Table 3. Relative risk of mild perineal trauma among the variables studied, after multivariate analysis.
| Crude | Adjusted | |||
|---|---|---|---|---|
| Odds ratio | 95% CI | Odds ratio | 95% CI | |
| Maternal age (years) | ||||
| ≤ 19 versus 20- 35 | 0.63 | (0.54- 0.74) | 1.12 | (0.79-1.57) |
| 20-35 versus > 35 | 1.03 | (0.90- 1.17) | 0.87 | (0.66-1.15) |
| Body position during professional activity | ||||
| Standing versus sitting | 1.04 | (0.94-1.14) | 0.96 | (0.81-1.14) |
| Body mass index | ||||
| Obese versus normal | 1.17 | (1.00-1.37) | 1.01 | (0.79-1.30) |
| Overweight versus normal | 1.08 | (0.95-1.24) | 1.06 | (0.85-1.31) |
| Previous vaginal delivery | ||||
| No versus yes | 0.63 | (0.58-0.68) | 1.64 | (1.33-2.04) |
| Use of oxytocin | ||||
| Yes versus no | 0.90 | (0.83-0.97) | 1.03 | (0.86-1.23) |
| Length of time with ruptured membranes (h) | ||||
| 6-12 versus < 6 | 1.03 | (0.83-1.29) | 1.16 | (0.77-1.75) |
| 12-18 versus < 6 | 0.85 | (0.63-1.14) | 0.54 | (0.31-0.94) |
| > 18 versus < 6 | 0.94 | (0.68-1.30) | 1.47 | (0.79-2.71) |
| Second-stage duration (min) | ||||
| 30-60 versus > 60 | 0.89 | (0.68-1.17) | 1.00 | (0.61-1.65) |
| < 30 versus > 60 | 1.77 | (1.45-2.16) | 1.13 | (0.77-1.68) |
| Episiotomy | ||||
| No versus yes | 5.27 | (4.57- 6.09) | 9.93 | (7.41-13.31) |
| Locoregional analgesia | ||||
| No versus yes | 1.27 | (1.17-1.37) | 1.05 | (0.88-1.24) |
| Assisted vaginal delivery | ||||
| Yes versus no | 0.48 | (0.39-0.60) | 2.04 | (1.39-2.97) |
| Cranial circumference (cm) | ||||
| > 33 versus ≤ 33 | 1.17 | (1.07-1.29) | 1.06 | (0.90-1.26) |
| Birth weight (g) | ||||
| 2700-3800 versus < 2700 | 1.00 | (0.87-1.15) | 1.03 | (0.90-1.26) |
| > 3800 versus < 2700 | 1.25 | (1.02-1.54) | 1.01 | (0.95-1.49) |
CI
= confidence interval