| 1998 | 1997–1999 | 2002 | 2000–2002 |
---|---|---|---|---|
 | Births (%) | DS Births (%) | Births (%) | DS births (%) |
 | N = 61 080 | N = 166 | N = 61 883 | N = 180 |
Marital status | ||||
No partner | 12.3 | 7.8 | 12.5 | 12.8 |
Married or de facto | 87.6 | 92.2 | 87.3 | 86.7 |
Unknown | 0.1 | 0.0 | 0.1 | 0.5 |
 | *p = 0.08 |  | *p = 0.90 |  |
Parity | ||||
Primigravid | 40.2 | 28.3 | 42.0 | 29.4 |
Multigravid | 59.8 | 71.7 | 58.0 | 70.6 |
 | *p < 0.01 |  | *p < 0.001 |  |
Region of mother's birth | ||||
Australia | 76.1 | 75.3 | 76.3 | 71.7 |
Overseas | 23.7 | 24.7 | 23.5 | 28.3 |
Unknown | 0.2 | 0.0 | 0.2 | 0.0 |
 | *p = 0.81 |  | *p = 0.15 |  |
Hospital category | ||||
Public | 74.3 | 73.5 | 68.1 | 75.6 |
Private | 25.7 | 26.5 | 31.9 | 24.4 |
 | *p = 0.81 |  | *p = 0.03 |  |
Region of mother's residence | ||||
Rural | 27.7 | 25.3 | 26.3 | 32.8 |
Metropolitan | 72.3 | 74.7 | 73.7 | 67.2 |
 | *p = 0.49 |  | *p = 0.05 |  |