Table 1.
Characteristics of older and comparison women
| Characteristic | Number (%)a of older women (n = 233) | Number (%)a of comparison women (n = 454) | Unadjusted OR (95% CI) | P‐value |
|---|---|---|---|---|
| Sociodemographic characteristics | ||||
| Ethnic group | ||||
| White | 165 (71) | 323 (71) | 1 | |
| Non‐White | 67 (29) | 129 (29) | 1.02 (0.72–1.44) | 0.9259 |
| Marital status | ||||
| Married or cohabiting | 194 (85) | 375 (84) | 1 | |
| Single | 35 (15) | 71 (16) | 0.95 (0.61–1.48) | 0.8299 |
| Socio‐economic group | ||||
| Managerial and professional occupations | 91 (39) | 144 (32) | 1 | |
| Other | 103 (44) | 231 (51) | 0.71 (0.50–1.00) | 0.0511 |
| Missing | 39 (17) | 79 (17) | ||
| Body mass index (kg/m2) | ||||
| <25 | 101 (44) | 260 (58) | 1 | |
| 25–29.9 | 75 (33) | 103 (23) | 1.87 (1.29–2.73) | 0.0011 |
| ≥30 | 52 (23) | 85 (19) | 1.57 (1.04–2.38) | 0.0318 |
| Smoking status | ||||
| Never/ex smoker | 226 (99) | 407 (90) | 1 | |
| Smoked during pregnancy | 3 (1) | 45 (10) | 0.12 (0.04–0.39) | 0.0004 |
| Previous medical history | ||||
| Previous uterine surgery not including previous caesarean section | ||||
| No | 168 (74) | 418 (93) | 1 | |
| Yes | 60 (26) | 33 (7) | 4.52 (2.85–7.17) | <0.0001 |
| Previous or pre‐existing medical condition | ||||
| No | 129 (56) | 328 (72) | 1 | |
| Yes | 101 (44) | 126 (28) | 2.04 (1.46–2.84) | <0.0001 |
| Pregnancy‐related characteristics | ||||
| Parity | ||||
| 0 | 122 (53) | 200 (44) | 1 | |
| 1 or more | 108 (47) | 252 (56) | 0.7 (0.51–0.97) | 0.0299 |
| Previous caesarean section | ||||
| No | 179 (79) | 379 (84) | 1 | |
| Yes | 49 (21) | 72 (16) | 1.44 (0.96–2.16) | 0.0765 |
| Multiple pregnancy | ||||
| No | 189 (82) | 444 (98) | 1 | |
| Yes | 41 (18) | 10 (2) | 9.63 (4.73–19.63) | <0.0001 |
| Conceived following assisted conception | ||||
| No | 50 (22) | 425 (96) | 1 | |
| Yes | 176 (78) | 19 (4) | 78.74 (45.13–137.38) | <0.0001 |
a
Percentage of individuals with complete data unless missing category shown.