Association between demographics and interpregnancy interval following a live birth
| Demographic characteristic | IPI <12 months (%) | IPI ≥12 months (%) | Total | X2 |
| Age (years) | ||||
| <25* | 13 (18.1) | 25 (9.2) | 38 | p=0.043 |
| 25–34 | 45 (62.5) | 166 (61) | 211 | |
| >34† | 14 (19.4) | 81 (29.8) | 95 | |
| Total | 72 (100.0) | 272 (100.0) | 344 | |
| Ethnicity | ||||
| Australian | 3 (4.2) | 15 (5.5) | 18 | p=0.075 |
| Indian Subcontinent | 18 (25.0) | 79 (29.0) | 97 | |
| Asian | 16 (22.2) | 72 (26.5) | 88 | |
| African/Middle Eastern | 14 (19.4) | 19 (7.0) | 33 | |
| European | 7 (9.7) | 25 (9.2) | 32 | |
| ATSI | 1 (1.4) | 6 (2.2) | 7 | |
| Other | 7 (9.7) | 17 (6.3) | 24 | |
| Unknown | 6 (8.3) | 39 (14.3) | 45 | |
| Total | 72 (100.0) | 272 (100.0) | 344 | |
| Relationship status‡ | ||||
| Single§ | 2 (2.9) | 18 (6.6) | 20 | p=0.194 |
| Partnered¶ | 67 (97.1) | 256 (93.4) | 323 | |
| Total | 69 (100.0) | 274 (100.0) | 343 | |
| Education‡ | ||||
| Tertiary | 36 (50.7) | 144 (53.7) | 180 | p=0.525 |
| High school/TAFE | 32 (45.1) | 105 (39.2) | 137 | |
| Primary | 3 (4.2) | 19 (7.1) | 22 | |
| Total | 71 (100.0) | 268 (100.0) | 339 | |
| Religion | ||||
| None | 18 (25.0) | 100 (36.8) | 118 | p=0.150 |
| Christian | 22 (30.6) | 63 (23.2) | 85 | |
| Muslim | 26 (36.1) | 77 (28.3) | 103 | |
| Other | 6 (8.3) | 32 (11.8) | 38 | |
| Total | 72 (100.0) | 272 (100.0) | 344 | |
| Parity‡ | ||||
| 1 child | 40 (55.6) | 160 (60.2) | 200 | p=0.482 |
| 2+ children | 32 (44.4) | 106 (39.8) | 138 | |
| Total | 72 (100.0) | 266 (100.0) | 338 | |
| Mode of last birth | ||||
| Vaginal** | 55 (76.4) | 196 (72.1) | 251 | p=0.462 |
| Caesarean section†† | 17 (23.6) | 76 (27.9) | 93 | |
| Total | 72 (100.0) | 272 (100.0) | 344 |
*Merged groups ‘16–17 years’ and ‘18–24 years’.
†Merged groups ‘35-39 years’ and ‘≥40 years’.
‡Variable with less than 10 values missing.
§Merged groups ‘single and never married’, ‘widowed’ and ‘divorced or separated'.
¶Merged groups ‘married’ and ‘living with a man/woman as a couple’.
**Merged groups ‘normal vaginal delivery’ and ‘forceps/vacuum delivery’.
††Merged groups ‘caesarean (emergency)’ and ‘caesarean (elective)’.
ATSI, Aboriginal or Torres Strait Islander background; IPI, interpregnancy interval; TAFE, technical and further education.