| Assisted conception in this pregnancy? (n (%))* | 14 274 | Yes | 519 (3.6) |
| Maternal antibiotics <48 hours (mean (SD))* | 13 065 | Yes | 2962 (22.7) |
| Plurality (n (%)) | 14 656 | Multiple | 332 (2.3) |
| Fetal distress? (n (%)) | 14 625 | Yes | 4427 (30.3) |
| Non-cephalic presentation (n (%)) | 14 565 | Yes | 909 (6.2) |
| Vaginal | 5249 (36.3) | ||
| Mode of delivery (n (%)) | 14 477 | Instrumental | 2341 (16.2) |
| Caesarean section | 6887 (47.6) | ||
| Gestation (mean (SD))† | 14 656 | Completed weeks | 38.9 (1.4) |
| Weight (mean (SD)) | 14 656 | Gram | 3406 (578) |
| Intrauterine growth restriction? (n (%)) | 14 631 | Yes | 845 (5.8) |
| Sex (n (%)) | 14 652 | Male | 9085 (62.0) |
| Apgar score at 1 min (mean (SD)) | 0–3 | 2753 (18.8) | |
| 14 606 | 4–6 | 4015 (27.5) | |
| 7–10 | 7838 (53.7) | ||
| Apgar score at 5 min (mean (SD)) | 0–3 | 615 (4.2) | |
| 14 612 | 4–6 | 2433 (16.7) | |
| 7–10 | 11 564 (79.1) | ||
| Intubated at resuscitation? (n (%)) | 14 642 | Yes | 1683 (11.5) |
| Congenital anomaly? (n (%)) | 14 649 | Yes | 2211 (15.1) |
| Age at admission (median (IQR)) | 14 634 | Hours | 1.0 (0.0–1.0) |
*Collection is based on ANZNN registered infants, so some twin mothers will have been counted twice.
†Calculated based on completed weeks only, as days not recorded for 1616 infants.
ANZNN, Australian and New Zealand Neonatal Network.