Kearney Rohna, Miller Janis M, Ashton-Miller James A, DeLancey John O L
University College Hospital, London, United Kingdom.
Obstet Gynecol. 2006 Jan;107(1):144-9. doi: 10.1097/01.AOG.0000194063.63206.1c.
To identify obstetric factors associated with development of levator ani injury after vaginal birth.
Magnetic resonance images were taken of the pelvic floor of 160 women 9 to 12 months after first term vaginal delivery. Half the women had de novo stress incontinence and half were continent controls. Abnormalities of the pubovisceral portion were identified on magnetic resonance as present or absent. Defect severity was further scored in each muscle from 0 (no defect) to 3 (complete muscle loss). A summed score for the 2 sides (0 to 6) was assigned and grouped as minor (0-3) or major (4-6). Obstetric details were collected. The association between obstetric variables and muscle injury were analyzed using Fisher exact test and t tests.
The following increased odds ratios for levator defect were found: forceps use 14.7 (95% confidence interval [CI] 4.9-44.3), anal sphincter rupture 8.1 (95% CI 3.3-19.5) and episiotomy 3.1 (95% CI 1.4-7.2) but not vacuum delivery 0.9 (95% CI 0.19-4.3), epidural use 0.9 (95% CI 0.4-2.0), or oxytocin use 0.8 (95% CI 0.3-1.8). Women with levator injury were 3.5 years older and had a 78-minute longer second stage of labor. Differences in gestational age, birth weight, and head circumference were not statistically significant. A major defect in the pubovisceral muscle was seen in 22 women and a minor defect in 7 women.
Injuries to the levator ani muscles in women after their first vaginal delivery are associated with several obstetric factors indicating difficult vaginal birth and with older age.
II-3.
确定与阴道分娩后肛提肌损伤发生相关的产科因素。
对160名初产妇在首次足月阴道分娩后9至12个月进行盆底磁共振成像检查。其中一半女性有新发压力性尿失禁，另一半为无尿失禁的对照者。通过磁共振成像确定耻骨内脏肌部分有无异常。对每块肌肉的缺损严重程度进一步评分，从0（无缺损）到3（肌肉完全缺失）。计算两侧的总分（0至6），并分为轻度（0 - 3）或重度（4 - 6）。收集产科详细信息。使用Fisher精确检验和t检验分析产科变量与肌肉损伤之间的关联。
发现以下因素使肛提肌缺损的比值比增加：使用产钳为14.7（95%置信区间[CI]4.9 - 44.3），肛门括约肌破裂为8.1（95%CI 3.3 - 19.5），会阴切开术为3.1（95%CI 1.4 - 7.2），而使用真空吸引器为0.9（95%CI 0.19 - 4.3），使用硬膜外麻醉为0.9（95%CI 0.4 - 2.0），使用缩宫素为0.8（95%CI 0.3 - 1.8）。有肛提肌损伤的女性年龄大3.5岁，第二产程长78分钟。孕周、出生体重和头围的差异无统计学意义。22名女性耻骨内脏肌有重度缺损，7名女性有轻度缺损。
女性首次阴道分娩后肛提肌损伤与多种表明阴道分娩困难的产科因素及年龄较大有关。
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