|
Table 2: Frequency and relative risk of severe (third- and fourth-degree) perineal lacerations according to various factors |
| Factor |
No. (and %) of women with severe laceration |
RR (and 95% CI)* |
|
Median episiotomy |
| | | |
| Yes | 906/4390 |
(20.6) | 4.58 | (3.74-5.62) |
| No | 96/2132 |
(4.5) | 1.00 | |
|
Type of delivery | | | | |
| Forceps |
458/1350 | (33.9) | 3.99 | (3.49-4.56) |
| Vacuum extraction |
257/1798 | (14.3) | 1.68 | (1.43-1.97) |
| Spontaneous |
287/3374 | (8.5) | 1.00 | |
| Epidural analgesia | |
| | |
| Yes |
810/4812 | (16.8) | 1.50 | (1.29-1.74) |
| No |
192/1710 | (11.2) | 1.00 | |
| Birth weight, g | |
| | |
| $ 4000 |
120/421 | (28.5) | 3.15 | (2.53-3.94) |
| 3000-3999 |
750/4641 | (16.2) | 1.79 | (1.50-2.13) |
| < 3000 |
132/1460 | (9.0) | 1.00 | |
| Shoulder dystocia | |
| | |
| Yes |
43/149 | (28.8) | 1.92 | (1.48-2.48) |
| No | 959/6373 |
(15.0) | 1.00 | |
| Baby's head circumference, cm |
| | | |
| > 35 |
392/1810 | (21.6) | 1.68 | (1.50-1.89) |
| # 35 |
584/4528 | (12.9) | 1.00 | |
| Gestational age, wk |
| | | |
| $ 41 |
317/1836 | (17.3) | 2.37 | (1.54-3.66) |
| 37-40 |
665/4411 | (15.1) | 2.07 | (1.35-3.18) |
| < 37 |
20/275 | (7.3) | 1.00 | |
| Maternal age, yr |
| | | |
| $ 35 |
51/321 | (15.9) | 1.69 | (1.10-2.61) |
| 30-34 |
247/1367 | (18.1) | 1.92 | (1.33-2.79) |
| 25-29 |
457/2978 | (15.3) | 1.63 | (1.14-2.35) |
| 20-24 |
219/1558 | (14.0) | 1.50 | (1.03-2.17) |
| < 20 |
28/298 | (9.4) | 1.00 | |
| Year of delivery |
| | | |
| 1985-87 |
373/2163 | (17.2) | 1.36 | (1.17-1.58) |
| 1988-90 |
389/2461 | (15.8) | 1.25 | (1.08-1.45) |
| 1991-93 |
240/1898 | (12.6) | 1.00 | |
| Type of physician |
| | | |
| Obstetrician-gynecologist |
770/4942 | (15.6) | 1.06 | (0.93-1.22) |
| Family physician |
232/1580 | (14.7) | 1.00 | |
| No. of yr of practice of physician |
| | | |
| # 10 |
219/1177 | (18.6) | 1.27 | (1.11-1.46) |
| > 10 |
783/5345 | (14.6) | 1.00 | |
| Average yearly no. of deliveries of physician |
| | | |
| < 100 |
262/1791 | (14.6) | 0.94 | (0.82-1.07) |
| $ 100 |
740/4731 | (15.6) | 1.00 | |
| Attending physician's belief |
| | | |
| Strong believer |
239/1799 | (13.3) | 0.97 | (0.81-1.16) |
| Believer |
357/2299 | (15.5) | 1.13 | (0.96-1.37) |
| Nonbeliever |
181/1321 | (13.7) | 1.00 | |
|
*RR = relative risk, CI = confidence interval.
|
