Table 3. Hazard Ratios (HRs) for Pelvic Floor Disordersa.
| Stress Urinary Incontinence (n = 1360) | Overactive Bladder (n = 1430) | Anal Incontinence (n = 1361) | Pelvic Organ Prolapse (n = 1492) | |||||
|---|---|---|---|---|---|---|---|---|
| HR (95% CI) | aHR (95% CI) | HR (95% CI) | aHR (95% CI) | HR (95% CI) | aHR (95% CI) | HR (95% CI) | aHR (95% CI) | |
| Person-years | 5892 | 6383 | 5737 | 6424 | ||||
| Cases | 138 | 117 | 168 | 153 | ||||
| Delivery mode group | ||||||||
| Cesarean | 0.49 (0.34-0.71) | 0.46 (0.32-0.67) | 0.54 (0.36-0.80) | 0.51 (0.34-0.76) | 0.77 (0.55-1.08) | 0.72 (0.51-1.02) | 0.29 (0.19-0.43) | 0.28 (0.19-0.42) |
| Spontaneous vaginal | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Operative vaginal | 0.99 (0.60-1.64) | 1.07 (0.65-1.78) | 1.07 (0.63-1.83) | 1.07 (0.63-1.84) | 1.70 (1.11-2.59) | 1.75 (1.14-2.68) | 1.78 (1.21-2.60) | 1.88 (1.28-2.78) |
| Age at first delivery, y | ||||||||
| <30 | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| 30-34 | 0.75 (0.50-1.12) | 0.80 (0.53-1.21) | 1.11 (0.72-1.72) | 1.10 (0.70-1.73) | 1.07 (0.74-1.55) | 1.03 (0.71-1.49) | 0.89 (0.61-1.30) | 0.94 (0.64-1.37) |
| ≥35 | 0.92 (0.61-1.38) | 0.96 (0.62-1.48) | 1.26 (0.80-1.96) | 1.20 (0.74-1.94) | 1.33 (0.92-1.92) | 1.36 (0.92-2.01) | 0.98 (0.67-1.45) | 1.33 (0.88-2.01) |
| Race | ||||||||
| Nonblack | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Black | 1.02 (0.64-1.62) | 0.86 (0.52-1.42) | 1.06 (0.63-1.78) | 1.08 (0.62-1.87) | 0.46 (0.27-0.80) | 0.42 (0.24-0.73) | 0.84 (0.52-1.36) | 0.99 (0.60-1.65) |
| Parity | ||||||||
| 1 | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| 2 | 0.80 (0.54-1.19) | 0.82 (0.54-1.23) | 0.87 (0.58-1.30) | 0.88 (0.57-1.36) | 1.28 (0.89-1.85) | 1.37 (0.93-2.02) | 1.96 (1.25-3.06) | 2.07 (1.31-3.30) |
| ≥3 | 1.16 (0.72-1.87) | 1.13 (0.67-1.88) | 0.57 (0.31-1.06) | 0.56 (0.29-1.08) | 1.05 (0.63-1.75) | 1.12 (0.65-1.91) | 2.14 (1.26-3.64) | 2.08 (1.19-3.64) |
| BMI | ||||||||
| <25 | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| 25-29 | 1.25 (0.83-1.88) | 1.32 (0.87-2.00) | 0.72 (0.46-1.14) | 0.76 (0.48-1.21) | 1.21 (0.84-1.76) | 1.37 (0.94-1.99) | 0.97 (0.66-1.42) | 1.11 (0.76-1.63) |
| ≥30 | 1.62 (1.09-2.41) | 1.97 (1.29-3.01) | 1.02 (0.66-1.57) | 1.14 (0.72-1.81) | 1.59 (1.11-2.29) | 2.24 (1.53-3.20) | 0.97 (0.66-1.43) | 1.50 (0.99-2.26) |
| Genital hiatus size,b,c cm | ||||||||
| ≤2.5 | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| 3 | 1.84 (1.19-2.83) | 1.01 (0.59-1.73) | 1.65 (1.13-2.41) | 3.49 (2.02-6.03) | ||||
| ≥3.5 | 2.31 (1.57-3.40) | 2.09 (1.41-3.11) | 1.60 (1.12-2.27) | 11.74 (7.51-18.4) | ||||
Abbreviations: aHR, adjusted hazard ratio; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared).
a
Hazard ratios were derived from bivariable analysis and adjusted hazard ratios were derived from multivariable analysis .
b
The genital hiatus size is the distance from the middle of the external urethral meatus to the posterior midline hymen, measured during the Valsalva maneuver.
c
Genital hiatus size was not included in the multivariable analysis because this variable is likely to be in causal pathway of delivery mode.