Maternal characteristics of the study group stratified by admitting hospital A to H
| Characteristic | A (n=1225) | B (n=1000) | C (n=963) | D (n=889) | E (n=856) | F (n=848) | G (n=785) | H (n=646) | All (n=7212) |
| Maternal age, years | 29.0(24.0–33.0) | 30.0(26.0–35.0) | 29.0 (25.0–34.0) | 32.0 (28.0–36.0) | 32.0 (27.0–36.0) | 32.0 (28.0–36.0) | 29.0 (24.0–33.0) | 30.0 (26.0–34.0) | 30.0(26.0–35.0) |
| Indigenous Australian | 129 (10.5) | 34 (3.4) | 39 (4.0) | 38 (4.3) | 43 (5.0) | 24 (2.8) | 70 (8.9) | 49 (7.6) | 426 (5.9) |
| Assisted conception | 105 (8.6) | 156 (15.6) | 104 (10.8) | 136 (15.3) | 129 (15.1) | 141 (16.6) | 77 (9.8) | 73 (11.3) | 921 (12.8) |
| Multiple pregnancy | 338 (27.6) | 271 (27.1) | 276 (28.7) | 279 (31.4) | 251 (29.3) | 244 (28.8) | 185 (23.6) | 205 (31.7) | 2049 (28.4) |
| Hypertension in pregnancy | 231 (18.9) | 216 (21.6) | 143 (14.8) | 202 (22.7) | 165 (19.3) | 153 (18.0) | 157 (20.0) | 121 (18.7) | 1388 (19.2) |
| Chorioamnionitis | 161 (13.1) | 293 (29.3) | 229 (23.8) | 152 (17.1) | 297 (34.7) | 232 (27.4) | 111 (14.1) | 219 (34.0) | 1694 (23.5) |
| Intrauterine growth restriction | 145 (11.8) | 158 (15.8) | 123 (12.8) | 166 (18.7) | 143 (16.7) | 124 (14.6) | 100 (12.7) | 84 (13.0) | 1043 (14.5) |
| Antenatally diagnosed malformation | 19 (1.6) | 27 (2.7) | 20 (2.1) | 34 (3.8) | 4 (0.5) | 10 (1.2) | 9 (1.1) | 20 (3.1) | 143 (2.0) |
| Any antenatal steroids | 1119 (91.3) | 849 (84.9) | 885 (91.9) | 822 (92.5) | 805 (94.0) | 780 (92.0) | 712 (90.7) | 588 (91.0) | 6560 (91.0) |
| Vaginal breech delivery | 82 (6.7) | 84 (8.4) | 63 (6.5) | 54 (6.1) | 28 (3.3) | 34 (4.0) | 36 (4.6) | 39 (6.0) | 420 (5.8) |
| Caesarean section | 681 (55.6) | 594 (59.4) | 561 (58.3) | 578 (65.0) | 601 (70.2) | 551 (65.0) | 517 (65.9) | 385 (59.6) | 4468 (62.0) |
Data are presented as median (IQR) for maternal age and n (%) for all other variables. Chorioamnionitis includes clinically suspected as well as pathologically proven cases.