Selected demographics of Australian-born and non-Australian-born women
| Australian born, n=15 459 | Non-Australian born, n=18 083 | P values | |
| Maternal age* | 27.7 (5.75) | 29.8 (5.11) | <0.001 |
| Teenage pregnancy | 7.9% | 1.8% | <0.001 |
| Pregnancy ≥35 years | 13.0% | 17.9% | <0.001 |
| Nulliparous | 25.0% | 26.9% | <0.002 |
| Body mass index ≥30 | 28.2% | 17.7% | <0.001 |
| Body mass index ≤18 | 3.0% | 3.0% | 0.02 |
| Private patient | 3.7% | 3.4% | 0.14 |
*Mean and SD.