Table 1.
Cox regression results for risks of undergoing pelvic floor surgery (POP, UI and/or RP-FI)
| Risk factor | All women (N=34 631) | No operation (N=32 501) | Operation (N=2130) | Unadjusted |
Adjusted |
||
| N (%) | N (%) | N (%) | HR (95% CI) | p Value | HR (95% CI) | p Value | |
| Mode of delivery | |||||||
| SVD/breech only | 21 210 (61.2%) | 19 776 (60.8%) | 1434 (67.3%) | 1.00 | |||
| CS only | 2551 (7.4%) | 2524 (7.8%) | 27 (1.3%) | 0.25 (0.16 to 0.36) | <0.001 | 0.27 (0.18 to 0.39) | <0.001 |
| Instrumental (at least one forceps) | 9022 (26.1%) | 8433 (25.9%) | 589 (27.7%) | 1.14 (1.03 to 1.26) | 0.007 | 1.13 (1.02 to 1.25) | 0.015 |
| Instrumental (at least one, but no forceps) | 663 (1.9%) | 639 (2.0%) | 24 (1.1%) | 1.42 (0.95 to 2.13) | 0.09 | 1.35 (0.90 to 2.02) | 0.15 |
| SVD+CS | 1185 (3.4%) | 1129 (3.5%) | 56 (2.6%) | 0.92 (0.70 to 1.20) | 0.53 | 0.89 (0.68 to 1.17) | 0.40 |
| Age at first delivery | |||||||
| Under 20 years | 5867 (16.9%) | 5510 (17.0%) | 357 (16.8%) | 0.88 (0.78 to 0.99) | 0.035 | 0.87 (0.78 to 0.98) | 0.021 |
| 20–29 years | 23 751 (68.6%) | 22 221 (68.4%) | 1530 (71.8%) | 1.00 | 1.00 | ||
| 30–49 years | 5013 (14.5%) | 4770 (14.7%) | 243 (11.4%) | 1.11 (0.97 to 1.28) | 0.12 | 1.34 (1.16 to 1.54) | <0.001 |
| Total number of deliveries | |||||||
| Single | 8699 (25.1%) | 8306 (25.6%) | 393 (18.5%) | 1.00 | 1.00 | ||
| 2–4 | 24 986 (72.1%) | 23 323 (71.8%) | 1663 (78.1%) | 1.41 (1.26 to 1.58) | <0.001 | 1.30 (1.16 to 1.46) | <0.001 |
| 5+ | 946 (2.7%) | 872 (2.7%) | 74 (3.5%) | 1.15 (0.90 to 1.48) | 0.27 | 1.10 (0.85 to 1.41) | 0.48 |
| Twins at some point | |||||||
| No | 34 148 (98.6%) | 32 044 (98.6%) | 2104 (98.8%) | 1.00 | |||
| Yes | 483 (1.4%) | 457 (1.4%) | 26 (1.2%) | 0.80 (0.54 to 1.17) | 0.25 | ||
| Time between deliveries | |||||||
| One delivery | 8699 (25.1%) | 8306 (25.6%) | 393 (18.5%) | 1.00 | |||
| All <2 years | 4151 (12.0%) | 3883 (11.9%) | 268 (12.6%) | 1.40 (1.19 to 1.63) | <0.001 | ||
| All ≥2 years | 16 510 (47.7%) | 15 463 (47.6%) | 1047 (49.2%) | 1.40 (1.24 to 1.57) | <0.001 | ||
| Mixture | 5271 (15.2%) | 4849 (14.9%) | 422 (19.8%) | 1.41 (1.23 to 1.62) | <0.001 | ||
| Type of perineal wound | |||||||
| No wound | 14 365 (41.5%) | 13 601 (41.8%) | 764 (35.9%) | 1.00 | 1.00 | ||
| All episiotomy | 9457 (27.3%) | 8852 (27.2%) | 605 (28.4%) | 1.19 (1.07 to 1.33) | 0.001 | 1.05 (0.94 to 1.18) | 0.37 |
| At least one third-degree tear | 162 (0.5%) | 150 (0.5%) | 12 (0.6%) | 1.99 (1.12 to 3.53) | 0.018 | 1.68 (0.95 to 2.97) | 0.076 |
| No perineal tears (lacerations only) | 10 647 (30.7%) | 9898 (30.5%) | 749 (35.2%) | 1.57 (1.41 to 1.73) | <0.001 | 1.36 (1.22 to 1.52) | <0.001 |
CS, caesarean section; POP, pelvic organ prolapse; RP-FI, rectal prolapse or faecal incontinence; SVD, spontaneous vaginal delivery; UI, urinary incontinence.