| Table 3: Relative risk of severe perineal lacerations with median episiotomy according to potential confounding factors
|
| Factor |
No. (and %) of women with severe laceration |
RR (and 95% CI) |
| Episiotomy |
No episiotomy |
| Type of delivery | |
| | |
| |
| Forceps | 435 |
(34.5) | 23 | (25.6) |
1.35 | (0.94-1.94) |
| Vacuum extraction | 232 |
(18.4) | 25 | (4.6) | 3.99 | (2.68-5.96) |
| Spontaneous | 239 |
(12.8) | 48 | (3.2) | 3.99 | (2.95-5.40) |
| Adjusted RR* | |
| | | 3.13 | (2.61-3.75) |
| Birth weight, g |
| | | | | |
| $ 4000 | 108 |
(34.5) | 12 | (11.1) | 3.11 | (1.78-5.41) |
| 3000-3999 | 676 |
(21.2) | 74 | (5.1) | 4.18 | (3.32-5.28) |
| < 3000 | 122 |
(13.6) | 10 | (1.8) | 7.72 | (4.09-14.59) |
| Adjusted RR | |
| | | 4.37 | (3.67-5.20) |
| Epidural analgesia |
| | | | | |
| Yes | 740 |
(22.1) | 69 | (4.7) | 4.69 | (3.70-5.96) |
| No | 164 |
(15.7) | 27 | (4.0) | 3.88 | (2.62-5.77) |
| Adjusted RR | |
| | | 4.49 | (3.76-5.36) |
| Shoulder dystocia |
| | | | | |
| Yes | 42 |
(34.4) | 1 | (3.7) | 9.30 | (1.34-64.61) |
| No | 864 |
(20.2) | 95 | (4.5) | 4.49 | (3.65-5.51) |
| Adjusted RR | |
| | | 4.55 | (3.81-5.43) |
| Baby's head circumference, cm |
| | | | | |
| > 35 | 371 |
(27.6) | 21 | (4.5) | 6.11 | (3.99-9.36) |
| # 35 | 512 |
(17.6) | 72 | (4.4) | 3.98 | (3.13-5.06) |
| Adjusted RR | |
| | | 4.52 | (3.77-5.41) |
| Year of delivery |
| | | | | |
| 1985-87 | 351 |
(20.9) | 22 | (4.6) | 4.59 | (3.02-6.97) |
| 1988-90 | 357 |
(21.7) | 32 | (3.9) | 5.54 | (3.90-7.88) |
| 1991-93 | 198 |
(18.6) | 42 | (5.1) | 3.68 | (2.67-5.07) |
| Adjusted RR | |
| | | 4.57 | (3.82-5.47) |
| No. of yr of practice of physician |
| | | | | |
| > 10 | 704 |
(19.9) | 79 | (4.4) | 4.57 | (3.65-5.73) |
| # 10 | 202 |
(23.5) | 17 | (5.3) | 4.42 | (2.74-7.13) |
| Adjusted RR |
| | | | 4.54 |
(3.81-5.42) |
|
*RR of lacerations with median episiotomy adjusted for the variable of interest by the Mantel-Haenszel method. |
