Table 3 Participant characteristics by parity compared to state and national birthing populations

n (%)

n (%)

n (%)

n (%)

n (%)

Age yrs Mean (SD, range)

28.8 yrs (5.2, 17 to 42)

30.1 yrs (5.2, 18 to 51)

28.8 yrs (5.5, 17 to 51)

29.2 yrs (ns, <20 to >40)^a

30 yrs (ns,<15 to 60)^a

Missing

-

1 ( 0.1)

1 (0.1)

-

74 (0.0)^a

Marital status

Single/divorced/separated

38 ( 6.2)

59 ( 7.4)

97 (6.8)

7,334 (11.9)^b

-

Married/defacto/relationship

566 (93.0)

741 (92.5)

1307 (92.8)

52,834 (86.5)^b

64% (All)^c

Missing/Other

5 (0.8)

1 (0.1)

6 (0.4)

937 (1.5)^b

Education

606 (99.5)

800 (99.9)

1406 (99.7)

-

-

≤Year 12

307 (50.4)

395 (49.3)

702 (49.8)

-

-

Post Year 12

299 (49.1)

405 (50.6)

704 (49.9)

-

-

Missing

3 (0.5)

1 (0.1)

4 (0.3)

Employment

605 (99.3)

798 (99.6)

1403 (99.5)

Full time/part-time

519 (85.2)

498 (62.2)

1017 (72.1)

1,474,107 (74)^c

7,203,234 (73)^c

No paid work

86 (14.1)

300 (37.4)

386 (27.4)

507,319 (26)^c

2,652,926 (27)^c

Missing

4 (0.7)

3 (0.4)

7 (0.5)

Income

570 (93.6)

769 (96.0)

1339 (95.0)

<$52,000

170 (28.0)

239 (29.8)

409 (29.0)

569,175 (41)^c

2,844,563 (41)^c

≥$52,000

400 (65.6)

530 (66.2)

930 (66.0)

1,390,246 (59)^c

6,935,474 (59)^c

Missing

39 (6.4)

32 (4.0)

71 (5.0)

Country of birth

Australia

455 (74.7)

591 (73.8)

1046 (74.2)

47,190 (77.3)^a

210,382 (71.4)^a

Other

132 (21.7)

193 (24.1)

325 (23.0)

13,792 (22.6)^a

82,740 (28.0)^a

Missing

22 (3.6 )

17 (2.1)

39 (2.8)

38 (0.1)^a

1,692 (0.6)^a

Aboriginal Torres Straits Islander

12 ( 2.0)

15 (1.9)

27 (1.9)

3,504 (5.7)^a

11,494 (3.9)^a

Missing

-

2 (0.2)

2 (0.1)

-

792 (0.3)^a

BMI Mean (SD, range)^a = Mean (n,%)

26.2 (5.9, 15.8 to 59.2)

27.0 (6.4, 13.4 to 78.4)

26.7 (6.2, 13.4 to 78.4)

25.9 (59,522, 97.5)^a

26.0 (79,432, 82.4)^a

<18.5 n (%)

10 (1.6)

11 (1.4)

29 (2.0)

2,625 (4.4)^a

3,273 (4.1)^a

18.5 – 24.9 n (%)

296 (48.6)

327 (40.8)

615 (43.6)

27,262 (45.8)^a

36,488 (45.9)^a

25.0 - 29.9 n (%)

154 (25.3)

221 (27.6)

375 (26.6)

16,419 (27.6)^a

21,851 (27.5)^a

>30 n (%)

110 (18.1)

190 (23.7)

300 (21.3)

13,216 (22.2)^a

17,820 (22.4)^a

Missing n (%)

39 (6.4)

52 (6.5)

91 (6.5)

1,498 (2.5)^a

16,930 (17.6)^a

Obstetric factors

Nulliparous

609 (100)

-

609 (43.2)

24,876 (40.8)^a

93,482 (42.1)^a

Multiparous

-

801 (100)

801 (56.8)

36,144 (59.2)^a

128,608 (57.9)^a

Characteristics of last birth

Non operative vaginal

-

-

522 (65.2)

35,071 (57.5)^a

166,208 (56.4)^a

Operative vaginal

-

-

78 (9.7)

5,892 ( 9.7)^a

35,405 (12.0)^a

Caesarean section

-

-

194 (24.2)

20,057 (32.9)^a

93,157 (31.6)^a

Labour/CS

-

-

131 (16.4)

7,450 (12.2)^a

38,274 (13.0)^a

No labour/CS

-

-

63 (7.9)

12,607 (20.7)^a

54,876 (18.6)^a

Missing

-

-

7 (0.9)

-

51 (0.0)^a

Last Birth Pre-term

-

-

57 (7.1)

4,754 (7.8)^a

22,004 (7.5)^a

Last Birth Term

-

-

737 (92.1)

56,260 (92.2)^a

272,760 (92.5)^a

Missing

-

-

6 (0.8)

6 (0.0)^a

50 (0.0)^a

Live born

-

-

784 (97.9)

61,612 (98.9)^a

297,357 (99.3)^a

Stillborn

-

-

7 (0.87)

413 ( 0.7)^a

2,206 (0.7)^a

Neonatal death

-

-

3 (0.4)

235 (0.4)^a

641 (0.2)^a