Clemons Jeffrey L, Towers Geoffrey D, McClure George B, O'Boyle Amy L
Division of Urogynecology and Pelvic Reconstructive Surgery, Department of Obstetrics and Gynecology, Madigan Army Medical Center, Tacoma, Wash 98431, USA.
Am J Obstet Gynecol. 2005 May;192(5):1620-5. doi: 10.1016/j.ajog.2004.11.017.
To determine whether restrictive episiotomy use was associated with decreases in anal sphincter lacerations and the risk of anal sphincter laceration attributable to episiotomy.
This was a retrospective database study. Rates of episiotomy, anal sphincter laceration (third- or fourth-degree tear), and other confounding variables were compared among vaginal deliveries before (1999) and after (2002) restrictive episiotomy use was implemented at our institution. Logistic regression was used to estimate the odds ratio of anal sphincter laceration that was due to episiotomy and other variables.
The episiotomy rate decreased 56% (37% to 17%, P < .001) between 1999 and 2002, whereas the anal sphincter laceration rate decreased 44% (9.7% to 5.4%, P < .001). There were no changes in age, race, nulliparity, prolonged second stage of labor, operative vaginal deliveries, birth weight, or macrosomia, although oxytocin use and epidural use decreased slightly (37% to 31%, P < .001, and 80% to 76%, P = .02, respectively). The adjusted odds ratio of anal sphincter laceration attributable to episiotomy decreased 55%, from 6.5 (95% CI: 3.8, 11.1) to 2.9 (95% CI: 1.7, 5.0), between 1999 and 2002. Conversely, the adjusted odds ratios of anal sphincter laceration attributable to the other independent risk factors all increased or remained the same: operative vaginal delivery, which increased from 4.4 (95% CI: 2.7, 6.9) to 6.3 (95% CI: 3.6 11.1); nulliparity, from 2.9 (95% CI: 1.8, 4.8) to 2.9 (95% CI: 1.4, 5.9); macrosomia, from 1.9 (95% CI: 1.1, 3.4) to 2.6 (95% CI: 1.3, 5.4); and prolonged second stage, from 2.0 (95% CI: 1.3, 3.0) to 2.1 (95% CI: 1.2, 3.7).
With restrictive episiotomy use, the episiotomy rate, anal sphincter laceration rate, and risk of anal sphincter laceration attributable to episiotomy were all reduced by approximately 50%.
确定限制性会阴切开术的使用是否与肛门括约肌裂伤的减少以及因会阴切开术导致的肛门括约肌裂伤风险相关。
这是一项回顾性数据库研究。在我们机构实施限制性会阴切开术之前（1999年）和之后（2002年）的阴道分娩中，比较了会阴切开术、肛门括约肌裂伤（三度或四度撕裂）以及其他混杂变量的发生率。使用逻辑回归来估计因会阴切开术和其他变量导致的肛门括约肌裂伤的比值比。
1999年至2002年间，会阴切开术发生率下降了56%（从37%降至17%，P<.001），而肛门括约肌裂伤发生率下降了44%（从9.7%降至5.4%，P<.001）。年龄、种族、初产情况、第二产程延长、阴道助产、出生体重或巨大儿情况均无变化，不过催产素使用和硬膜外麻醉使用略有下降（分别从37%降至31%，P<.001；从80%降至76%，P=.02）。1999年至2002年间，因会阴切开术导致的肛门括约肌裂伤的校正比值比下降了55%，从6.5（95%CI：3.8，11.1）降至2.9（95%CI：1.7，5.0）。相反，因其他独立危险因素导致的肛门括约肌裂伤的校正比值比均有所增加或保持不变：阴道助产，从4.4（95%CI：2.7，6.9）增至6.3（95%CI：3.6，11.1）；初产情况，从2.9（95%CI：1.8，4.8）至2.9（95%CI：1.4，5.9）；巨大儿，从1.9（95%CI：1.1，3.4）至2.6（95%CI：1.3，5.4）；以及第二产程延长，从2.0（95%CI：1.3，3.0）至2.1（95%CI：1.2，3.7）。
采用限制性会阴切开术时，会阴切开术发生率、肛门括约肌裂伤发生率以及因会阴切开术导致的肛门括约肌裂伤风险均降低了约50%。
